HAL Portal UTC Université de Technologie de Compiègne
Not a member yet
11652 research outputs found
Sort by
Projet B2LIVE (Batteries de 2nde vie au Lithium Ion à Vieillissement caractérisé par Expérimentation)
No full text
Interface cognitive des individus et des artefacts numériques : une étude de la perception sensorielle et cognitive
No full textInternational audienc
Carotenoids bioproduction by two psychrophilic microalgae: Sphaerocystis sp. and Pleurastrum sp.
No full textInternational audienceAmong the valuable compounds derived from microalgae, carotenoids are the most studied. Carotenoids in plants, algae, and some photosynthetic bacteria and yeasts are responsible for their red, orange, and yellow pigmentation. Indeed, natural carotenoids receive significant interest because they are potent antioxidants and can protect against certain diseases such as cancer. Therefore, carotenoids derived from microalgae are valued for their diverse applications in food, feed, cosmetic, and pharmaceutical industries. In recent decades, the carotenoids industry has searched for sources other than Haematococcus pluvialis microalga. This mesophilic microalga (temperature growth between 25°- 28° C) represents the most abundant source of natural astaxanthin, a well-known antioxidant and one of the most expensive carotenoids on the market. However, few studies have been conducted on extremophilic microalgae strains that can produce valuable carotenoids at low temperatures and light. The cultivation of microalgae requires artificial lighting to mimic natural sunlight. These lights consume a substantial electricity input. In addition, maintaining the ideal temperature and climate for microalgae growth involves heating or cooling systems, which further contribute to energy consumption. In regions where energy costs are high or renewable sources are limited, the cost of energy consumption can become prohibitive. Hence, studies were performed to find microalgae strains that are more tolerant or adapted. In this context, psychrophilic microalgae represent potent candidates because they are well-adapted to harsh environments in cold-climate regions. Moreover, these photosynthetic organisms cause red, orange, yellow, or brown pigmentations when snow fields are subject to extensive irradiation, high temperature, and low nutrient availability (melting season). This project is devoted to optimizing carotenoid bioaccumulation by two selected psychrophilic strains Sphaerocystis sp. and Pleurastreum sp. Both are successfully acclimated to our laboratory conditions for the growth and accumulation of carotenoids. The culture was carried out through two stages (green and red), where parameters such as temperature, lighting, and nutritional medium were carefully monitored. Therefore, the first interesting results of culture pigmentation, cell stages transitioning, and pigment content of Chlorophyll a, Chlorophyll b, and total carotenoids are presented in this work
Synthetic Peptide Antibodies as TNF‐α Inhibitors: Molecularly Imprinted Polymer Nanogels Neutralize the Inflammatory Activity of TNF‐α in THP‐1 Derived Macrophages
No full textInternational audienceTumor Necrosis Factor‐α (TNF‐α) is a cytokine that is normally produced by immune cells when fighting an infection. But, when too much TNF‐α is produced as in autoimmune diseases, this leads to unwanted and persistent inflammation. Anti‐TNF‐α monoclonal antibodies have revolutionized the therapy of these disorders by blocking TNF‐α and preventing its binding to TNF‐α receptors, thus suppressing the inflammation. Herein, we propose an alternative in the form of molecularly imprinted polymer nanogels (MIP‐NGs). MIP‐NGs are synthetic antibodies obtained by nanomoulding the 3‐dimensional shape and chemical functionalities of a desired target in a synthetic polymer. Using an in‐house developed in silico rational approach, epitope peptides of TNF‐α were generated and ‘synthetic peptide antibodies’ were prepared. The resultant MIP‐NGs bind the template peptide and recombinant TNF‐α with high affinity and selectivity, and can block the binding of TNF‐α to its receptor. Consequently they were applied to neutralize pro‐inflammatory TNF‐α in the supernatant of human THP‐1 macrophages, leading to a downregulation of the secretion of pro‐inflammatory cytokines. Our results suggest that MIP‐NGs, which are thermally and biochemically more stable and easier to manufacture than antibodies, and cost‐effective, are very promising as next generation TNF‐α inhibitors for the treatment of inflammatory diseases
Molecularly Imprinted Polymers as Synthetic Antibodies for Protein Recognition: The Next Generation
No full textInternational audienceMolecularly imprinted polymers (MIPs) are chemical antibody mimics obtained by nanomoulding the 3D shape and chemical functionalities of a desired target in a synthetic polymer. Consequently, they possess exquisite molecular recognition cavities for binding the target molecule, often with specificity and affinity similar to those of antigen‐antibody interactions. Research on MIPs targeting proteins began in the mid‐90s, and this review will evaluate the progress made till now, starting from their synthesis in a monolith bulk format through surface imprinting to biocompatible soluble nanogels prepared by solid‐phase synthesis. MIPs in the latter format will be discussed more in detail because of their tremendous potential of replacing antibodies in the biomedical domain like in diagnostics and therapeutics, where the workforce of antibodies is concentrated. Emphasis is also put on the development of epitope imprinting, which consists of imprinting a short surface‐exposed fragment of a protein, resulting in MIPs capable of selectively recognizing the whole macromolecule, amidst others in complex biological media, on cells or tissues. Thus selecting the ‘best’ peptide antigen is crucial and in this context a rational approach, inspired from that used to predict peptide immunogens for peptide antibodies, is described for its unambiguous identification
Régimes d'accumulation et d'appropriation et flux de matières en longue période
No full textInternational audienceCe chapitre explore les liens entre régimes d’accumulation et d’appropriation, et flux de matières. Il détaille d’abord les conditions d’une alliance entre théorie de la régulation et l’économie écologique. Illustre, ensuite, les gains pour l’analyse sur la crise du fordisme. Et conclut sur un appel à de nouveaux travaux qui contribuent à une meilleure intelligibilité du capitalocène
Mutations récentes, dynamiques actuelles et perspectives de transition des territoires ruraux périurbains en Tunisie
No full textInternational audienceDouze ans après la « Révolution de Jasmin », la Tunisie traverse une profonde crise économique qui touche plus particulièrement ses territoires ruraux. Alors que le pays se doit de promouvoir un autre modèle agricole afin de répondre aux aspirations populaires en matière d’emploi rural et de production alimentaire, le présent article propose d’évaluer les perspectives de transition des territoires ruraux périurbains où se jouent plus particulièrement l’intégration économique des agriculteurs familiaux et l’organisation des réseaux d’approvisionnement alimentaires des grandes villes tunisiennes. Pour cela, il s’appuie sur les résultats d’un travail de terrain conduit à Mahrès, dans la périphérie de Sfax, la deuxième ville du pays, où des entretiens ont été réalisés auprès des agents des services agricoles et des agriculteurs. En analysant leurs discours, cet article met en évidence les contraintes qui pèsent sur les petites exploitations, et met en évidence plusieurs facteurs limitant la mise en œuvre d’un processus de transition territoriale devant reposer sur la réorganisation des agriculteurs pour la mise en œuvre de pratiques agricoles durables et la satisfaction des demandes alimentaires
Formulation and Characterization of Chitin-Starch Bio-Based Wood Adhesive for the Manufacturing of Formaldehyde-Free Composite Particleboards
No full textInternational audienceThe increased concern surrounding both environmental and health impacts caused by the use of formaldehyde-based wood adhesives has given rise to an urgent need for a shift in focus to alternative wood adhesives. The present study aims to develop environmentally friendly particleboards bonded using bio-based wood adhesive. The purpose of this work is the extraction of chitin (CH) from shrimp shell waste and its application in formulating alternative wood adhesives. The as-extracted CH has been characterized by scanning electron microscopy, Attenuated total reflectance-Fourier transform infrared, X-ray powder diffraction, and thermogravimetric analysis. Moreover, the wood adhesives were formulated using corn-starch-Mimosa tannin (CSMT) mixtures with 4, 6, 8, and 10 wt% of CH. The mechanical results showed that the optimum amount of CH, 6 wt.% added to CSMT increased the average of internal bond modulus of elasticity, modulus of rupture, and surface of soundness by 26.22; 19.75; 43.61 and 19.89% compared to the control CSMT/CH (100/0; w/w), respectively. Regarding, the physical performances the values of thickness swelling and water absorption of the optimal wood adhesive CSMT/CH (94/6; w/w) were decreased compared to the control CSMT/CH (100/0; w/w), about 46.86 and 24.15% after 2 h, and 22.12 and 15.46% after 24 h of wetting in water, respectively. Contact angle measurement showed that CSMT/CH (94/6; w/w) exhibits hydrophobic character compared to control CSMT/CH (100/0; w/w). Based on the findings, this study suggest that CSMT/CH (w/w) wood adhesive can be used as a renewable and alternative solution for the manufacturing of bio-particleboards for exterior applications
Age-sensitive high density surface electromyogram indices for detecting muscle fatigue using core shape modelling
No full textInternational audienceThe purpose of this preliminary study was to examine age-sensitive High Density surface Electromyogram (HDsEMG) features by Core Shape Modelling (CSM) method. Fatiguing low force isometric contractions of the bicepsbrachii was performed by eight young (age, 24.40 ± 2.42 years) and five elderly (72.90 ± 2.21 years) males,while HD-sEMG recorded signals from the biceps brachii. The task was performed at 20 % maximal voluntarycontraction (MVC). From the recorded HD-sEMG signals, three Probability Density Function (PDF) shape distances (SD) measures the departure from Gaussianity, i.e. Left (LSD), Right (RSD), and Central (CSD), werederived by the CSM method from non-overlapping five-second windows until task failure. A linear regressionanalysis was then used to quantify the change of these shape parameters throughout the contraction. Theresultant slopes revealed that the elderly group showed a decreasing trend in PDF shape parameters as thecontraction approached task failure. In contrast, the young showed an increasing trend. Statistical differencesbetween the two groups were found for LSD (p = 0.006) and RSD (p = 0.001). No such age-sensitivity wasdetected using conventional sEMG fatigue features. These results suggest that the proposed CSM method can beused to obtain fatigue-related features from HD-sEMG that are age-sensitive and possibly related to differentmotor unit recruitment and synchronization schemes