HAL Portal Univ Catholille
Not a member yet
19763 research outputs found
Sort by
Acoustic tweezers for targeted drug delivery
No full textNo data was used for the research described in the article.International audienceAcoustic tweezers are a highly promising technology for targeted drug delivery thanks to their unique capabilities: (i) they can effectively operate in both in vitro and in vivo environments, (ii) they can manipulate a wide range of particle sizes and materials, and (iii) they can exert forces several orders of magnitude larger than competing techniques while remaining safe for biological tissues. In particular, tweezers capable of selectively capturing and manipulating objects in 3D with a single beam, known as 'single beam tweezers', open new perspectives for delivering drug carriers to precise locations. In this review, we first introduce the fundamental physical principles underlying the manipulation of particles using acoustic tweezers and highlight the latest advancements in the field. We then discuss essential considerations for the design of drug delivery carriers suitable for use with acoustic tweezers. Finally, we summarise recent promising studies that explore the use of acoustic tweezers for in vitro, ex vivo, and in vivo drug delivery
L’Asie est-elle la prochaine poudrière mondiale ?
No full textInternational audienceActualisation du livre éponyme édité par les deux auteurs aux éditions Le Cer
Piezoelectric Polymer Characterization Setup for Active Energy Harvesting
No full textInternational audiencePiezoelectric polymers, such as poly(vinylidene fluoride) (PVDF), offer a sustainable alternative to traditional ceramic‐based energy harvesters, addressing concerns regarding environmental impact and resource scarcity. The energy harvesting ability of these PVDFs under various mechanical constraints has been widely investigated. To determine the power output of the material, most of the studies usually use the same electrical setup: the piezoelectric material is in series with a load resistor and the voltage is measured at the resistor's terminals. This usual “passive” method of measurement can underestimate the optimal value of energy harvesting ability. To accurately assess the energy harvesting potential of PVDF, a novel “active” measurement method is proposed. This method involves the simultaneous application of both mechanical and electrical stimuli to the PVDF film, enabling precise control and optimization of the energy harvesting process. To validate this approach, the structural and electrical properties of the stretched PVDF were initially characterized to produce a datasheet. Subsequently, the energy harvesting performance was investigated using both “passive” and “active” methods. The results demonstrated a significant enhancement in power output, with the “active” method yielding up to 3.2 times higher values compared with the “passive” method. This finding highlights the importance of employing advanced measurement techniques to accurately characterize the energy harvesting capabilities of piezoelectric materials
Naturalness and Tree Composition Determine the Abundance of Rare and Threatened Orchids in Mature and Old-Growth Abies alba Forests in the Northern Apennines (Italy)
No full textInternational audienceForest Orchidaceae are important for European temperate forests, yet their distribution and abundance have so far interested limited research. In three pure or mixed silver fir stands in the Foreste Casentinesi National Park (NP) (Northern Apennines, Italy) we analysed how structural traits in mature and old-growth forests affected orchid communities in terms of abundance of the main genera, trophic strategy and rarity in the NP. We established three 20 × 60 m plots to quantify the structure of living and dead tree community, including a set of old-growth attributes connected to large trees, deadwood, and established regeneration. In each plot, we measured the abundance of all orchid species and explored their behaviour according to the trophic strategy (autotrophy/mixotrophy, obligate mycoheterotrophy), rarity within the NP, and threatened status according to the IUCN Red List. We used multivariate ordination and classification techniques to assess plot similarities according to forest structure and Orchid Community and identify the main structural factors related to orchid features. The main structural factors were used as predictors of community traits. Forest composition (i.e., the dominance/abundance of silver fir) affected the presence of the main orchid genera: Epipactis were abundant in silver fir-dominated forests, Cephalanthera in mixed beech and fir forests. Interestingly, Cephalanthera could become limited even in beech-dominated conditions if fir regeneration was abundant and established. Old-growth attributes like the density of deadwood and large tree volume were important determinants of the presence of rare and mycoheterotrophic species. Our results provided a first quantitative description of forest reference conditions to be used in the protection and restoration of threatened and rare orchid species
L’information du patient. Quand l’assignation à l’autonomie rencontre les inégalités sociales.
No full textInternational audienceLa figure du patient, son rôle et sa place dans le système de soins ont considérablement évolué : l’extensiondu droit des malades s’accompagnant d’une transformation de la relation médecin-patient et, en particulier,d’un basculement du registre de la passivité vers celui de l’autonomie et de la participation. Mais, le modèleparticipationniste permet-il néanmoins de couvrir toutes les formes d’échange en situation de soins ? Les notions de démocratie sanitaire, de patient acteur, autonome ou encore de soins négociés sont-elles réellement l’expression d’une démocratisation des relations entre médecins et patients ? Tous les patients aspirent-ils à choisir leur santé ? Et, surtout, disposent-ils tous des mêmes périmètres de négociations ? Pour répondre à ces questions, cette contribution propose de s’intéresser aux modalités effectives de participation des patients dans la relation de soin qu’ils entretiennent avec leurs soignants, à partir d’un corpus de données empiriques recueillies par observations et entretiens dans un établissement de soins en cancérologie. Tandis que les consultations constituent un lieu d’observation privilégié pour mieux comprendre la diversité des formes d’échanges entre médecins et patients, les entretiens avec les patients nous renseignent, quant à eux, sur leurs ambitions respectives en matière d’autonomie, de participation et d’implication dans les choix thérapeutiques qui les concernent. En conclusion, notre étude confirme que si un processus de démocratisation de l’information médicale s’est produit, cette évolution n’atteint pas prioritairement ceux qui en ont le plus besoin, mais les plus éduqués et les plus informés
L’exigence de l’explication en biologie à l’égard d’une philosophie de la morphogenèse
No full textInternational audienceÀ partir de la question de savoir comment la science peut expliquer, ce texte pose la question à l’égard des formes d’enquêtes qui semblent inaptes à prédire. La question du modèle d’explication qui admettrait des données statistiques est ensuite confrontée aux idéaux rigoureusement prédictivistes et peut-être subrepticement déterministes. En discutant du modèle confirmationniste, on tente ici de tirer les conséquences de l’absence de procédure qui puisse venir disconfirmer en contexte probabiliste. C’est l’occasion de s’interroger sur le mode de résolution des problèmes et défis dont fait montre la nature dans le but de reposer la question de la place de la téléologie eu égard à l’espace laissé oruvert par l’absence de procédures de validation. On est ainsi conduit à réinterroger la présence de schèmes d’économie d’énergie et d’optimalité qui rendent raison d’une anatomie transcendante, et puis finalement conduisent à s’interroger sur la place que tient la forme dans la vision que nous prenons de la nature
Fractures nationales : Retrait des services publics et dynamiques électorales
No full textInternational audienceL’objectif de cette étude est d’identifier les effets du retrait des équipements publics 1998-2018 sur les résultats des élections 2002-2022 en France. Différentes catégories de services publics sont définies, en fonction de la priorité accordée au bien-être de la population locale. Nous montrons ainsi que le retrait des services publics entraîne des votes populistes, à la fois à l’extrême gauche et à l’extrême droite, en particulier dans les communes les plus grandes. Les gains des partis d’extrême-gauche et d’extrême-droite se font en outre au détriment des partis traditionnels
From Private Surveillance to Public Protection: The Pervasive Interplay
No full textInternational audienc
Representation Styles
No full textInternational audienceThe debate around how representatives should take political decisions is a long-standing one in political studies, which traces back to philosophical disputes between supporters of independent judgment vis-à-vis those of politicians' delegate functions. During the 20th century, such normative debate gradually translated into an empirical stream of research focusing on the representative role orientations, more commonly defined as styles, of political candidates and representatives. This entry aims at summarizing such academic debate, stressing its relevance and future directions. The main take-home message is that representatives' role orientations are influenced by multiple factors, including individual, party and electoral system-level characteristics. In addition, representation styles have the potential to affect the quality of communications between voters and elites, as politicians holding specific styles have been found to be more accurate at understanding and reflecting their voters' policy interests. The entry concludes by mentioning recent studies exploring these issues from a transnational perspective