5 research outputs found
Magnetic hyperthermia with Δ-Fe2O3 nanoparticles
Biocompatibility restrictions have limited the use of magnetic nanoparticles for magnetic hyperthermia therapy to iron oxides, namely magnetite (Fe3O4) and maghemite (Îł-Fe2O3). However, there is yet another magnetic iron oxide phase that has not been considered so far, in spite of its unique magnetic properties: Δ-Fe2O3. Indeed, whereas Fe3O4 and Îł-Fe2O3 have a relatively low magnetic coercivity, Δ-Fe2O3 exhibits a giant coercivity. In this report, the heating power of Δ-Fe2O3 nanoparticles in comparison with Îł-Fe2O3 nanoparticles of similar size (âŒ20 nm) was measured in a wide range of field frequencies and amplitudes, in uncoated and polymer-coated samples. It was found that Δ-Fe2O3 nanoparticles primarily heat in the low-frequency regime (20â100 kHz) in media whose viscosity is similar to that of cell cytoplasm. In contrast, Îł-Fe2O3 nanoparticles heat more effectively in the high frequency range (400â900 kHz). Cell culture experiments exhibited no toxicity in a wide range of nanoparticle concentrations and a high internalization rate. In conclusion, the performance of Δ-Fe2O3 nanoparticles is slightly inferior to that of Îł-Fe2O3 nanoparticles in human magnetic hyperthermia applications. However, these Δ-Fe2O3 nanoparticles open the way for switchable magnetic heating owing to their distinct response to frequency.This work was supported by European Union's Horizon 2020 FET Open program [Grants no: 801305 and 829162] Spanish Ministry of Science Innovation and Universities [Grant no: PGC2018_095795_B_I00] and DiputaciĂłn General de AragĂłn [E11/17R]. Authors would like to acknowledge the use of Servicio General de Apoyo a la InvestigaciĂłn-SAI, Universidad de Zaragoza. This work was developed within the scope of the projects CoolPoint P2020-PTDC-CTMNAN-4511-2014 and CICECO-Aveiro Institute of Materials, UIDB/50011/2020 & UIDP/50011/2020, financed by national funds through the FCT/MEC and co-financed by FEDER under the PT2020 Partnership Agreement.We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI).Peer reviewe
Restes humains de NouvelleâCalĂ©donie, une source historique peu exploitĂ©e (Les)
AuâdelĂ de sa dimension musĂ©ale et scientifique, la collection de restes humains provenant de NouvelleâCalĂ©donie et conservĂ©e au MusĂ©um national dâHistoire naturelle de Paris, apparaĂźt Ă lâhistorien comme une source importante pour servir non seulement lâhistoire des sciences, en particulier lâanthropologie et la mĂ©decine, lâhistoire des collections musĂ©ales, mais aussi les politiques coloniales fondĂ©es sur les relations savoirs/pouvoirs et centre/pĂ©riphĂ©ries.Beyond its museum and scientific dimension, this collection of human remains from NewâCaledonia, kept at the National Museum of Natural History of Paris, appears to the historian as an important source to serve not only the history of science, especially anthropology, medicine, and the history of museum collections, but also colonial policies based on knowledge/power and center/peripheries relations
Health effects of ionising radiation in paediatrics undergoing either cardiac fluoroscopy or modern radiotherapy (The HARMONIC project)
The use of ionising radiation (IR) for medical diagnosis and treatment procedures has had a major impact on the survival of paediatric patients. Although the benefits of these techniques lead to efficient health care, evaluation of potential associated long-term health effects is required. HARMONIC aims to better understand the increased risk of cancer and non-cancer effects after exposure to medical IR in children with cancer treated with modern external beam radiotherapy (EBRT) â radiation energy in MeV range â and in children with cardiac defects diagnosed and treated with cardiac fluoroscopy procedures (CFP) â radiation energy in keV range. The project investigates, among survivors of paediatric cancer, potential endocrine dysfunction, cardiovascular and neurovascular damage, health-related quality of life and second (and subsequent) primary cancer (SPC). The cardiac component builds a pooled cohort of approximately 90 000 paediatric patients who underwent CFP during childhood and adolescence to investigate cancer risk following exposure to IR and explore the potential effects of conditions predisposing to cancer. HARMONIC develops software tools to allow dose reconstruction in both EBRT and CFP to enable epidemiological investigations and future optimisation of treatments. With the creation of a biobank of blood and saliva samples, HARMONIC aims to provide a mechanistic understanding of radiation-induced adverse health effects and identify potential biomarkers that can predict these effects
Encyclopédie des historiographies : Afriques, Amériques, Asies
Quels rapports les sociĂ©tĂ©s humaines entretiennent-elles avec leur passĂ© et quels rĂ©cits font-elles du temps rĂ©volu ? Pour ce premier volume de lâEncyclopĂ©die des historiographies. Afriques, AmĂ©riques, Asies, 157 spĂ©cialistes reprĂ©sentant 88 institutions acadĂ©miques en France et dans le monde explorent lâunivers des productions humaines qui constituent des sources pour lâhistorien et dĂ©chiffrent les nombreuses modalitĂ©s (« scientifiques », littĂ©raires, artistiques, monumentalesâŠ) de lâĂ©criture du passĂ©. Ăvoquant tour Ă tour lâAfrique, lâAmĂ©rique latine, lâAsie, lâOcĂ©anie, les 216 notices de lâouvrage prĂ©sentent des matĂ©riaux historiques de toute nature, issus de toutes les Ă©poques, souvent mĂ©connus, ainsi que lâhistoire de leurs usages. Lâentreprise collective quâest lâEncyclopĂ©die se veut novatrice : il sâagit de susciter une rĂ©flexion historiographique rĂ©solument non-occidentalo-centrĂ©e qui complĂšte utilement les dĂ©marches Ă©pistĂ©mologiques traditionnelles. Nouvel outil de connaissance historique forgĂ© Ă lâheure de la mondialisation, lâEncyclopĂ©die des historiographies est aussi une vĂ©ritable invitation au voyage.What are the different types of relations that non-Western societies upkeep with their past and how are narratives about the past produced by them? In this first volume of the Encyclopaedia of Historiography: Africa, America, Asia, 157 specialists from 88 international academic institutions explore the wealth of evidence that constitutes source material for historians. They also examine the immensely diverse modes or genres of narrated history: âscientificâ, literary, artistic, architectural, etc. 216 entries dealing with Africa, Latin America, Oceania, and Asia, cover a large variety of sources, including many which are unfamiliar to the Western or non-Western reader, along with the history of how they have been exploited. By bringing together for the first time such an abundance of material the reader is offered the possibility of exploring continents and building meaningful connections across space and time. In addition to being a new tool for historical enquiry in an era of globalization, this encyclopaedia is also an invitation to travel the world