A balancing act: urban regeneration through arts & culture

Starting with the 1970s, major European cities successfully added arts and culture to their mix of urban renewal strategies. When art is part of the vision for a better city, streets are transformed into open-air galleries, buildings become alternative environments for creative expression, and the quality-of-life increases. This positive transformation tends to attract newcomers with higher income levels, which can lead to gentrification, a phenomenon which negatively affects local communities. Finding the equilibrium in this balancing act demands carefully planned urban regeneration strategies, aligned with local contexts and flexible enough to address the various needs of the long-term inhabitants

High temperature structural and magnetic properties of cobalt nanowires

We present in this paper the structural and magnetic properties of high aspect ratio Co nanoparticles (~10) at high temperatures (up to 623 K) using in situ X ray diffraction (XRD) and SQUID characterizations. We show that the anisotropic shapes, the structural and texture properties are preserved up to 500 K. The coercivity can be modelled by u0Hc=2(Kmc+Kshape)/Ms with Kmc the magnetocrystalline anisotropy constant, Kshape the shape anisotropy constant and Ms the saturation magnetization. Hc decreases linearly when the temperature is increased due to the loss of the Co magnetocrystalline anisotropy contribution. At 500K, 50% of the room temperature coercivity is preserved corresponding to the shape anisotropy contribution only. We show that the coercivity drop is reversible in the range 300 - 500 K in good agreement with the absence of particle alteration. Above 525 K, the magnetic properties are irreversibly altered either by sintering or by oxidation.Comment: 8 pages, 7 figures, submitted to Journal of Solid State Chemistr

Genetic reversal of the globin switch concurrently modulates both fetal and sickle hemoglobin and reduces red cell sickling

We previously reported initial clinical results of post-transcriptional gene silencing of BCL11A expression (NCT 03282656) reversing the fetal to adult hemoglobin switch. A goal of this approach is to increase fetal hemoglobin (HbF) expression while coordinately reducing sickle hemoglobin (HbS) expression. The resulting combinatorial effect should prove effective in inhibiting HbS polymerization at lower physiologic oxygen values thereby mitigating disease complications. Here we report results of exploratory single-cell analysis of patients in which BCL11A is targeted molecularly and compare results with cells of patients treated with hydroxyurea (HU), the current standard of care. We use single-cell assays to assess HbF, HbS, oxygen saturation, and hemoglobin polymer content in RBCs for nine gene therapy trial subjects (BCLshmiR, median HbF% = 27.9) and compare them to 10 HU-treated subjects demonstrating high and comparable levels of HbF (HU High Responders, median HbF% = 27.0). All BCL11A patients achieved the primary endpoint for NCT 03282656, which was defined by an absolute neutrophil count greater than or equal to 0.5 × 109 cells/L for three consecutive days, achieved within 7 weeks following infusion. Flow cytometric assessment of single-RBC HbF and HbS shows fewer RBCs with high HbS% that would be most susceptible to sickling in BCLshmiR vs. HU High Responders: median 42% of RBCs with HbS%>70% in BCLshmiR vs. 61% in HU High Responders (p = 0.004). BCLshmiR subjects also demonstrate more RBCs resistant to HbS polymerization at lower physiologic oxygen tension: median 32% vs. 25% in HU High Responders (p = 0.006). Gene therapy-induced BCL11A down-regulation reverses the fetal-to-adult hemoglobin switch and induces RBCs with higher HbF%, lower HbS%, and greater resistance to deoxygenation-induced polymerization in clinical trial subjects compared with a cohort of highly responsive hydroxyurea-treated subjects

Synthèse et étude des propriétés de nanoparticules magnétiques de type cœur-coquille.

The bimetallic magnetic nanoparticles (NPs) of core-shell type exhibit a huge potential of application due to the wide range of properties available for this type of objects. Each potential application requires particles of specific optimised properties which needs on the one hand, the development of synthesis methods and on the other, a thorough study of their properties. In this thesis we have developed methods allowing the direct synthesis of 3d/4d NPs (here Fe/Rh) of core-shell 3d@4d and 4d@3d type by reversing the kinetics of reduction of the 3d and 4d elements precursors. The Rh atoms production is faster under dihydrogène and those of Fe atoms in the presence of amine borane. For this system, which combines a magnetic metal (Fe) and a magnetic polarisable one (Rh) we were able to study the influence of the chemical order and of the structure (evidenced by WAXS , XANES and EXAFS) on the magnetic properties through measures SQUID, Mössbauer and XMCD. In the second part we have developed the synthesis of CoAl alloy and used the higher reactivity of aluminium towards the oxygen to cause the segregation of Co and the formation of alumina in order to obtain in fine systems of Co@Al2O3 type. This segregation was followed by magnetic measurements.Les nanoparticules (NPs) bimétalliques magnétiques de type cœur-coquille présentent un énorme potentiel d'application dû à l'éventail de propriétés envisageables pour ce type d'objets. Chaque application requiert des particules aux propriétés optimisées spécifiques ce qui nécessite d'une part le développement de méthodes de synthèse et d'autre part une étude approfondie de leurs propriétés. Au cours de cette thèse nous avons mis au point des méthodes de synthèse permettant l'obtention directe de NPs 3d/4d (ici Fe/Rh) de type cœur-coquille 3d@4d ou 4d@3d en renversant les cinétiques de réduction des précurseurs des éléments 3d ou 4d. Ainsi, sous dihydrogène, les atomes de rhodium sont engendrés plus rapidement que ceux de Fe (formation de NPs Rh@Fe) alors que le contraire est observé en présence de complexe amine-borane (d'où la formation de NPs Fe@Rh). Sur ce système qui combine un métal magnétique (Fe) et un métal magnifiquement polarisable (Rh) nous avons pu étudier l'influence de l'ordre chimique et de la structure (sondés par WAXS, EXAFS et XANES) sur les propriétés magnétiques des NPs par des mesures couplées SQUID, Mössbauer et XMCD. Nous avons dans un deuxième temps développé la synthèse de NPs d'alliage CoAl et utilisé la plus forte réactivité de l'aluminium vis-à-vis du dioxygène pour engendrer la ségrégation du Co et la formation d'alumine dans le but d'obtenir in fine de systèmes Co@Al2O3. Cette ségrégation a été suivie par des mesures d'aimantation au SQUID

Synthèse et étude des propriétés de nanoparticules magnétiques de type coeur-coquille

TOULOUSE3-BU Sciences (315552104) / SudocSudocFranceF

Easy colorimetric detection of gadolinium ions based on gold nanoparticles: key role of phosphine-sulfonate ligands

International audienceThe possibility to easily and rapidly assess the presence of Gd 3+ ions in solution is of paramount importance in many domains like magnetic resonance imaging. In that context, the use of easy to implement colorimetric sensing probes based on gold nanoparticles (AuNPs) is of special interest. Herein, AuNPs functionalized with a commercial bis(p-sulfonatophenyl)phenyl phosphine ligand (BSPP) (AuNP@BSPP), bearing negatively charged sulfonate groups are used as a colorimetric sensing probe. The addition of Gd 3+ ions onto these NPs was studied through UV-visible absorbance measurements, Quartz Crystal Microbalance with Dissipation monitoring (QCM-D) and transmission electron microscopy and compared with citrate covered AuNPs. We evidenced interactions between the Gd 3+ ions and their water rich coordination sphere and sulfonate groups on the surface of AuNP@BSPP via electrostatic interactions and hydrogen bonding. These interactions induce the reversible aggregation of AuNP@BSPP in the presence of concentrations of Gd 3+ ions at a mM level. We took advantage of this phenomenon to develop a simple and fast bench colorimetric assay for the detection of free Gd 3+ ions, based on the determination of a flocculation parameter thanks to UV-visible measurements. Limits of detection and quantification were found equal to 0.74 mM and 4.76 mM of Gd 3+ ions, respectively, with a high sensitivity that competes with conventional methods used for lanthanide detection