Hybrid hierarchical patterns of gold nanoparticles and poly(ethylene glycol) microstructures

Hybrid surface micro-patterns composed of topographic structures of polyethylene glycol (PEG)-hydrogels and hierarchical lines of gold nanoparticles (Au NPs) were fabricated on silicon wafers. Micro-sized lines of Au NPs were first obtained on the surface of a silicon wafer via “micro-contact deprinting”, a method recently developed by our group. Topographic micro-patterns of PEG, of both low and high aspect ratio (AR up to 6), were then aligned on the pre-patterned surface via a procedure adapted from the soft lithographic method MIMIC (Micro-Molding in Capillaries), which is denoted as “adhesive embossing”. The result is a complex surface pattern consisting of alternating flat Au NP lines and thick PEG bars. Such patterns provide novel model surfaces for elucidating the interplay between (bio)chemical and physical cues on cell behavior

In Situ Formed “Sn1–XInX@In1–YSnYOZ” Core@Shell Nanoparticles as Electrocatalysts for CO2 Reduction to Formate

Electrochemical reduction of CO2 (CO2RR) driven by renewable energy has gained increasing attention for sustainable production of chemicals and fuels. Catalyst design to overcome large overpotentials and poor product selectivity remains however challenging. Sn/SnOx and In/InOx composites have been reported active for CO2RR with high selectivity toward formate formation. In this work, the CO2RR activity and selectivity of metal/metal oxide composite nanoparticles formed by in situ reduction of bimetallic amorphous SnInOx thin films are investigated. It is shown that during CO2RR the amorphous SnInOx pre‐catalyst thin films are reduced in situ into Sn1–XInX@In1–YSnYOz core@shell nanoparticles composed of Sn‐rich SnIn alloy nanocores (with x < 0.2) surrounded by InOx‐rich bimetallic InSnOx shells (with 0.3 < y < 0.4 and z ≈ 1). The in situ formed particles catalyze the CO2RR to formate with high faradaic efficiency (80%) and outstanding formate mass activity (437 A gIn+Sn−1 @ −1.0 V vs RHE in 0.1 m KHCO3). While extensive structural investigation during CO2RR reveals pronounced dynamics in terms of particle size, the core@shell structure is observed for the different electrolysis conditions essayed, with high surface oxide contents favoring formate over hydrogen selectivity.DFG, 53182490, EXC 314: Unifying Concepts in CatalysisBMBF, 03X5524, EDELKAT - Hydrophobe Nanoreaktor Templatierung - Eine Tool-Box für optimierte ElektrokatalysatorenBMBF, 01FP13033F, Förderung der Vorgriffsprofessur im Fach "Anorganische Funktionsmaterialien" im Rahmen des Professorinnenprogramms II an der Albert-Ludwigs-Universität FreiburgEC/H2020/101006701/EU/Renewable Electricity-based, cyclic and economic production of Fuel/EcoFue

Sheldon Spectrum and the Plankton Paradox: Two Sides of the Same Coin : A trait-based plankton size-spectrum model

The Sheldon spectrum describes a remarkable regularity in aquatic ecosystems: the biomass density as a function of logarithmic body mass is approximately constant over many orders of magnitude. While size-spectrum models have explained this phenomenon for assemblages of multicellular organisms, this paper introduces a species-resolved size-spectrum model to explain the phenomenon in unicellular plankton. A Sheldon spectrum spanning the cell-size range of unicellular plankton necessarily consists of a large number of coexisting species covering a wide range of characteristic sizes. The coexistence of many phytoplankton species feeding on a small number of resources is known as the Paradox of the Plankton. Our model resolves the paradox by showing that coexistence is facilitated by the allometric scaling of four physiological rates. Two of the allometries have empirical support, the remaining two emerge from predator-prey interactions exactly when the abundances follow a Sheldon spectrum. Our plankton model is a scale-invariant trait-based size-spectrum model: it describes the abundance of phyto- and zooplankton cells as a function of both size and species trait (the maximal size before cell division). It incorporates growth due to resource consumption and predation on smaller cells, death due to predation, and a flexible cell division process. We give analytic solutions at steady state for both the within-species size distributions and the relative abundances across species

L-Plastin nanobodies perturb matrix degradation, podosome formation, stability and lifetime in THP-1 macrophages

Podosomes are cellular structures acting as degradation ‘hot-spots’ in monocytic cells. They appear as dot-like structures at the ventral cell surface, enriched in F-actin and actin regulators, including gelsolin and L-plastin. Gelsolin is an ubiquitous severing and capping protein, whereas L-plastin is a leukocyte-specific actin bundling protein. The presence of the capping protein CapG in podosomes has not yet been investigated. We used an innovative approach to investigate the role of these proteins in macrophage podosomes by means of nanobodies or Camelid single domain antibodies. Nanobodies directed against distinct domains of gelsolin, L-plastin or CapG were stably expressed in macrophage-like THP-1 cells. CapG was not enriched in podosomes. Gelsolin nanobodies had no effect on podosome formation or function but proved very effective in tracing distinct gelsolin populations. One gelsolin nanobody specifically targets actin-bound gelsolin and was effectively enriched in podosomes. A gelsolin nanobody that blocks gelsolin-G-actin interaction was not enriched in podosomes demonstrating that the calcium-activated and actin-bound conformation of gelsolin is a constituent of podosomes. THP-1 cells expressing inhibitory L-plastin nanobodies were hampered in their ability to form stable podosomes. Nanobodies did not perturb Ser5 phosphorylation of L-plastin although phosphorylated L-plastin was highly enriched in podosomes. Furthermore, nanobody-induced inhibition of L-plastin function gave rise to an irregular and unstable actin turnover of podosomes, resulting in diminished degradation of the underlying matrix. Altogether these results indicate that L-plastin is indispensable for podosome formation and function in macrophages

Tuberculosis is associated with expansion of a motile, permissive and immunomodulatory CD16(+) monocyte population via the IL-10/STAT3 axis

The human CD14+ monocyte compartment is composed by two subsets based on CD16 expression. We previously reported that this compartment is perturbed in tuberculosis (TB) patients, as reflected by the expansion of CD16+ monocytes along with disease severity. Whether this unbalance is beneficial or detrimental to host defense remains to be elucidated. Here in the context of active TB, we demonstrate that human monocytes are predisposed to differentiate towards an anti-inflammatory (M2-like) macrophage activation program characterized by theCD16+CD163+MerTK+pSTAT3+ phenotype and functional properties such as enhanced protease-dependent motility, pathogen permissivity and immunomodulation. This process is dependent on STAT3 activation, and loss-of-function experiments point towards a detrimental role in host defense against TB. Importantly, we provide a critical correlation between the abundance of the CD16+CD163+MerTK+pSTAT3+ cells and the progression of the disease either at the local level in a non-human primate tuberculous granuloma context, or at the systemic level through the detection of the soluble form of CD163 in human sera. Collectively, this study argues for the pathogenic role of the CD16+CD163+MerTK+pSTAT3+ monocyte-to-macrophage differentiation program and its potential as a target for TB therapy,and promotes the detection of circulating CD163 as a potential biomarker for disease progression and monitoringof treatment efficacy.Fil: Lastrucci, Claire. Centre National de la Recherche Scientifique; FranciaFil: Bénard, Alan. Centre National de la Recherche Scientifique; FranciaFil: Balboa, Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Pingris, Karine. Centre National de la Recherche Scientifique; FranciaFil: Souriant, Shanti. Centre National de la Recherche Scientifique; FranciaFil: Poincloux, Renaud. Centre National de la Recherche Scientifique; FranciaFil: Al Saati, Talal. Inserm; FranciaFil: Rasolofo, Voahangy. Pasteur Institute in Antananarivo; MadagascarFil: González Montaner, Pablo. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas ; ArgentinaFil: Inwentarz, Sandra. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas ; ArgentinaFil: Moraña, Eduardo José. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas ; ArgentinaFil: Kondova, Ivanela. Biomedical Primate Research Centre; Países BajosFil: Verreck, Franck A. W.. Biomedical Primate Research Centre; Países BajosFil: Sasiain, María del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Neyrolles, Olivier. Centre National de la Recherche Scientifique; FranciaFil: Maridonneau Parini, Isabel. Centre National de la Recherche Scientifique; FranciaFil: Lugo Villarino, Geanncarlo. Centre National de la Recherche Scientifique; FranciaFil: Cougoule, Celine. Centre National de la Recherche Scientifique; Franci

Dome patterns in pelagic size spectra reveal strong trophic cascades

In ecological communities, especially the pelagic zones of aquatic ecosystems, certain bodysize ranges are often over-represented compared to others. Community size spectra, the distributions of community biomass over the logarithmic body-mass axis, tend to exhibit regularly spaced local maxima, called "domes", separated by steep troughs. Contrasting established theory, we explain these dome patterns as manifestations of top-down trophic cascades along aquatic food chains. Compiling high quality size-spectrum data and comparing these with a size-spectrum model introduced in this study, we test this theory and develop a detailed picture of the mechanisms by which bottom-up and top-down effects interact to generate dome patterns. Results imply that strong top-down trophic cascades are common in freshwater communities, much more than hitherto demonstrated, and may arise in nutrient rich marine systems as well. Transferring insights from the general theory of nonlinear pattern formation to domes patterns, we provide new interpretations of past lake-manipulation experiments

VI - Le système informatique de conduite

Le groupement CERCI/CIMSA-SINTRA s'est vu confier par EDF l'étude et la réalisation du système informatique de conduite (KIC) des tranches du palier N4. Après avoir rappelé les principaux objectifs visés, les auteurs présentent l'architecture du KIC, les solutions logicielles retenues et les chiffres-clé essentiels du système