Noncanonical Biogenesis of Centrioles and Basal Bodies

The deposited article is a pre-print version.The deposited article version is the Epub Ahead of Print version of the article, posted online 23 April 2018, provided by Cold Spring Harbor Laboratory Press. It hasn't peer-review.This deposit is composed by the main article, and it hasn't any supplementary materials associated.Centrioles and basal bodies (CBBs) organize centrosomes and cilia within eukaryotic cells. These organelles are composed of microtubules and hundreds of proteins performing multiple functions such as signaling, cytoskeleton remodeling, and cell motility. The CBB is present in all branches of the eukaryotic tree of life and, despite its ultrastructural and protein conservation, there is diversity in its function, occurrence (i.e., presence/absence), and modes of biogenesis across species. In this review, we provide an overview of the multiple pathways through which CBBs are formed in nature, with a special focus on the less studied, noncanonical ways. Despite the differences among each mechanism herein presented, we highlighted some of their common principles. These principles, governing different steps of biogenesis, ensure that CBBs may perform a multitude of functions in a huge diversity of organisms but yet retained their robustness in structure throughout evolution.European Research Council Consolidator Grant: (CoG683528__Centriole-BirthDeath); Boehringer Ingelheim Fonds; Fundação para a Ciência e Tecnologia grant: (PD/BD/114350/2016).info:eu-repo/semantics/acceptedVersio

Birep: a reputation scheme to mitigate the effects of black-hole nodes in delay-tolerant internet of vehicles

Delay-tolerant networking (DTN) enables communication in disruptive scenarios where issues such as sparse and intermittent connectivity, long and variable delays, high latency, high error rates, or no end-to-end connectivity exist. Internet of Vehicles (IoV) is a network of the future in which integration between devices, vehicles, and users will be unlimited and universal, overcoming the heterogeneity of systems, services, applications, and devices. Delay-tolerant internet of vehicles (DT-IoV) is emerging and becoming a popular research topic due to the critical applications that can be realized, such as software or map update dissemination. For an IoV to work efficiently, a degree of cooperation between nodes is necessary to deliver messages to their destinations. However, nodes might misbehave and silently drop messages, also known as a black-hole attack, degrading network performance. Various solutions have been proposed to deal with black-hole nodes, but most are centralized or require each node to meet every other node. This paper proposes a decentralized reputation scheme called BiRep that identifies and punishes black-hole nodes in DT-IoV. BiRep is tested on the Prophet routing protocol. Simulation results show excellent performance in all scenarios, comparable or better to other reputation schemes, significantly increasing the delivery ratio of messages

Interphase chemistry of Si electrodes used as anodes in Li-ion batteries

International audienceThe effect of the Si electrode morphology (amorphous hydrogenated silicon thin films - a-Si:H as a model electrode and Si nanowires - SiNWs electrode) on the interphase chemistry was thoroughly investigated by the surface science techniques: X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). XPS analysis shows a strong attenuation and positive shift of the Si 2p peaks after a complete charge/discharge performed in PC- and EC:DMC-based electrolytes for both electrodes (a-Si:H and SiNW), confirming a formation of a passive film (called solid electrolyte interphase - SEI layer). As evidenced from the XPS analysis performed on the model electrode, the thicker SEI layer was formed after cycling in PC-based electrolyte as compared to EC:DMC electrolyte. XPS and ToF-SIMS investigations reveal the presence of organic carbonate species on the outer surface and inorganic salt decomposition species in the inner part of the SEI layer. Significant modification of the surface morphol- ogy for the both electrodes and a full surface coverage by the SEI layer was confirmed by the scanning electron microscopy (SEM) analysis

332 Predictors and prognostic value of contrast-induced nephropathy in patients undergoing primary angioplasty

PurposeContrast-induced nephropathy (CIN) after coronariography has been associated to increased morbidity and mortality. Patients submitted to primary angioplasty seem to be at higher risk for CIN development, owing in part to hemodynamic status. We sought to determine the prevalence, predictors and prognostic value of CIN occurrence after primary angioplasty.MethodsA total of 141 patients consecutively submitted to primary angioplasty and admitted to our coronary unit were reviewed. CIN was defined as impairment of renal function occurring within 48 hours after administration of contrast media and manifested by an absolute increase in the serum creatinine level of at least 0.5mg/dl or by a relative increase of at least 25% over the baseline value (in the absence of another cause). The primary end points were in-hospital and six-month mortality.ResultsCIN developed in 18.4% of the patients (n=26). Patients with CIN were older (68±13 vs 61±13 years; p<0.05) and more often had diabetes mellitus (38.5% vs 15.7%; p<0.05). Although statistical significance was not reached, there was a trend for higher prevalence of hypertension (61.5% vs 42.6%; p=0.09), female gender (30.8% vs 18.3%; p=0.18) and Killip class higher than one at admission (26.9% vs 16.3%; p=0.1) among patients with CIN. Patients with CIN had an higher mean time from symptoms to reperfusion (304±192 vs 397±206 minutes; p<0.04). By multivariate analysis, independent correlates of CIN were older age (OR=1.04; 95%CI=1.01 − 1.08) and diabetes mellitus (OR=2.99; 95%CI=1.08 − 8.3). Patients with CIN had higher in-hospital (19.2% vs 0.9%; p<0.05) and 6-month mortality (28.6% vs 4.9%; p<0.05).ConclusionsCIN was a frequent complication of primary angioplasty (18.4% of the patients). Independent predictors of CIN after primary angioplasty were older age and diabetes mellitus. Patients with CIN had a worse prognosis, both during in-hospital stay and at 6 months

Contribution to the study of lithium electrochemical insertion in graphite / Pb and graphite / Sn / Sb nanocomposites

Cette étude s’inscrit dans le cadre de la recherche de nouvelles électrodes négatives de batteries à ions lithium ayant des capacités supérieures à celles du graphite. La synthèse de nouveaux matériaux d’électrode, constitués de nanoparticules métalliques de plomb ou d’alliage étain/antimoine déposées sur le graphite, consiste à réduire des halogénures métalliques, en présence de graphite, à l’aide d’un hydrure alcalin (NaH ou LiH) activé par un alcoolate généré in situ. Les caractéristiques structurales et morphologiques des différents systèmes graphite – métal sont ici étudiées par DRX, MET et MEB afin de mieux comprendre les mécanismes susceptibles d’intervenir lors de l’insertion de lithium. Le système graphite - plomb est étudié dans le but d’appréhender l’importance des interactions graphite - métal sur les performances électrochimiques. En effet, le caractère métallique du plomb paraît conduire à un faible ancrage des nanoparticules au support carboné et à des performances médiocres de ces matériaux comme électrodes négatives de batteries Li-ion. L’investigation systématique des composites graphite/(1-x)Sn/(x)Sb en fonction de la teneur en antimoine montre que le caractère semi-métallique de l’antimoine conduit à une amélioration des propriétés mécaniques et d’ancrage des nanoparticules de l’alliage SnSb au graphite. L’étude structurale et morphologique en fonction de la nature de l’hydrure montre que LiH comparé à NaH conduit à des composites plus homogènes, dont les particules, mieux accrochées à la surface du graphite, présentent une meilleure tenue en cyclage et des capacités massiques plus élevées.The main propose of this work is to investigate new anode materials possessing high mass capacity and being able of replacing graphite in Li-ion batteries. Electrode materials constituted of Pb and Sn/Sb alloy nanoparticles dispersed on the graphite surface, were obtained by chemical reduction of a metal halide, in the presence of graphite, using an alkoxide - activated hydride (NaH or LiH) as a reducing agent. To collect information about the structural and the morphological characteristics of graphite-metal powders, XRD, TEM and SEM analyses were performed. These results allowed to establish a relation between the powder sample characteristics and the encountered electrochemical performances (mass capacity and cycling stability) during lithium insertion / de-insertion process. Graphite – Pb system was used as model for studying the influence of metal-graphite interactions on the electrochemical behaviour of graphite-metal compounds. The results point out to a weak interaction between Pb metal particles and the graphite surface, which seems to be the main reason for the poor electrochemical performances observed during cycling. The systematic study of graphite/(1-x)Sn/(x)Sb composites as function of Sb content appears to show that antimony semi-metallic character is responsible for SnSb pinning on the graphite surface and improvement of their electrochemical properties. Structural and morphological studies have also shown that hydride nature influences sample homogeneity, since LiH, compared to NaH, conducts to an uniform dispersion of the anchored nanoparticles on the graphite surface and to an higher mass capacity retention and stability upon cycling

Contribution à l’étude de l’insertion électrochimique du lithium dans des nanocomposites graphite/Pb et graphite/Sn/Sb

The main propose of this work is to investigate new anode materials possessing high mass capacity and being able of replacing graphite in Li-ion batteries. Electrode materials constituted of Pb and Sn/Sb alloy nanoparticles dispersed on the graphite surface, were obtained by chemical reduction of a metal halide, in the presence of graphite, using an alkoxide - activated hydride (NaH or LiH) as a reducing agent. To collect information about the structural and the morphological characteristics of graphite-metal powders, XRD, TEM and SEM analyses were performed. These results allowed to establish a relation between the powder sample characteristics and the encountered electrochemical performances (mass capacity and cycling stability) during lithium insertion / de-insertion process. Graphite – Pb system was used as model for studying the influence of metal-graphite interactions on the electrochemical behaviour of graphite-metal compounds. The results point out to a weak interaction between Pb metal particles and the graphite surface, which seems to be the main reason for the poor electrochemical performances observed during cycling. The systematic study of graphite/(1-x)Sn/(x)Sb composites as function of Sb content appears to show that antimony semi-metallic character is responsible for SnSb pinning on the graphite surface and improvement of their electrochemical properties. Structural and morphological studies have also shown that hydride nature influences sample homogeneity, since LiH, compared to NaH, conducts to an uniform dispersion of the anchored nanoparticles on the graphite surface and to an higher mass capacity retention and stability upon cycling.Cette étude s’inscrit dans le cadre de la recherche de nouvelles électrodes négatives de batteries à ions lithium ayant des capacités supérieures à celles du graphite. La synthèse de nouveaux matériaux d’électrode, constitués de nanoparticules métalliques de plomb ou d’alliage étain/antimoine déposées sur le graphite, consiste à réduire des halogénures métalliques, en présence de graphite, à l’aide d’un hydrure alcalin (NaH ou LiH) activé par un alcoolate généré in situ. Les caractéristiques structurales et morphologiques des différents systèmes graphite – métal sont ici étudiées par DRX, MET et MEB afin de mieux comprendre les mécanismes susceptibles d’intervenir lors de l’insertion de lithium. Le système graphite - plomb est étudié dans le but d’appréhender l’importance des interactions graphite - métal sur les performances électrochimiques. En effet, le caractère métallique du plomb paraît conduire à un faible ancrage des nanoparticules au support carboné et à des performances médiocres de ces matériaux comme électrodes négatives de batteries Li-ion. L’investigation systématique des composites graphite/(1-x)Sn/(x)Sb en fonction de la teneur en antimoine montre que le caractère semi-métallique de l’antimoine conduit à une amélioration des propriétés mécaniques et d’ancrage des nanoparticules de l’alliage SnSb au graphite. L’étude structurale et morphologique en fonction de la nature de l’hydrure montre que LiH comparé à NaH conduit à des composites plus homogènes, dont les particules, mieux accrochées à la surface du graphite, présentent une meilleure tenue en cyclage et des capacités massiques plus élevées

Diaminoethane adsorption and water substitution on hydrated TiO2: a thermochemical study based on first-principles calculations

International audienceEpoxy-amines are used as structural adhesives deposited on Ti. The amine adhesion to a Ti surface depends highly on the surface state (oxidation, hydroxylation). Amines may adsorb above preadsorbed water molecules or substitute them to bind directly to surface Ti4+ Lewis acid sites. The adsorption of a model amine molecule, diaminoethane (DAE), on a model surface, hydrated TiO2-anatase (101) surface, is investigated using Density Functional Theory including Dispersive forces (DFT-D) calculations. DAE adsorption and water substitution by DAE are exothermic processes and turn nearly isoenergetic at high coverage with adsorption–substitution energies around −0.3 eV (including dispersion forces and ZPE). Complementary ab initio molecular dynamics studies also suggest that the formation of an amine–water interaction induces water desorption from the surface at room temperature, a preliminary step towards the amine–Ti bond formation. An atomistic thermodynamic approach is developed to evaluate the interfacial free energy balance of both processes (adsorption and substitution). The main contributions to the energetic balance are dispersive interactions between molecules and the surface on the exergonic side, translational and rotational entropic contributions on the endergonic one. The substitution process is stabilized by 0.55 eV versus the adsorption one when free solvation, rotational and vibrational energies are considered. The main contribution to this free energy gain is due to water solvation. The calculations suggest that in toluene solvent with a water concentration of 10−4 M or less, a full DAE layer replaces a preadsorbed water layer for a threshold concentration of DAE ≥ 0.1 M