Phase‐Dependent Long Persistent Phosphorescence in Coumarin‐Phosphine‐Based Coinage Metal Complexes

A coumarin functionalized aminodiphosphine has been introduced as a bidentate ligand in coinage metal chemistry. Mono-, di-, and trimetallic copper and silver complexes were synthesized with this ligand. The hybrid character of the ligand led to compounds with rich luminescence properties. These include coumarin-based blue fluorescence, observed as a sole emission in solution at room temperature, and green phosphorescence, which is efficient at low temperatures and dominates the spectra of the metal complexes. In the rigid environment of frozen solutions, the green phosphorescence shows an unusually long (for metal complexes) decay on the seconds timescale in high quantum yield. In addition, a red phosphorescence, which may be assigned to the triplet state localized in the phosphine-M$_{3}$Cl$_{2}$ (M=Cu, Ag), is observed for the trinuclear complexes at low temperature. Neither the second-long phosphorescence nor the red emission is observed for the coumarin ligand, thus they must be a result of the coordination to coinage metal clusters. The excited states in these compounds were also investigated by femtosecond transient absorption spectroscopy and quantum chemical calculations

Two Antagonistic MALT1 Auto-Cleavage Mechanisms Reveal a Role for TRAF6 to Unleash MALT1 Activation.

The paracaspase MALT1 has arginine-directed proteolytic activity triggered by engagement of immune receptors. Recruitment of MALT1 into activation complexes is required for MALT1 proteolytic function. Here, co-expression of MALT1 in HEK293 cells, either with activated CARD11 and BCL10 or with TRAF6, was used to explore the mechanism of MALT1 activation at the molecular level. This work identified a prominent self-cleavage site of MALT1 isoform A (MALT1A) at R781 (R770 in MALT1B) and revealed that TRAF6 can activate MALT1 independently of the CBM. Intramolecular cleavage at R781/R770 removes a C-terminal TRAF6-binding site in both MALT1 isoforms, leaving MALT1B devoid of the two key interaction sites with TRAF6. A previously identified auto-proteolysis site of MALT1 at R149 leads to deletion of the death-domain, thereby abolishing interaction with BCL10. By using MALT1 isoforms and cleaved fragments thereof, as well as TRAF6 WT and mutant forms, this work shows that TRAF6 induces N-terminal auto-proteolytic cleavage of MALT1 at R149 and accelerates MALT1 protein turnover. The MALT1 fragment generated by N-terminal self-cleavage at R149 was labile and displayed enhanced signaling properties that required an intact K644 residue, previously shown to be a site for mono-ubiquitination of MALT1. Conversely, C-terminal self-cleavage at R781/R770 hampered the ability for self-cleavage at R149 and stabilized MALT1 by hindering interaction with TRAF6. C-terminal self-cleavage had limited impact on MALT1A but severely reduced MALT1B proteolytic and signaling functions. It also abrogated NF-κB activation by N-terminally cleaved MALT1A. Altogether, this study provides further insights into mechanisms that regulate the scaffolding and activation cycle of MALT1. It also emphasizes the reduced functional capacity of MALT1B as compared to MALT1A

Imagerie Doppler temps réel

Les méthodes permettant d'évaluer l'importance d'une sténose sont essentiellement l'échographie bidimensionnelle et la vélocimètrie Doppler. L'analyse du signal Doppler peut se faire soit à partir d'un vélocimètre à émission continue qui permet une mesure globale des vitesses rencontrées dans le champ ultra-sonore, soit à partir d'un vélocimètre à émission codée qui permet de sélectionner le volume de mesure et par voie de conséquence de tracer des profils de vitesse. Aucun ne permet de visualiser un segment de vaisseau. Les limitations de ces deux méthodes sont en partie éliminées par l'emploi simultané d'un imageur et par l'analyse spectrale du signal Doppler. L'imagerie bidimensionnelle donne essentiellement la géométrie des parois artérielles et l'aspect obtenu est souvent le même que l'artère soit vide d'écho ou obstruée par un caillot frais. Pour s'affranchir de ce problème deux voies sont proposées : soit associer un échographe bidimensionnel avec un vélocimètre Doppler, ce sont les systèmes duplex, soit développer des imageurs Doppler temps réel permettant de faire une image d'un segment de vaisseau. Déjà plusieurs propositions et réalisations ont été faites. Les images n'étant pas obtenues en temps réel, ces propositions ont eu un succès modeste. Il faut environ 20 à 60 minutes pour l'exploration bilatérale des carotides. Nous proposons un système à barrette composé de n couples de transducteurs émetteurs et récepteurs. Chaque couple est connecté à un vélocimètre à émission continue dont la fréquence d'émission diffère pour chaque voie. Cette possibilité permet d'émettre simultanément dans n directions et par là-même de recueillir simultanément autant d'information de vitesses qu'il y a de voies. L'interaction parasite entre les différentes voies a été éliminée par un filtre passe-haut du Sème ordre. Nous montrons les résultats obtenus sur un prototype à trois voies d'abord sur un fil défilant puis sur un tuyau où une sténose est simulée. Enfin un résultat in vivo laisse à penser que cette solution est prometteuse

Parametric methods for automatic evaluation of bubble grade in blood

Bubble detection in blood of divers during decompression has been studied for a long time, but is still unperfectly resolved . Generally, an ultrasonic Doppler probe is used to provide an acoustic signal, winch can be aurally analysed by a human expert to estimate bubble grade . Automatic detection has given only specific results so far, )vithout generalization capabilities. This paper describes a multi-criterion mathernatical approach covering spatial and spectral information of the signal. The acquisition of one hundred bubble grade evaluated signais allowed us ta use statistical methods such as data analysis, in order to obtain adaptive real-time procedures. A multilayer perceptron has been simulated and iested to salve the bubble grade discrimination problem .La détection des bulles dans le sang des plongeurs en phase de décompression est un problème qui a fait l'objet de très nombreuses études, mais est encore imparfaitement résolu. On utilise généralement une sonde ultrasonore Doppler fournissant un signal sonore complexe, que l'expert humain est le seul actuellement à pouvoir analyser correctement grâce à l'écoute directe ou différée. La détection automatique n'a en effet donné pour l'instant que des résultats trop spécifiques et difficilement généralisables. On a envisagé ici une approche mathématique multi-critères intégrant l'information temporelle et spectrale de signaux dont le produit BT est faibl

Ultrafast photoinduced dynamics of halogenated cyclopentadienes: Observation of geminate charge-transfer complexes in solution

The photoinduced dynamics of the fully halogenated cyclopentadienes C 5Cl6 and C5Br6 have been investigated in solution and gas phase by femtosecond time-resolved spectroscopy. Both in solution and in gas phase, homolytic dissociation into a halogen radical and a C5X5 (X = Cl, Br) radical was observed. In liquid phase, solvent-dependent formation of charge transfer complexes between geminate radicals was observed for the first time. These complexes were found to be surprisingly stable and offered the opportunity to follow the dynamics of specific radical pairs. In the case of C 5Cl6 in trichloroethanol, a reaction of the chlorine radical with molecules from the solvent cage was observed. \ua9 2013 the Owner Societies.Peer reviewed: YesNRC publication: Ye

Introduction: Integration as a Three-Way Process Approach?

This chapter introduces the topic of this volume, which is the recent departure from viewing integration as a strictly two-way process (between migrants and the receiving society) to acknowledge the potential role that countries of origin might play in support of the integration process. It traces the origin of this change in policy perspective, reviewing the Europeanization of immigration and integration policy since the Tampere Programme (1999–2004). Indeed, a major shift in policy framing came in 2011, with the renewed European Agenda for the Integration of Third-Country Nationals, which explicitly added the countries of origin as a third key actor in the process of immigrants’ integration, thereby introducing the three-way process in European policy. In addition to tracing the development of European policy on integration, it takes a step back to consider three broad and interconnected issues: (i) the way integration is conceptualized and studied in Europe; (ii) the way integration policies are studied and how the concept of integration is used in policy formulation and practice; and (iii) the way new perspectives and actors (e.g., those in countries of origin) are incorporated in analyses of integration processes and policies. It concludes by introducing the further structure of the volume