Comparative analysis of conjugated alkynyl chromophore-triazacyclononane ligands for sensitized emission of europium and terbium

A series of europium and terbium complexes based on a functionalized triazacyclononane carboxylate or phosphinate macrocyclic ligand is described. The influence of the anionic group, that is, carboxylate, methylphosphinate, or phenylphosphinate, on the photophysical properties was studied and rationalized on the basis of DFT calculated structures. The nature, number, and position of electron-donating or electron-withdrawing aryl substituents were varied systematically within the same phenylethynyl scaffold in order to optimize the brightness of the corresponding europium complexes and investigate their two-photon absorption properties. Finally, the europium complexes were examined in cell-imaging applications, and selected terbium complexes were studied as potential oxygen sensors

Fluorescent organic ion pairs based on berberine: counter-ion effect on the formation of particles and on the uptake by colon cancer cells

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A comparative study of nine berberine salts in the solid state: optimization of the photoluminescence and self-association properties through the choice of the anion

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Small Iminocoumarin Derivatives as Red Emitters: From Biological Imaging to Highly Photoluminescent Non-doped Micro- and Nanofibres

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Synthesis, Characterization, and Self-Assembling Properties of New Amphiphilic Dendrons Bearing Branched TRIS-Derived Oligomers as Polar Head Groups

International audienceThe synthesis and characterization of a new familyof dendritic surfactants called DendriTAC are described. Twoseries of single- or double-tailed surfactants containing hydrophobichydrocarbon or fluorocarbon chains grafted onto Tris-(hydroxymethyl)aminomethane (or TRIS)-derived oligomericpolar heads via a copper(I)-mediated click reaction have beenprepared. A total of 13 new dendritic surfactants have beenobtained by grafting linear polyTRIS branches of variable averagedegree of polymerization (DPn) onto a single or double-tailedfluorinated or hydrocarbon chain of variable length, via a dendriticcentral scaffold of generation G1 or G2. Structural parameters of thesurfactant assemblies in solution [radii of gyration (RG), volumeweightedhydrodynamic radii (RH), and aggregation numbers(Nag)] were assessed by small-angle X-ray scattering and dynamic light scattering. Overall, regardless of their tree-like structure (i.e.,generation type), length of the headgroup (DPn), and nature (hydrocarbonated or fluorinated, single or double-tail) or length of thehydrophobic chains, self-assembling properties of H/F-DendriTACs are in agreement with usual trends of surfactant assemblies, e.g.,as a function of chain length or polar head volume. Thus, thanks to their great structural versatility, H/F-DendriTACs can providehighly tunable self-assembly morphologies that can be adapted to specific applications

Zwitterionic fluorinated detergents: From design to membrane protein applications.

International audienceWe report herein the synthesis of zwitterionic sulfobetaine (SB) and dimethylamine oxide (AO) detergents whose alkyl chain is made of either a perfluorohexyl (F6H3) or a perfluoropentyl (F5H5) group linked to a hydrogenated spacer arm. In aqueous solution, the critical micellar concentrations (CMCs) measured by surface tensiometry (SFT) and isothermal titration calorimetry (ITC) were found in the millimolar range (1.3-2.4 mM). The morphologies of the aggregates were evaluated by dynamic light scattering (DLS), analytical ultracentrifugation (AUC), small-angle X-ray scattering (SAXS), and transmission electron microscopy (TEM), demonstrating that the two perfluoropentyl derivatives formed small micelles less than 10 nm in diameter, whereas the perfluorohexyl derivatives formed larger and more heterogeneous micelles. The two SB detergents were able to solubilize synthetic lipid vesicles in a few hours; by contrast, the perfluoropentyl AO induced much faster solubilization, whereas the perfluorohexyl AO did not show any solubilization. All detergents were tested for their abilities to stabilize three membrane proteins, namely, bacteriorhodopsin (bR), the Bacillus subtilis ABC transporter BmrA, and the Streptococcus pneumoniae enzyme SpNOX. The SB detergents outperformed the AO derivatives as well as their hydrogenated analogs in stabilizing these proteins. Among the four new compounds, F5H5SB combines many desirable properties for membrane-protein study, as it is a powerful yet gentle detergent

Fluorinated diglucose detergents for membrane-protein extraction.

International audienceFluorinated surfactants have scarcely been explored for the direct extraction of proteins from membranes because fluorination is believed to abrogate detergency. However, we have recently shown that a commercially available fluorinated surfactant readily solubilizes lipid membranes, thereby suggesting that fluorination per se does not interfere with detergent activity. In this work, we developed new fluorinated surfactants that exhibit detergency in terms of both lipid-vesicle solubilization and membrane-protein extraction. The compounds made and tested contain two glucose moieties as polar headgroup, a hydrogenated thioether linker, and a perfluorinated alkyl tail with either 4, 6, or 8 carbon atoms. The physicochemical properties of the micelles formed by the three fluorinated surfactants were evaluated by NMR spectroscopy, surface tensiometry, isothermal titration calorimetry, dynamic light scattering, small-angle X-ray scattering, and analytical ultracentrifugation. At 25 °C, micellization was mainly entropy-driven, and the CMC values were found to decrease with chain length of the fluorinated tail, whereas the aggregation number increased with chain length. Remarkably, all three surfactants were found to solubilize lipid vesicles and extract a broad range of proteins from Escherichia coli membranes. These findings demonstrate, for the first time, that nonionic fluorinated surfactants could be further exploited for the direct extraction and solubilization of membrane proteins

Faire science

L’histoire des disciplines académiques est loin d’être un fleuve tranquille. Dans leur recherche de reconnaissance et de financements, ou leur volonté de refondation, leurs praticiens sont amenés à redéfinir fréquemment ce qui légitime leur geste et la (re)production du corps. Un incessant travail de redéfinition en découle, toujours situé en un lieu et un temps donnés, qui consolide ou déplace les enjeux manifestes de la scientificité – cette justification névralgique. Pour interpréter de telles opérations, les propriétés des agents, la morphologie institutionnelle et la matérialité des pratiques sont des clés de lecture essentielles. Les enquêtes réunies dans ce dossier embrassent différents champs des sciences humaines et sociales (économie, sociologie, préhistoire, critique littéraire) sur une période allant des années 1920 aux années 1970, principalement en France et aux États-Unis. Elles soulignent le poids des enjeux politiques et stratégiques et l’importance des relations avec les autres sciences dès lors que l’on veut comprendre comment les sciences humaines et sociales affirment leur scientificité. Historians of academic disciplines do not have an easy time of it: in their quest for recognition and for funding, or their desire for refoundation, they often have to redefine what legitimates their activities and the (re)production of their research body. This constant work of redefinition, in a specific place and time, consolidates or displaces the manifest stakes of scientificity – the latter remaining capital. In order to interpret such operations, the properties of the agents, the institutional morphology of the practices, and their materiality, are essential keys to understanding. The contributions to this dossier embrace different fields of the humanities and social sciences (economics, sociology, prehistory, literary criticism) over a period ranging from the 1920s to the 1970s, mainly in France and the United States. The articles underline the significance of political and strategic issues, and the importance of relations with other sciences, for an undertanding of how the humanities and social sciences assert their scientificity

Assessment of the Minimal Targeted Biopsy Core Number per MRI Lesion for Improving Prostate Cancer Grading Prediction

Background: To study the impact of MRI characteristics and of targeted biopsy (TB) core number on the final grade group (GG) prediction. Materials and Methods: The cohort was 478 consecutive patients who underwent radical prostatectomy (RP) after positive mpMRI (multiparametric magnetic resonance imaging) followed by fusion TB. Endpoints were the upgrading and concordance rates between TB and RP specimens. Results: Upgrading rate after TB was 40.6%. Patients with upgrading had lower PIRADS (Prostate Imaging-Reporting and Data System) scores (p < 0.001), smaller lesion size (p = 0.017), fewer TB cores (p < 0.001), and lower TB density (p = 0.015) compared with cases with grade concordance. There was a significant continuous improvement in upgrading rate when TB core number per lesion increased from 56.3% to 25.6% when <2 or ≥5 TB cores were taken, respectively (p = 0.002). The minimal TB number per lesion to reduce upgrading risk to approximately 30%was 4 in PIRADS 3, and 3 in PIRADS 4–5 cases. Conclusions: Grade group prediction by TB is significantly improved by higher PIRADS score, larger lesion size, and increased TB per lesion. At least four TB cores should be taken in PIRADS 3 score lesions, whereas three cores seem enough in PIRADS 4–5 cases to improve GG prediction and limit upgrading risk

Epidemiology of metastatic castration-resistant prostate cancer: A first estimate of incidence and prevalence using the French nationwide healthcare database

International audienceBackground: There is a lack of information about the burden of metastatic castration-resistant prostate cancer (mCRPC). The present work aims to estimate the incidence and prevalence of mCRPC in 2014 using the French nationwide healthcare database (SNDS).Methods: Prevalence and incidence were estimated based on an SNDS extraction of men covered by the general healthcare insurance (86 % of the French population), and aged ≥40. Patients with mCRPC were identified amongst prostate cancer cases using an algorithm estimating a date of first metastasis management and a date of castration resistance. This algorithm was validated by clinical experts through a blind review of 200 anonymized medical charts from SNDS data. Prevalence and incidence were standardized on the European Standard Population (2013 edition).Results: Prevalence and incidence of mCRPC were estimated as, respectively, 62 and 21 cases per 100 000 men in 2014. Less than one mCRPC case per 100 000 was observed in men aged 40-49. Maximum mCRPC incidence was in men aged 80-89 (175 per 100 000). The algorithm used for mCRPC identification had 97 % positive and 99 % negative predictive values.Conclusion: The good performances of the algorithm for mCRPC identification and the consistency of the generated results with the existing data highlight the robustness of these first estimates of mCRPC prevalence and incidence. Future updates will call for algorithm adjustment as practices evolve over time. These first real-life data will serve for future follow-up of the impact of changes in the management of prostate cancer