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In this work, we revisited the disassembly approach (also known as the Zelder's approach) recently proposed for sensing pyrophosphate (PPi) in water and based on the decomposition of metal-salen complexes. A systematic study devoted to the structural optimization of this novel class of PPi-responsive fluorogenic probes was conducted. Screening of eight different vicinal diamines (i.e., bridge of the salen ligand) combined with the use of 8-formyl-7-hydroxycoumarin (i.e., salicylaldehyde derivative) as the fluorescent reporter, has led to a set of novel and fully characterized coumarin-salen Fe(III) complexes. A series of analytical validations helped us to identify that coumarin-salen Fe(III) complexes derived from ethylenediamine and racemic 1,2-propylenediamine backbones exhibit the best and selective PPi-sensing performances (the limits of detection were estimated as 3.15 × 10-6 M and 2.81 × 10-6 M respectively). The implementation of both fluorescence time-course measurements and RP-HPLC-fluorescence analyses has enabled us to gain further insights into the disassembly-based probes' activation mechanism. This study therefore contributes to demonstrate that the disassembly approach is a valuable strategy to achieve fluorogenic activity-based sensing of anions.

Over the past 35 years, geothermal projects have been developed in the Upper Rhine Graben (URG) to exploit deep geothermal energy. Underneath approximately 2 km of sedimentary deposits, the deep target consists of a granitic basement, which is highly fractured and hydrothermally altered. Therefore, it has high potential as a geothermal reservoir. Despite dense 2D seismic data coverage originally acquired for oil exploration (for a target two-way traveltime between 300 and 700 ms), the faults at the top of the granitic basement (between 1400 and 4000 ms) are poorly imaged, and their locations remain uncertain. To gain a better understanding of this large-scale faulting and to ensure the viability of future geothermal projects, a 3D seismic survey was acquired in the French part of the URG during the summer of 2018. This paper describes how an integrated project, combining seismic data processing, high-end imaging, and enhanced interpretation, was conducted to improve the understanding of this complex basin for geothermal purposes. By revealing the deep granite layer and its complex associated fault network, the insight from this project can help accurately locate future production wells.

International audience; Limnothrissa miodon is a small pelagic clupeid that was introduced into Lake Kivu in the late 1950s to fill an empty niche. Since then, it has become the main fishery in the lake. The fish stocks were estimated by hydroacoustics between 2012 and 2018 to provide information on the fishery in the current context of changing environmental factors. The main objectives were to determine the most appropriate season for assessing stock dynamics, to characterize temporal and spatial distribution in L. miodon populations and to compare with previous surveys to help predict status of its stocks. The fish size distribution showed that the long dry season was the most appropriate season for assessing the stocks, as it provides information of recruitment for the year. The south and west basins always had higher densities (1.23 m(2)/ha) and biomass (21-22.7 kg/ha) than the north basins (0.62-0.77 m(2)/ha; 15.3-16.5 kg/ha). The stock showed declining trend from 7,000 t in 1985 to 1,000 t in 2012 and thereafter consistently increased to 4,000 t in 2018. This last value is similar to previous estimates of 1990s and 2008, showing that the stocks of L. miodon are stable. The low 2012 values could be due to particular environmental conditions in 2012-2014, when there was a shift from diatoms and cyanobacteria to green algae. There is therefore a need to combine high-quality environmental data with fishery surveys to better understand the dynamic of fish and fishery especially under the increasing influence of climate change on lake productivity processes. (C) 2020 International Association for Great Lakes Research.

We describe the synthesis of a range of 6’-triazolyl-dihydroxanthene-hemicyanine (DHX-hemicyanine) fused dyes through an effective copper-catalyzed azide-alkyne cycloaddition (CuAAC) "click" reaction, with the dual aim of providing molecular diversity and fine tuning spectral properties of these near-infrared (NIR)-active materials. This was implemented by reacting 16 different aliphatic and aromatic azides with a terminal alkynyl-based-DHX-hemicyanine hybrid scaffold prepared in four steps and 35% overall yield from 4-bromosalicylaldehyde. The resulting triazole derivatives have been fully characterized and their optical properties determined both in organic solvents and simulated physiological conditions (phosphate buffered saline containing 5% of bovine serum albumin protein). This systematic study is a first important step towards the development of NIR-I fluorogenic "click-on" dyes or related photoactive agents for light-based diagnostic and/or therapeutic applications.

International audience; We study discrete-time simulation schemes for stochastic Volterra equations, namely the Euler and Milstein schemes, and the corresponding Multi-Level Monte-Carlo method. By using and adapting some results from Zhang [22], together with the Garsia-Rodemich-Rumsey lemma, we obtain the convergence rates of the Euler scheme and Milstein scheme under the supremum norm. We then apply these schemes to approximate the expectation of functionals of such Volterra equations by the (Multi-Level) Monte-Carlo method, and compute their complexity. We finally provide some numerical simulation results.

Le developpement et la banalisation de la nasse au sein des manifestations invitent a analyser cette pratique au prisme du droit europeen des droits de l'Homme, plus particulierement du droit de circuler librement, du droit de ne pas etre arbitrairement prive de sa liberte, du droit de manifester et de celui de ne pas subir de traitement inhumain ou degradant. Si le nouveau Schema national du maintien de l’ordre ne prevoit pas cette pratique, elle perdure comme technique policiere. La question prioritaire de constitutionnalite n’ayant pu aboutir, il revient a la Cour de cassation, saisie du dossier sur la nasse de place Bellecour a Lyon en 2010 d’appliquer la Convention, telle qu’interpretee par la Cour europeenne des droits de l’Homme : un retour sur ce dispositif s’impose.

Les observateurs indépendants sont des défenseurs des droits de l’Homme qui ont notamment pour mission de surveiller et de rendre compte du respect des libertés publiques dans les pratiques policières. Leur protection est consacrée par le droit international et européen depuis plusieurs années. En France, en revanche, ils ne sont ni reconnus, ni protégés par le droit interne, et sont régulièrement victimes d’atteintes concrètes dans l’exercice de leurs missions. The protection of independent observers is enshrined in international et European law for a couple of years now. As human rights defenders, their mission is namely to monitor and report respect for public freedoms in law enforcement practices. In France, legal observers are neither recognized nor protected by domestic law and are often victims of concrete abuses in the exercise of their missions.

International audience; We describe an expedient access to a 5', 6', 7'-trifluoro dihydroxanthene-hemicyanine fused scaffold in 2 steps and 54% overall yield from the corresponding salicylic aldehyde. A 6'-regioselective nucleophilic aromatic substitution (SNAr) reaction with a wide range of nitrogen, sulfur or selenium nucleophiles then gives access to 16 near-infrared (NIR) fluorophores emitting in the 710-750 nm range. We also report the experimental and theoretical photophysical investigations of these unique optical agents that include the first series of 6'-heavy atom substituted dihydroxanthenes, extending the pool of polyfluorinated markers for biomedical and material applications.

International audience; A novel class of rosamine dyes bearing a 7-substituted 4-hydroxycoumarin unit as meso-heteroaryl ring is presented. The latent C-nucleophilic character of 4-hydroxycoumarin derivatives (i.e., their C-3 position as nucleophilic center) has been drawn on in the designing of two unprecedented synthetic routes towards these atypical xanthene dyes. They are based on an effective formal Knoevenagel condensation with either pyronin derivatives or a mixed bis-aryl ether bearing both an aldehyde and a masked phenylogous amine, possibly applicable to a wide range of latent cyclic C-nucleophiles. We also report experimental and theoretical photophysical investigations of these unique coumarin-pyronin hybrid structures and particularly their form low-lying quenching states, some of dark twisted intramolecular charge transfer (TICT) nature, depending on the medium (CHCl3 and water). Furthermore, two fluorophore compounds 9 and 11 have been applied for imaging in paraformaldehyde-fixed A549 cells to gain insights into their permeation and localization.

A novel class of rosamine dyes bearing a 7-substituted 4-hydroxycoumarin unit as meso-heteroaryl ring is presented. The latent C-nucleophilic character of 4-hydroxycoumarin derivatives (i.e., their C-3 position as nucleophilic center) has been drawn on in the designing of two unprecedented synthetic routes towards these atypical xanthene dyes. They are based on an effective formal Knoevenagel condensation with either pyronin derivatives or a mixed bis-aryl ether bearing both an aldehyde and a masked phenylogous amine, possibly applicable to a wide range of latent cyclic C-nucleophiles. We also report experimental and theoretical photophysical investigations of these unique coumarin-pyronin hybrid structures and particularly their form low-lying quenching states, some of dark twisted intramolecular charge transfer (TICT) nature, depending on the medium (CHCl3 and water). Furthermore, two fluorophore compounds 9 and 11 have been applied for imaging in paraformaldehyde-fixed A549 cells to gain insights into their permeation and localization.

International audience; This paper describes the study of an original ("power electronic-less") AC electrical architecture for propulsive purposes in aeronautics. This architecture is composed of two or more Permanent Magnets Synchronous Machines (PMSM) directly linked to each other by an AC bus, one in generator mode driven by a gas turbine and all the other PMSM in motor mode, each one driving a propeller. The simple architecture with only two PMSM-one generator and one motor-will be mainly developed here. Although this architecture may seem too rigid to be implemented, the absence of power electronic offers potential savings in mass and costs, which justifies its study to determine whether this architecture could be implemented and used for propelling systems or not. This paper focuses on the development of an analytical model enabling to fully describe the dynamic and permanent behaviour of such an architecture. Once this model is set, the stability of the architecture is analysed: a classical approach, with the linearization of the analytical model and the use of root locus analysis, is considered.

Volume 11, no. 5, e01774-20, 2020, [https://doi.org/10.1128/mBio.01774-20][1]. Professor Birgitta Henriques-Normark’s last name was missing a hyphen between Henriques and Normark in the original article. The byline should appear as shown above. Also, the affiliations and affiliation letters are

Molecular mechanisms by which sex steroids interact with P. aeruginosa to modulate its virulence have yet to be reported. Our work provides the first characterization of a steroid-induced membrane stress mechanism promoting P. aeruginosa virulence, which includes the release of proinflammatory outer membrane vesicles, resulting in inflammation, host tissue damage, and reduced bacterial clearance. We further demonstrate that at nanomolar (physiological) concentrations, male and female sex steroids promote virulence in clinical strains of P. aeruginosa based on their dynamic membrane fluidic properties. This work provides, for the first-time, mechanistic insight to better understand and predict the P. aeruginosa related response to sex steroids and explain the interindividual patient variability observed in respiratory diseases such as cystic fibrosis that are complicated by gender differences and chronic P. aeruginosa infection., Estrogen, a major female sex steroid hormone, has been shown to promote the selection of mucoid Pseudomonas aeruginosa in the airways of patients with chronic respiratory diseases, including cystic fibrosis. This results in long-term persistence, poorer clinical outcomes, and limited therapeutic options. In this study, we demonstrate that at physiological concentrations, sex steroids, including testosterone and estriol, induce membrane stress responses in P. aeruginosa. This is characterized by increased virulence and consequent inflammation and release of proinflammatory outer membrane vesicles promoting in vivo persistence of the bacteria. The steroid-induced P. aeruginosa response correlates with the molecular polarity of the hormones and membrane fluidic properties of the bacteria. This novel mechanism of interaction between sex steroids and P. aeruginosa explicates the reported increased disease severity observed in females with cystic fibrosis and provides evidence for the therapeutic potential of the modulation of sex steroids to achieve better clinical outcomes in patients with hormone-responsive strains.

International audience; This paper examines the Root solution of the Skorohod embedding problem given full marginals on some compact time interval. Our results are obtained by limiting arguments based on finitely-many marginals Root solution of Cox, Oblój, and Touzi. Our main result provides a characterization of the corresponding potential function by means of a convenient parabolic PDE.

We report a rational and systematic study devoted to the structural optimisation of a novel class of protease-sensitive fluorescent probes that we recently reported (S. Debieu and A. Romieu, Org. Biomol. Chem., 2017, 15, 2575-2584), based on the "covalent-assembly" strategy and using the targeted enzyme penicillin G acylase as a model protease to build a fluorescent pyronin dye by triggering a biocompatible domino cyclisation-aromatisation reaction. The aim is to identify ad hoc probe candidate(s) that might combine fast/reliable fluorogenic "turn-on" response, full stability in complex biological media and ability to release a second molecule of interest (drug or second fluorescent reporter), for applications in disease diagnosis and therapy. We base our strategy on screening a set of active methylene compounds (C-nucleophiles) to convert the parent probe to various pyronin caged precursors bearing Michael acceptor moieties of differing reactivities. In vitro stability and fluorescent enzymatic assays combined with HPLC-fluorescence analyses provide data useful for defining the most appropriate structural features for these fluorogenic scaffolds depending on the specifications inherent to biological application (from biosensing to theranostics) for which they will be used.

International audience; Mobile acoustic techniques (echo-sounding and echo-integration) for fish surveys were used in shallow waters of depths less than 5 m. These techniques show the importance of fish biomass in the side-channels and the detection of echoes in the main channel. Diurnal spatial migrations are seen. The advantages and limitations of the method as a complement to traditional sampling methods in the river are examined.

We report a rational and systematic study devoted to structural optimisation of a novel class of protease-sensitive fluorescent probes recently reported by us (Org. Biomol. Chem., 2017, 15, 2575-2584), based on the "covalent-assembly" strategy and using the targeted enzyme (penicilin G acylase as model protease) to build a fluorescent pyronin dye by triggering a biocompatible domino cyclisation-aromatisation reaction. The aim is to identify ad hoc probe candidate(s) that might combine fast/reliable fluorogenic "turn-on" response, full stability in complex biological media and ability to release a second molecule of interest (drug or second fluorescent reporter), for applications in disease diagnosis and therapy. We base our strategy on screening a set of active methylene compounds (C-nucleophiles) to convert the parent probe to various pyronin caged precursors bearing Michael acceptor moieties of differing reactivity. In vitro stability and fluorescent enzymatic assays combined to HPLC-fluorescence analyses provide data useful to define the most appropriate structural features for these fluorogenic scaffolds depending on the specifications required by the biomedical application (e.g., in vivo molecular imaging, image-guided drug delivery and theranostics) for which they will be used.

International audience; In this paper we solve real-valued rough differential equations (RDEs) reflected on an irregular boundary. The solution $Y$ is constructed as the limit of a sequence $(Y^n)_{n\in\mathbb{N}}$ of solutions to RDEs with unbounded drifts $(\psi_n)_{n\in\mathbb{N}}$. The penalisation $\psi_n$ increases with $n$. Along the way, we thus also provide an existence theorem and a Doss-Sussmann representation for RDEs with a drift growing at most linearly. In addition, a speed of convergence of the sequence of penalised paths to the reflected solution is obtained. We finally use the penalisation method to prove that the law at time $t>0$ of some reflected Gaussian RDE is absolutely contiuous with respect to the Lebesgue measure.

Domino Michael-aldol annulation of cycloalkane-1,3-diones with enals affords a general route to 6-hydroxybicyclo[3.3.1]nonane-2,9-diones and 2-hydroxybicyclo[3.2.1]octane-6,8-diones, notably in one-pot procedures under convenient conditions. The annulation is shown to be compatible with one or more substituents at six positions of the bicyclo[3.3.1]nonane-2,9-dione scaffold. In some cases, the relative configuration of the product can be controlled by the appropriate choice of solvent, base and temperature for the annulation. In contrast to the chair–chair conformations usually adopted, the bicyclo compounds derived from 2,4,4-trimethylcyclohexane-1,3-dione possessed boat-chair conformations. Oxidation of the annulation products gave the corresponding bicyclo triketones.

International audience; Long-range dependence (LRD) has been observed in a variety of phenomena in nature, and for several years also in the spiking activity of neurons. Often, this is interpreted as originating from a non-Markovian system. Here we show that a purely Markovian integrate-and-fire (IF) model, with a noisy slow adaptation term, can generate interspike intervals (ISIs) that appear as having LRD. However a proper analysis shows that this is not the case asymptotically. For comparison, we also consider a new model of individual IF neuron with fractional (non-Markovian) noise. The correlations of its spike trains are studied and proven to have LRD, unlike classical IF models. On the other hand, to correctly measure long-range dependence, it is usually necessary to know if the data are stationary. Thus, a methodology to evaluate stationarity of the ISIs is presented and applied to the various IF models. We explain that Markovian IF models may seem to have LRD because of non-stationarities.

Using a computational approach combining the Time-Dependent Density Functional Theory (TD-DFT) and the second-order Coupled Cluster (CC2) approaches, we investigate the spectral properties of a large panel of nor-dihydroxanthene (DHX)-hemicyanine fused dyes. First we compare the theoretical and experimental 0-0 energies for a set of 14 known synthetic compounds and show that a remarkable agreement between theory and experiment is obtained when a suitable environmental model is selected. In addition, we obtain vibrationally-resolved spectra for several compounds and theory also accurately reproduces the experimental band shapes. We show that the electronic transitions in nor-DHX-based fluorophores are associated with small variations of the dipole moments but large oscillator strengths. Using various chemical strategies, we design a series of compounds with red-shifted 0-0 energies.

Using structures of Abstract Wiener Spaces, we define a fractional Brownian field indexed by a product space ( 0 , 1 / 2 ] × L 2 ( T , m ) , ( T , m ) a separable measure space, where the first coordinate corresponds to the Hurst parameter of fractional Brownian motion. This field encompasses a large class of existing fractional Brownian processes, such as Levy fractional Brownian motions and multiparameter fractional Brownian motions, and provides a setup for new ones. We prove that it has satisfactory incremental variance in both coordinates and derive certain continuity and Holder regularity properties in relation with metric entropy. Also, a sharp estimate of the small ball probabilities is provided, generalizing a result on Levy fractional Brownian motion. Then, we apply these general results to multiparameter and set-indexed processes, proving the existence of processes with prescribed local Holder regularity on general indexing collections.

Synthesis of 3-fluoro-2-hetarylindoles through addition of hetarenes to 3,3-difluoroindolium ions generated in situ by Zn(OTf)2-catalyzed oxazolidine ring opening is described. Indoles, pyrroles and alkyl-substituted furans can be used as hetaryl nucleophiles to afford a range of 3-fluoro-2-hetarylindole products 6 in 56–95 % yields. A diverse array of 3,3-difluorinated 2-hetarylindolines 7 can also be synthesized in 43–84 % yields by a tandem sequential process that involves hetarene nucleophilic addition, HF elimination and fluorocyclization reactions. Our study by 1H NMR and UV/Vis spectroscopy reveals that 3,3-difluorinated 2-hetarylindolines possess interesting substituent-dependent acidochromic properties. UV absorption and fluorescence spectra of selected compounds 6 and 7 are also studied.

International audience; The effective synthesis of extended conjugated N, N-dialkylamino-nor-dihydroxanthene-based fluorophores is described from diversely functionalized salicylic aldehydes. The access to these original fluorescent derivatives proceeded in two steps through a one-pot construction of the unusual nor-dihydroxanthene (nor-DHX) scaffold followed by a diversification step providing a wide variety of nor-DHXhemicyanine fused dyes emitting in the range of 730790 nm. The versatility of our approach has enabled a further extension to the late-stage introduction of negatively/posi-tively charged polar groups onto their terminal nitrogen heterocyclic subunit, thereby giving access to the first watersoluble and/or bioconjugatable members of this emerging class of NIR fluorophores. Our water-solubilizing method is easily implementable, and the nor-DHX-hemicyanine skeleton maintains satisfying fluorescence quantum yields (520%) under physiological conditions. Finally, the bioconjugation ability of fluorescent derivatives bearing a free carboxylic acid was demonstrated through the covalent labeling of a model protein, namely, bovine serum albumin.

A five-step synthesis of the 6-6-6 tricyclic skeleton of the diterpene wickerol A is described. The synthesis features a diastereoselective d-proline-mediated Robinson annulation and N-heterocyclic carbene-catalyzed Stetter reaction as key transformations to give the tricyclic carbon skeleton of this promising anti-influenza A natural product.

International audience; The effects of biotic (density-dependent) and environmental (flow and temperature) factors on the apparent survival, mean length and size variation of a low-density brown trout population in the juvenile stage, that is, from their first summer (0+) to the end of the second year (1+), were determined. Apparent survival was negatively related to the age class density during the three periods (first summer, first winter and second summer). A significant interaction between the mean flow and 0+ density highlighted a gradient towards strong density dependence acting on fish loss (i.e., mortality or migration) with decreasing summer flow. Conversely, no density dependence was reported at higher mean flows. The mean length was determined by density-dependent and density-independent (temperature and flow) factors throughout the study period. The negative relationship between fish length and intracohort density was highly significant during the three periods. The yearling (1+) density was negatively related to 0+ fish length measured after the first summer, suggesting intercohort effects. A positive effect of temperature on fish length was observed. Mean length after the summer seasons (0+ and 1+ fish) was also positively related to mean flow. Fish size variation around the mean measured with the coefficient of variation (CV) increased with increasing 0+ densities, both at the end of the first summer and the first winter. Results suggested that density-dependent and density-independent factors acted jointly on apparent survival and growth with a predominance of biotic processes. We discussed the potential implications of density-dependent regulations on growth and survival for population resilience after catastrophic events.

The fluorescence retention and intensity of juvenile brown trout Salmo trutta marked during their first summer were monitored in a hatchery and in four natural streams. A handheld detector was used for direct examination. In the hatchery, three marking treatments (T) were compared: 3· 5m in in a 0·5% calcein solution (T0·5-3·5), 7 min in a 0·5% calcein solution (T0·5-7) and 3·5 min in a 1% calcein solution (T1-3·5). The fish were raised indoors for 11 months and then outdoors until 18 months. The fluorescence retention rate was 100% in all treatments at 11 months, although T1-3·5 showed the highest mean fluorescence intensity, followed by T0·5-7 and T0·5-3·5. The fluorescence intensity was not correlated with the final total length (LT) of the fish in two treatments, although it significantly decreased with increasing LT in T1-3·5. At 18 months

(+)-Hyperforin (1) is a polyprenylated acylphloroglucinol (PPAP) natural product isolated in 1971 from Hypericum perforatum. Also known as St. John's wort, Hypericum perforatum is a popular medicinal plant because of its antidepressant properties. (+)-Hyperforin (1) is the main component of the plant and has attracted the interest of the scientific community since it was identified as the agent responsible for the antidepressant activity. The subsequent discovery that it also displayed a wide range of biological activities triggered the interest of synthetic chemists because of its appealing, compact molecular structure. This microreview presents an overview of the synthetic studies reported so far for the racemic and enantioselective syntheses of (+)-hyperforin (1) and analogues, and attempts to shed light on the intriguing structure–activity relationships (SARs) of the natural product.

Les plages constituent un enjeu stratégique tant du point de vue de l’environnement que de l’économie touristique des régions littorales. Or celles-ci sont soumises à des processus d’érosion de plus en plus importants. Les réponses des politiques publiques, d’abord centrées sur la construction d’ouvrages de défense, s’orientent de plus en plus vers des mesures dites douces, notamment de rechargement des plages en sable. Une opération de grande ampleur a ainsi eu lieu en 2008 dans le Golfe d’Aigues Mortes, dont il s’agit de tirer des enseignements, en étudiant les perceptions des usagers. Après avoir rappelé les intérêts et les effets négatifs de ces mesures, cet article présente la perception que les usagers ont des plages, notamment l’importance qu’ils accordent à leur taille et leurs points de vue sur les pratiques de rechargement. L’ensemble de ces résultats permet d’éclairer les besoins de communication et de sensibilisation qui doivent être mis en place pour accompagner ces actions. Beaches, which are of strategic importance for both the environment and the tourism industry in coastal zones, are subject to worsening erosion. Public policies first addressed the erosion issue through the construction of sea defenses but are now moving towards soft measures, in particular beach sand nourishment. A large-scale nourishment operation was carried out in 2008 in the Gulf of Aigues Mortes and lessons can be learned from the study of user perceptions. This article begins by addressing both the positive and negative impacts of such measures. It then discusses users’ perceptions of beaches, in particular the significance that they attach to their size, and their viewpoints on beach nourishment practices. The results clarify the communication and awareness-raising efforts needed to promote such actions.

International audience; We evaluated the effect of 12-mm passive integrated transponder (PIT) tag implantation on age-0 brown trout Salmo trutta. The effects of implantation method (i.e. surgical incision or injection) and individual tagger on survival, tag retention and growth were assessed during a 60-day hatchery experiment. Two size classes of fish (total length) were considered: small (50-55 mm) and large (56-63 mm). For fish 55 mm), neither implantation method nor tagger affected survival (mean = 93.2%), tag retention (mean = 86.6%), and growth rate (mean SD specific growth rate = 1.07 0.48% during the first 30 days). A slight slowdown in growth (length) appeared within 30 days post-tagging but was compensated at 60 days. Results suggest that implanting 12-mm PIT tags in salmonids smaller than 55 mm (TL), by different taggers and using either surgery or injection, may have significant effects on survival, tag retention, and growth. (C) 2013 Elsevier B.V. All rights reserved.

International audience; A late-stage amination of a bifunctional dihydroxanthene (DHX) scaffold is reported to access a wide variety of new near-infrared (NIR) chromophores/fluorophores. The divergent approach allows the coupling of aliphatic and aromatic amines and readily provides molecular diversity shedding light on the structure fluorescence relationship of this emerging class of NIR fluorophores.

International audience; An expedient synthesis of amino-(nor)dihydroxanthene-based fluorophores is reported, proceeding in two steps from commercially available salicylic aldehydes. The synthesis relies on the one-pot construction of the (nor)dihydroxanthene scaffolds through an oxa-Michael/retro-Michael/vinylogous aldol/dehydration cascade sequence. Further extension of the π-conjugated systems through a condensation reaction with a 2,4,6-trisubstituted pyrylium salt led to a novel class of near-infrared (NIR) fluorescent dyes with absorption/emission maxima in polar media in the ranges of 705–778 and 785–828 nm, respectively.