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International audience; The activation of carbon dioxide by three different Mo‐diimine complexes [Mo(CO) 4 (L)] (L = bipyridine (bpy), 1,10‐phenantroline (phen) or pyridylindoziline (py‐indz)) has been investigated by electrochemistry and spectroelectrochemistry. Under inert atmosphere, monoreduction of the complexes is ligand‐centred and leads to tetracarbonyl [Mo(CO) 4 (L)] •− species, whereas double reduction induces CO release. Under CO 2 , [Mo(CO) 4 (L)] complexes undergo unexpected coupled chemical‐electrochemical reactions at the first reduction step, leading to the formation of reduced CO 2 derivatives. The experimental results obtained from IR, NIR and UV‐Vis spectroelectrochemistry, as well as DFT calculations, demonstrate an electron‐transfer reaction whose rate is ligand‐dependent.

Therapy resistance represents a major clinical challenge in acute myeloid leukemia (AML). Here we define a ‘MitoScore’ signature, which identifies high mitochondrial oxidative phosphorylation in vivo and in patients with AML. Primary AML cells with cytarabine (AraC) resistance and a high MitoScore relied on mitochondrial Bcl2 and were highly sensitive to venetoclax (VEN) + AraC (but not to VEN + azacytidine). Single-cell transcriptomics of VEN + AraC-residual cell populations revealed adaptive resistance associated with changes in oxidative phosphorylation, electron transport chain complex and the TP53 pathway. Accordingly, treatment of VEN + AraC-resistant AML cells with electron transport chain complex inhibitors, pyruvate dehydrogenase inhibitors or mitochondrial ClpP protease agonists substantially delayed relapse following VEN + AraC. These findings highlight the central role of mitochondrial adaptation during AML therapy and provide a scientific rationale for alternating VEN + azacytidine with VEN + AraC in patients with a high MitoScore and to target mitochondrial metabolism to enhance the sensitivity of AML cells to currently approved therapies. Sarry and colleagues demonstrate that adaptive resistance to venetoclax + cytarabine therapy in acute myeloid leukemia relies on mitochondrial respiration and show that combination with electron transport chain complex inhibitors delays relapse in patient-derived xenograft models in vivo.

In the past few decades, glyphosate became the most used herbicide substance worldwide. As a result, the substance is ubiquitous in surface waters. Concerns have been raised about its ecotoxicological impact, but little is known about its generational toxicity. In this study, we investigate the impact of an environmentally relevant concentration of glyphosate and its co-formulants on an F2 generation issued from exposed generations F0 and F1. Trans, inter and multigenerational toxicity of 1 μgL-1 of the active substance was evaluated on early stages of development and juvenile rainbow trout (Oncorhynchus mykiss) using different molecular, biochemical, immuno-hematologic, and biometric parameters, behavior analysis, and a viral challenge. Reproductive parameters of generation F1 were not affected. However, developmental toxicity in generation F2 due to glyphosate alone or co-formulated was observed with head size changes (e.g. head surface up to +10%), and metabolic disruptions (e.g. 35% reduction in cytochrome-c-oxidase). Moreover, larvae exposed transgenerationally to Viaglif and intergenerationally to glyphosate and Roundup presented a reduced response to light, potentially indicating altered escape behavior. Overall methylation was, however, not altered and further experiments using gene-specific DNA metylation analyses are required. After several months, biochemical parameters measured in juvenile fish were no longer impacted, only intergenerational exposure to glyphosate drastically increased the susceptibility of rainbow trout to hematopoietic necrosis virus. This result might be due to a lower antibody response in exposed fish. In conclusion, our results show that generational exposure to glyphosate induces developmental toxicity and increases viral susceptibility. Co-formulants present in glyphosate-based herbicides can modulate the toxicity of the active substance. Further investigations are required to study the specific mechanisms of transmission but our results suggest that both non-genetic mechanisms and exposure during germinal stage could be involved.

International audience; The electrochemically-induced CC bond making/breaking for six differently R-substituted phenylmethylenepyrans has been investigated by voltammetry in organic media. All compounds display an irreversible oxidation peak whose potential is fully dependent on the electrophilic property of the substituent R. The electrochemical oxidation yields bis-pyrylium compounds by σ-σ CC bond formation. The initial methylenepyrans are recovered by cleavage of the CC bond through electrochemical reduction of the bis-pyrylium species. According to the voltammetric analysis, the mechanistic pathway, radical-radical or radical-substrate, for the intermolecular dimerization is fully R-dependent. Electronic structure calculations show that the spin population in the radical cation and the strength of the σ-σ CC bond in the dimer strongly depend on the nature of R. In addition, low-temperature electrochemical voltammetry (175 K), and room-temperature high scan rate cyclic voltammetry have been used to unravel the kinetics of the CC bond formation.

BACKGROUND Whereas platelet transfusion is a common medical procedure, inflammation still occurs in a fraction of transfused individuals despite the absence of any apparent infectious agents. Platelets can shed membrane vesicles, called extracellular vesicles (EVs), some of which contain mitochondria (mito+EV). With its content of damage-associated molecular pattern (DAMP), the mitochondrion can stimulate the innate immune system. Mitochondrial DNA (mtDNA) is a recognized DAMP detected in the extracellular milieu in numerous inflammatory conditions and in platelet concentrates. We hypothesized that platelet-derived mitochondria encapsulated in EVs may represent a reservoir of mtDNA. STUDY DESIGN AND METHODS Herein, we explored the implication of mito+EVs in the occurrence of mtDNA quantified in platelet concentrate supernatants that induced or did not induce transfusion adverse reactions. RESULTS We observed that EVs were abundant in platelet concentrates, and platelet-derived mito+EVs were more abundant in platelet concentrates that induced adverse reactions. A significant correlation (rs = 0.73; p

International audience; Four new ternary Ni(ii) and Cu(ii) complexes of ONO tridentate Schiff base and pyridylmethylenepyran (PyMP) ligands [(R-ONO)M(PyMP)] (R = anisyl = An M = Ni 1, Cu 2; R = ferrocenyl = Fc M = Ni 3, Cu 4) have been synthesized under facile reaction conditions starting from R-ONOH2, metal(ii) nitrate salts, and PyMP; R-ONOH2 stands for the Schiff base ligand precursors obtained by condensation of either 1-anisyl- or 1-ferrocenyl-butan-1,3-dione and 2-aminophenol. They have been thoroughly characterized with the help of various physicochemical tools, such as CHN analyses, IR and UV-vis spectra, H-1 NMR for diamagnetic Ni(ii) derivatives 1 and 3, and HRMS for paramagnetic Cu(ii) species 2 and 4. The molecular structures of 1-3 were authenticated by single-crystal X-ray diffraction methods, along with that of the doubly phenoxide-bridged dimer [Cu-2(mu-ONO-Fc)(2)(PyMp)(2)] (4 '), resulting from the recrystallization of 4. In 1-3, the four-coordinate nickel and copper atoms adopt a square planar geometry, whereas in 4 ' the Cu-II metal ion is five-coordinated in a square pyramidal environment with the pyridyl nitrogen occupying the apex. Electrochemical studies reveal two well-separated redox waves. The spin density distribution analyses reveal that the initial oxidation process is associated with a ligand-based level, with some ferrocenyl participation for the heterobimetallic compounds 3 and 4. Reversible redox switching can be established for 1 and 3 by time-resolved spectroelectrochemistry under thin-layer conditions where electrochemical cycling is associated with a significant modification of the UV-vis spectra of the chromophores. The second-order nonlinear optical responses of 1-4 along with those of assumed bispyrylium dimeric species 5 and 6, generated by chemical oxidation of 1 and 3, respectively, have been determined by harmonic light scattering measurements in dichloromethane solutions at 1.91 mu m incident wavelength. Rather high beta values ranging from 270-530 x 10(-30) esu were determined for 1-4. The beta value of 5 (800 x 10(-30) esu) was found to be almost twice that of its monomeric precursor 1, whereas the beta value of 6 (160 x 10(-30) esu) is reduced by half with respect to that of 3. In 5 the anisyl retains its donor ability whereas in 6 the electron-donating character of the oxidized ferrocenyl moiety is cancelled. Optimized geometries of the four compounds 1-4 as well as their electronic structures and that of their respective cations 1(+)-4(+) have been analyzed through DFT calculations, while TD-DFT computation has been used to interpret the major features of the UV-vis spectra.

In the Transchem project, rainbow trout genitors were exposed to environmental concentrations of pendimethalin over a period of 18 months and two new first generations of offspring, F1_2013 and F1_2014, were obtained. We investigated the impact of direct chemical exposure on juveniles as well as the potential cumulative transgenerational and direct effects on the larval development and on the pathogen susceptibility of offspring. Depending on the chemical treatment or not of the adults, their offspring were distributed in the tanks of our experimental system, in two batches i.e. juveniles from the control genitors (G-) and others from the contaminated ones (G+), and then, half of the tanks were exposed daily to pendimethalin (Off+) while the others were used as controls (Off-). Viral challenges were performed on the offspring, before and after three months of direct chemical exposure, with strains of infectious hematopoietic necrosis virus (IHNV), viral haemorrhagic septicemia virus (VHSV) and sleeping disease alphavirus (SDV). Direct and transgenerational macroscopic effects were observed on offspring, with a percentage of abnormalities in offspring derived from the genitors exposed to pendimethalin (G+) significantly higher compared to those from the genitors from non-exposed group (G-). Before the direct chemical exposure, similar kinetics of mortality was observed between the offspring from the contaminated or control genitors after VHSV infection. With IHNV, the G+ group died in a slightly larger proportion compared to the G- group and seroconversion was greater for the G- group. For the SDV challenge, the mortality was delayed for the G+ offspring compared to the G- and seroconversion reached 65% in the G+ group compared to 45% in the G-, with similar antibody titres. After three months of direct chemical exposure, kinetics of mortality induced by IHNV infection were similar for all groups studied. Infection with SDV resulted in a cumulative mortality of 40% for the G- groups (Off- and Off+), significantly higher than those observed from the contaminated genitors G+. Proportion of seropositivity for SDV varied from 24 to 47% depending on the group, with very low quantities of secreted antibodies. Lastly, the direct exposure of offspring could impact the capacity of fish to adapt their haematological parameters to environmental and physiological changes, and underlines the potential toxic effects on the next generations.

International audience; We report herein the structural properties and nitroaromatic sensing performances of fluorescent thin films formed by alternating donor-acceptor pi-conjugated chromophores. The incorporation of a flexible one-dimensional alkyl chain in the chromophore backbone drastically accelerates by more than one order of magnitude the sensing dynamics for the detection of 2,4-dinitrotoluene (DNT) vapors.

In the framework of the High-Luminosity Large Hadron Collider, the installation of a new generation of quadrupole magnets is foreseen on each side of ATLAS and CMS experiments. The new magnets are based on Nb3Sn technology and shall be able to reach an ultimate current of 17.9 kA with a peak field of 12.3 T in the coil. In 2016 and 2017, the first two short models, called MQXFS3 and MQXFS5, have been tested at 4.2 and 1.9 K in the two new test benches at the European Organization for Nuclear Research. This paper presents the result of the quench performance of the two models; the first magnet reached nominal but failed to reach ultimate, showing detraining in one coil. MQXFS5 reached ultimate performance without any detraining phenomena, validating the PIT conductor used for the first time in this magnet program.

Glyphosate is a commonly used agrochemical active substance co-formulated in glyphosate-based herbicides (GBHs) whose environmental safety is still a subject of debate in the European Union. We evaluated the effects of acute sublethal exposure to glyphosate on rainbow trout by measuring changes in their metabolic and hemato-immunologic functions and their ability to survive a viral challenge. Juvenile fish were exposed for 96 h to 500 μg L−1 of glyphosate through the active substance alone or two GHBs, Roundup Innovert® and Viaglif Jardin®, and fish were then infected with the infectious hematopoietic necrosis virus. Red and white blood cell counts (RBCC and WBCC), as well as several enzymatic activities (citrate synthase, CS; cytochrome-c oxidase, CCO; lactate dehydrogenase, LDH; glucose-6-phosphate dehydrogenase, G6PDH; acetylcholinesterase, AChE), were measured 96 h after chemical contamination (S1), and 96 h post-viral infection (S2). Mortality rates were monitored, and virus titers at the mortality peaks and seropositivity of the survivors were analyzed at 60 days post-viral infection (S3). Cumulative mortalities, viral titers, and seropositivity induced by virus infection were similar among conditions. Hematological analysis revealed significant increases of 30% for RBCC for Roundup at S1, and of 22% for WBCC at S2. No changes were observed in metabolic enzyme activities at S1. At S2, CCO and G6PDH activities were significantly higher than controls in all the chemically contaminated groups (+61 to 62% and +65 to 138%, respectively). LDH and AChE activities were increased for the Viaglif (p = 0.07; +55%) and for glyphosate and Roundup conditions (p

International audience; Electrochromic organic systems that can undergo substantial variation of their optical properties upon electron stimulus are of high interest for the development of functional materials. In particular, devices based on radical dimerization are appropriate because of the effectiveness and speed of the carbon-carbon bond making/breaking. Phenylmethylenepyrans are organic chromophores which are well suited for such purpose since their oxidation leads to the reversible formation of bispyrylium species by radical dimerization. In this paper, we show that the redox and spectroscopic properties of phenylmethylenepyrans can be modulated by adequate variation of the substituting group on the para position of the phenyl moiety, as supported by DFT calculations. This redox switching is reversible over several cycles and is accompanied by a significant modification of the UV-Vis spectrum of the chromophore, as shown by time-resolved spectroelectrochemistry in thin layer conditions.

International audience

The objective was to prospectively evaluate the application of intraoperative fluorescence imaging (IOFI) in the surgical excision of malignant masses in dogs, using a novel lipid nanoparticle contrast agent. Dogs presenting with spontaneous soft-tissue sarcoma or subcutaneous tumors were prospectively enrolled. Clinical staging and whole-body computed tomography (CT) were performed. All the dogs received an intravenous injection of dye-loaded lipid nanoparticles, LipImage 815. Wide or radical resection was realized after CT examination. Real-time IOFI was performed before skin incision and after tumor excision. In cases of radical resection, the lymph nodes (LNs) were imaged. The margin/healthy tissues fluorescence ratio or LN/healthy tissues fluorescence ratio was measured and compared with the histologic margins or LN status. Nine dogs were included. Limb amputation was performed in 3 dogs, and wide resection in 6. No adverse effect was noted. Fluorescence was observed in all 9 of the tumors. The margins were clean in 5 of 6 dogs after wide surgical resection, and the margin/healthy tissues fluorescence ratio was close to 1.0 in all these dogs. Infiltrated margins were observed in 1 case, with a margin/healthy tissues fluorescence ratio of 3.2. Metastasis was confirmed in 2 of 3 LNs, associated with LN/healthy tissues fluorescence ratios of 2.1 and 4.2, whereas nonmetastatic LN was associated with a ratio of 1.0. LipImage 815 used as a contrast agent during IOFI seemed to allow for good discrimination between tumoral and healthy tissues. Future studies are scheduled to evaluate the sensitivity and specificity of IOFI using LipImage 815 as a tracer.

Near-infrared (NIR) fluorescence imaging using FDA-approved indocyanine green (ICG) has been the subject of numerous studies during the past few years. It could constitute a potentially exciting new paradigm shift in veterinary oncology, especially to develop in vivo fluorescence imaging diagnostics and surgery guidance methods. The objective of this study was to evaluate the pharmacologic and toxicological characteristics in healthy beagle dogs of LipImage™ 815, a formulation made of NIR-dye-loaded lipid nanoparticles. The initial dosage for the evaluation of biodistribution was extrapolated from data in mice and then adapted to define the more adapted dose (MAD) according to the fluorescence results obtained in 5 dogs using a Fluobeam® 800 imaging device (phase 0 study). A single dose acute toxicity study was then performed (3 dogs, phase I study). Before the systemic administration of LipImage™ 815, the dogs presented a very mild residual fluorescence, particularly in the liver and kidneys. After injection, the plasma fluorescence continuously decreased, and the signal was relatively homogeneously distributed throughout the different organs, though more pronounced in the liver and to a lesser extent in the steroid-rich organs (adrenal, ovaries), intestines, lymph nodes and kidneys. A MAD of 2.0μg/kg was found. No evidence of acute or delayed general, hepatic, renal or hematologic toxicity was observed at 1-fold, 5-fold or 10-fold MAD. The results of this phase-0/phase-I study showed that an optimal dosage of LipImage™ 815 of 2.0μg/kg allowed the achievement of a fluorescence signal suitable for surgery guidance application without any acute side effects.

International audience; ObjectivesTo assess the efficacy of tocilizumab in patients with Takayasu arteritis (TA).MethodsWe conducted a retrospective multicenter study in 46 TA patients treated with tocilizumab. We analyzed factors associated with response to tocilizumab (assessed using NIH score).ResultsForty-six patients with TA were included, with a median age of 43 years [29–54], and 35 (76%) females. We observed a decrease in the median NIH scale (from 3 [2–3] at baseline to 0 [0–1] and 0 at 3 and 6 months, respectively; p

It is now well documented that several contaminants can modulate the fish immune system, leading to disrupted host resistance against pathogens and increased incidence of disease. Since fish are usually co-exposed to chemicals and pathogens in the natural environment, analysis of the immunotoxic effects of pollutants is particularly relevant. The authorities in the European Union have recommended the development of toxicity assays on cell cultures and embryos, as an alternative to testing in vertebrates. This is why in our study, a fish immune challenge assay was developed for the early life stages of Japanese medaka to evaluate and compare the relevance of new biomarkers. Fish were exposed to benzo[a]pyrene (BaP), a model pollutant, for 8 days at the embryonic stage, or for 48 h at the larvae and juvenile stages, and fish were infected with betanodavirus by bath-challenge of 106 TCID50/mL. Biometric changes and induction of malformations were observed after embryonic exposure. DNA damage and induction of EROD activity were recorded at the end of all chemical exposures. Viral infection increased the mortality rate significantly and disturbed the behavior of fish after light stimulation. While BaP exposure increased swimming speed, betanodavirus infection slowed swimming activity. In larvae co-exposed to BaP and the virus, the viral titer in the whole body was higher than in fish infected only with the virus. This study highlighted the sensitivity and usefulness of the immune challenge assay on the early life stages of Japanese medaka to evaluate the toxic effects of pollutants.

Mitochondrial metabolism is a tightly regulated process that plays a central role throughout the lifespan of hematopoietic cells. Herein, we analyze the consequences of the mitochondrial oxidative phosphorylation (OXPHOS)/metabolism disorder associated with the cell-specific hematopoietic ablation of apoptosis-inducing factor (AIF). AIF-null (AIF− /Y ) mice developed pancytopenia that was associated with hypocellular bone marrow (BM) and thymus atrophy. Although myeloid cells were relatively spared, the B-cell and erythroid lineages were altered with increased frequencies of precursor B cells, pro-erythroblasts I, and basophilic erythroblasts II. T-cell populations were dramatically reduced with a thymopoiesis blockade at a double negative (DN) immature state, with DN1 accumulation and delayed DN2/DN3 and DN3/DN4 transitions. In BM cells, the OXPHOS/metabolism dysfunction provoked by the loss of AIF was counterbalanced by the augmentation of the mitochondrial biogenesis and a shift towards anaerobic glycolysis. Nevertheless, in a caspase-independent process, the resulting excess of reactive oxygen species compromised the viability of the hematopoietic stem cells (HSC) and progenitors. This led to the progressive exhaustion of the HSC pool, a reduced capacity of the BM progenitors to differentiate into colonies in methylcellulose assays, and the absence of cell-autonomous HSC repopulating potential in vivo. In contrast to BM cells, AIF− /Y thymocytes compensated for the OXPHOS breakdown by enhancing fatty acid β-oxidation. By over-expressing CPT1, ACADL and PDK4, three key enzymes facilitating fatty acid β-oxidation (e.g., palmitic acid assimilation), the AIF− /Y thymocytes retrieved the ATP levels of the AIF +/Y cells. As a consequence, it was possible to significantly reestablish AIF− /Y thymopoiesis in vivo by feeding the animals with a high-fat diet complemented with an antioxidant. Overall, our data reveal that the mitochondrial signals regulated by AIF are critical to hematopoietic decision-making. Emerging as a link between mitochondrial metabolism and hematopoietic cell fate, AIF-mediated OXPHOS regulation represents a target for the development of new immunomodulatory therapeutics.

In this paper we describe the synthesis, the electrochemical behaviour as well as the linear and nonlinear optical (NLO) properties of two push-pull derivatives bearing pyranylidene electron donating fragment, pyrimidine/methyl pyrimidinium electron withdrawing moiety and a ferrocene part in the π-conjugated bridge. The properties of these two compounds were compared to their analogues without ferrocene or pyranylidene fragments. Experimental results were completed with DFT calculations to gain further insight into the intramolecular charge transfer (ICT). All the results indicate a significant charge transfer through the ferrocene unit. The ICT is however more limited than in all organic analogues.

International audience; The synthesis, thermal, electrochemical, and optical properties of a series of triphenylamine derivatives bearing pyridine fragments and their trifluoroacetate salts are described. A dramatic increase in the intramolecular charge transfer is observed upon protonation, as evidenced by a significant reduction in the HOMO-LUMO gap and a red shift of both the absorption and the emission band. White photoluminescence was obtained in solution by the controlled protonation of blue emitting pyridine derivatives, which resulted in the yellow-orange emissive acidified form. In the solid state the emission color of doped polystyrene thin films could be tuned from steel blue to lawn green when the ratio of the protonated form was increased. These compounds have potential applications in the fabrication of multi-color OLEDs based on only one material. © 2017 Elsevier Ltd

International audience; Inconsistent results have been reported regarding IL-5 blockade treatment in asthma. There were no direct between-treatment comparisons. Only differences between each drug and placebo were studied. We identified all RCTs with anti-IL5 treatments for patients with asthma over the 1990-September 2015 period. RCTs were searched on Medline, Cochrane and Embase. At least 50 patients were enrolled in each study. Outcomes considered were exacerbation rate reduction, FEV1 changes, ACQ-5 improvement, adverse events and serious adverse events. A global meta-analysis was first conducted followed by an indirect comparison of each IL-5-targeting drug: benralizumab, reslizumab and mepolizumab. Further eosinophilic subgroup analysis and sensitivity analysis were also conducted in case of heterogeneity. Ten trials involving 3421 patients were eligible for meta-analysis. IL-5 blockade significantly reduced annual exacerbation rates vs. placebo by 40% [29-50] (P < 0.01, I2 = 0.61). ACQ-5 was significantly improved vs. placebo but below the recognized MCID level (-0.31 [-0.41, -0.21], P < 0.01, I2 = 0.11). FEV1 changes from baseline were improved vs. placebo by 0.09 L [0.05-0.12] (P < 0.01, I2 = 0.28). The subgroup analysis identified a slight additional improvement in mean treatment effects in eosinophilic (> 300 mm3 /L) patients with severe asthma. Similar patterns and rates of adverse events and severe adverse events were reported with the three drugs. The data interpretations were not affected by the sensitivity analysis. IL-5 blockade appears to be a relevant treatment strategy to improve severe asthma management, particularly for eosinophilic patients. No clear superiority appeared between the drugs when appropriate doses were compared.

International audience; A series of new push-pull org. dyes incorporating a cyanoacrylic acid group as electron acceptor unit and α-chalcogenopyranylidene group (X = S; O) as electron donor unit has been synthesized, characterized and used as sensitizer for dye-sensitized solar cells (DSSCs). For the first time, α-pyranylidene and thiopyranylidene groups, have been evaluated in DSSC. To obtain the thermodn. values of the solar cell, an investigation of their electrochem. (CV) and optical properties (UV-vis absorption spectroscopy) is also reported.

Reactions of 4-amino TEMPO with alkynylmethoxy Fischer type carbene complexes lead to unknown transition organometallic nitroxide spin labels. According to the temperature and the nature of the aromatic group of the initial alkynyl carbene, Michael adducts and aminolysis products were obtained in various proportions. The reaction was extended to ferrocenyl carbene complexes to obtain novel organometallic spin systems containing two kinds of redox units. Their constitution is in agreement with IR, elemental analysis and mass spectrometry. Single X-ray diffraction has confirmed the molecular structure of the complexes and has showed the existence of intra and intermolecular hydrogen bonds. These air-stable paramagnetic carbenes have interesting redox behaviours and paramagnetic properties.

International audience; Over one year study (12 campaigns), particulate arsenic and dissolved inorganic arsenic (total inorganic Asi and arsenite As(III)) levels were determined along the whole salinity gradient of the Penzé estuary (12 stations) in Brittany (France). Concentrations, in the range 2-26 nM and 3-56 μg g− 1 for dissolved inorganic and particulate arsenic, respectively, were relatively high in comparison to pristine systems and were attributed to pig and poultry farming activities taking place in the catchment area. Our results show that variations of dissolved inorganic and particulate arsenic up to mid-estuary were significantly linked to fluvial inputs, these latter being controlled by water discharge and precipitations. Arsenite variations over a large salinity range (S > 4) were controlled by those of the marine end-member mainly through bacterial processes. Removal of dissolved species within the water column by adsorption on oxide material was found to be minimal while arsenic fluxes from the sediment control arsenate and arsenite levels in the upper part of the estuary.

International audience; A series of five octupolar molecules with central triphenylamine donor and peripheral diazine electron-withdrawing groups has been prepared. These structures possess extended π-spacer comprising multiple bonds in a combination with 1,4-phenylene and 2,5-thienylene subunits. Starting from tris(4-ethynylphenyl)amine, the key step in the preparation of the chromophores involves triple Sonogashira cross-coupling reaction. The photophysical properties of the compounds are described. A strong positive emission solvatochromism, typical for dyes featuring Intramolecular Charge Transfer (ICT), is observed, two-photon absorption (2PA) properties were also measured. Linear and nonlinear optical properties as well as electronic properties measured by cyclic voltametry and supported by DFT calculation were used to elucidate structure-property relationships

International audience; Fifteen new push-pull chromophores based on a proaromatic pyranylidene donor and its chalcogen analogues and various electron acceptor moieties were synthesized in a straightforward manner. These model molecules were designed and prepared to investigate the concept of proaromaticity as a tool to tune the fundamental properties of push-pull systems. All target chromophores with systematically varied structure were further investigated by electrochemistry, absorption spectra, and EFISH experiment in conjunction with DFT calculations. Employing structural variations such as chalcogen/acceptor replacement, extension of the π-system, and the position of substitution along the pyran ring, the HOMO-LUMO gap can be tuned within the range of 2.18 to 1.41 eV. A new and powerful electron withdrawing moiety, combining features of polarizable thiophene and successful indane-1,3-dione acceptor, cyclopenta[c]thiophen-4,6-dione (ThDione) has also been developed. © 2016 Elsevier Ltd

Dissolved arsenic is present in seawater at the 1 μg l−1 level in various chemical forms: mainly, As(III) and As(V) inorganic arsenic, MMA, DMA, and eventually, unknown organic compounds. The concentrations of the minor arsenic species are well below the detection limit of graphite furnace atomic absorption spectrometry (GFAAS). Therefore, a preconcentration/separation step is generally required before their determination. In this study, arsenic species were determined in seawater by flow injection hydride generation (FI-HG), collection within the graphite furnace, followed by atomic absorption spectrometry. This protocol permitted a preconcentration factor of about 1000 lowering the detection limit of arsenic in seawater to about 1.5 ng l−1 for a 10 ml sample volume under optimized experimental conditions. Based on the different responses of arsenic species towards hydride generation, an experimental protocol for arsenic speciation was proposed. Total arsenic could be determined after a thermal or a UV irradiation treatment in an alkaline persulfate medium after the conversion of all arsenic species to inorganic As(V). Total hydride-reactive species (As(III), As(V), monomethylarsenic (MMA) and dimethylarsenic (DMA)) could be determined for high NaBH4 and HCl concentrations because a similar analytical response was obtained for these individual species. As(III) could be determined alone by performing hydride generation in seawater at a pH of about 7–8. Non-hydride-reactive arsenic species were determined by the difference between total arsenic and hydride-reactive species. According to this analytical protocol, arsenic species were determined in reference estuarine and coastal seawaters. Hydride-reactive arsenic species were the major compounds, probably mainly As(V); this study tended also to confirm the presence of non-hydride-reactive organic species in seawater (15%). We also showed that As(III) was not stable in acidified seawater and was also slowly converted to As(V) in a coastal surface seawater at its natural pH. These results indicated that time and preservation conditions could severely modify the speciation of arsenic in seawater, particularly for the preservation of As(III).

International audience; In this study, direct determination of mercury at the nanogram per liter level in the complex seawater matrix by imaging time-resolved electrothermal atomization laser-excited atomic fluorescence spectrometry (ITR-ETA-LEAFS) is described. In the case of mercury, the use of a nonresonant line for fluorescence detection with only one laser excitation is not possible. For measurements at the 253.652 nm resonant line, scattering phenomena have been minimized by eliminating the simultaneous vaporization of salts and by using temporal resolution and the imaging mode of the camera. Electrothermal conditions (0.1 M oxalic acid as matrix modifier, low atomization temperature) have been optimized in order to suppress chemical interferences and to obtain a good separation of specific signal and seawater background signal. For ETA-LEAFS, a specific response has been obtained for Hg with the use of time resolution. Moreover, an important improvement of the detection limit has been obtained by selecting, from the furnace image, pixels collecting the lowest number of scattered photons. Using optimal experimental conditions, a detection limit of 10 ng L–1 for 10 μL of sample, close to the lowest concentration level of total Hg in the open ocean, has been obtained.

Thallium(I) has been added to estuarine sediment suspended in various natural and artificial aqueous samples in order to examine its reactivity under simulated estuarine conditions. In river water and sea water, adsorption of Tl to sediment was so rapid that a period of desorption–relaxation succeeded instantaneous adsorption. Entire time-courses could not be fitted with a conventional kinetic model, but pseudo-first-order forward and reverse rate constants of 0.0044 and 0.30 h −1 , respectively, were derived for river water by omitting measurements defining the adsorption “overshoot” observed at the onset of the experiment. The extent of adsorption after a 16 h equilibration period was considerably greater in river water than in sea water, and displayed a quasi-linear increase with increasing pH over the range 2–9 in the former but no clear dependence on pH in the latter. A logarithmic reduction in the sediment–water distribution coefficient, K D , was observed on estuarine mixing from river water to sea water. Experiments conducted in electrolyte solutions coupled with inorganic equilibrium speciation modeling revealed that the effect was the combined result of a reduction in the activity of Tl + , an increase in the proportion of TlCl 0 and increasing competition for adsorption sites from K + with an increase in salinity. Overall, there was little experimental evidence for either the oxidation of Tl + or its complexation by dissolved organic matter. The findings of the investigation are discussed in terms of the likely behavior of Tl in estuaries.

Methyl-, phenyl-, and n-butyltin trichloride RSnCl3 (R = Me, Ph, nBu) react selectivily with palladium(0)-phosphine precursors through the unprecedented oxidative addition of the Sn-C bond. With [Pd(2-PyPPh2)3] (2-PyPPh2=2-pyridyldiphenylphoshine), the reaction cleanly leads to stable cationic dichlorostannylene palladium complexes of the general formula trans-[PdR(SnCl2(2- PyPPh2)2)][X] (X = Cl, R = Me ([5]Cl), R = Ph ([6]Cl), R = nBu ([11]Cl); X = RSnCl4, R = Me ([5][MeSnCl4]), R=Ph ([6][PhSnCl4]), R=nBu ([11][nBuSnCl4])). The SnCl2(2-PyPPh2)2 fragment, formed by intramolecular coordination of the pyridyl groups to the dichlorostannylene moiety, can be considered as a self-assembled pincer-type ligand with a remarkable ability to suppress β-H elimination in its Pd-alkyl derivatives: [11][nBuSnCl4], containing a Pd-nBu moiety, was found to be stable up to 70 C. Oxidative addition of SnCl4 on [Pd(2-PyPPh2)3] resulted in trans-[PdCl(SnCl2(2- PyPPh2)2)]Cl ([7]Cl) and trans-[PdCl(SnCl3(2-PyPPh2)2)] (8). The molecular structure of 8 was determined by single-crystal X-ray crystallography, indicating that the Sn atom of the trichlorostannyl function has an octahedral coordination geometry. In contrast, oxidative addition of the Sn-Cbond of RSnCl3 on [Pd(PPh3)4] resulted in palladium trichlorostannyl complexes that were not stable toward cis-trans isomerization, (partial) elimination of SnCl2 (R=Me, Ph), or β-H elimination (R = nBu). The resulting mixtures of palladium alkyl and palladium hydride species were analyzed by multinuclear NMR, resulting in the identification of novel cis-[PdMe(SnCl3)(PPh3)2] (cis-4), trans-[PdMe(SnCl3)(PPh3)2] (trans-4), and cis-[PdH(SnCl3)(PPh3)2] (cis-10) along with previously observed trans-[PdPh(Cl)(PPh3)2] (1), trans-[PdMe(Cl)(PPh3)2] (3), trans-[PdH(SnCl3)(PPh3)2] (trans-10), and trans-[PdH(Cl)(PPh3)2] (9).

International audience; This study examined the potential metal pollution induced by the accidental spill of different acids into seawater. The acids sink to the bottom according to their densities and subsequently react with marine sediments. The acids selected for this study were acetic, hydrochloric, nitric, sulfuric, and phosphoric acids; the metallic elements selected were Cr, Cu, Fe, Mn, Pb and Zn. The sediment was collected in Brest Harbour. The percentages of metals released from this sediment in the presence of various concentrations of acids in seawater were important; concentrations of approximately 7 mg L(-1) for Mn and 60 mg L(-1) for Zn were observed under our experimental conditions. We also examined the rate of release of these metals from the sediment into the seawater in the presence of the different acids and under different experimental conditions. We found that most of the metallic elements were released from the sediments into the seawater during the first fifteen minutes of exposure. After this time, a high degree of pollution was induced if acids leached into seawater were not rapidly diluted.

International audience; Coal is currently becoming an increasingly interesting fossil energy resource and that is the reason why its maritime transport, and hence the risk of collier accidents, increase. In this work, the environmental impact of an accidental coal immersion at sea is studied: the physicochemical effects are estimated using innovative experimental setups--a laboratory seawater canal called "polludrome" is used to evaluate the behaviour of coal particles submitted to a seawater flow, and a specifically designed tub is used to study the physicochemical consequences induced when coal is introduced into continuously renewed seawater. When coal is introduced into seawater, the most easily visible consequences are physical: fine coal particles reduce the daylight penetration up to 100% and move along with the flow, and coal chunks accumulate on the floor. Chemical effects are also measured: humic matters are dissolved from coal into seawater (up to 2 mg L(-1)), but no release of polycyclic aromatic hydrocarbons is evidenced. Some inorganic compounds are dissolved, among which manganese, whose concentrations can reach 1 microg L(-1). Fortunately, the results show that the environmental impact of this type of accident would remain limited.

International audience; White photoluminescence both in soln. and the solid-state was obtained by the controlled protonation of a blue emitting 4,6-bis(arylvinyl)pyrimidine, which resulted in the formation of an orange emissive acidified form. This dye has potential applications in the fabrication of white OLEDs based on only one material.

Attempts at methylating cis -[Mo 2 Cp 2 (μ-SMe) 3 L 2 ](BF 4 ) [Cp = η 5 -C 5 H 5 ; L = CO ( 1a ) CNxyl ( 1b ), CNBu t ( 1c ), NCMe ( 1d )] with methyl triflate gave the corresponding thioether-bridged cations [Mo 2 Cp 2 (μ-SMe) 2 (μ-SMe 2 )L 2 ] 2+ ( 4 2+ ), except in the case of 1a which did not react at room temperature. The electronic properties of the ancillary ligands L thus have a crucial influence on the course of this reaction. The dimeric compounds [Mo 2 Cp 2 (μ-SMe) 3 (CNBu t )(CN)] ( 2 ) and [Mo 2 Cp 2 (μ-SMe) 3 {μ-η 1 -N C(CH 3 )CH 2 CN}] ( 3 ), which potentially offer the alternatives of S- or N-methylation, reacted with methylating agents to give mainly the S-methylated derivatives 5 and 7 . Only in the case of the nucleophilic reactant 2 was N-methylation also observed and isomer 6 was obtained as a minor product together with 5 . New complexes have been completely characterised by multinuclear NMR, IR and elemental analysis, supplemented for 5 by X-ray diffraction study at 100 K.

cited By 10; International audience; A series of chemical and electrochemical transformations of systems in which a Mo2Cp2(μ-SMe)3 core is bridged by a μ-C2HnR ligand (n = 0-4) are described in this paper. The reaction of the alkylidene complex [Mo2Cp2(μ-SMe) 3(μ-η1:η2-CHCH2Tol)] (BF4) (1) with LiBun at 0°C produces the μ-σ,π-vinyl complex [Mo2Cp2(μ-SMe) 3(μ-η1:η2-CH=CHTol] (2) in good yield. The molecular structure of 2 has been confirmed by X-ray analysis. Upon treatment with NaBEL4 1 is readily converted into the semibridging alkyl species [Mo2Cp2(μ-SMe)3(μ-CH 2CH2Tol)] (3), which is also formed by electrochemical reduction of 1 in acidic medium. NMR and X-ray diffraction studies of 3 are consistent with, but do not definitively establish, the presence of a η1 α-agostic interaction. Density functional theory has been used to confirm the presence of agostic interactions in both 1 and 3 and also to explore the exchange pathways for these hydrocarbyl dimolybdenum systems. Electrochemical transformation of the μ-alkylidene complex 1 gives 3 as the major product when acid is present and a mixture of 2 and 3 when acid is absent, production of 2 being favored by low initial concentrations of 1. Theoretical, spectroscopic, and diffraction data are used to explain the formation and structures of closely related [Mo2Cp 2(μ-SMe)3(μ-C2HnR] z- complexes (n = 0-4 and z = 0, 1), including 1-3. © 2005 American Chemical Society.

The antiangiogenic extracellular matrix protein thrombospondin-1 (TSP-1) inhibits tumor growth and metastasis in animals. However, the clinical relevance of such findings are equivocal as increased stromal TSP-1 expression has been associated with either good or poor prognosis. In an effort to obtain a more integrated understanding of the role of TSP-1 in breast cancer, we first used a breast tumorigenesis model in which tumor-associated stromal fibroblasts were engineered to produce high levels of TSP-1. We demonstrate here that stromal TSP-1 delayed human MDA-MB-231/B02 breast tumor growth. However, this delay in MDA-MB-231/B02 tumor growth upon exposure to TSP-1 was associated with an increased vascular endothelial growth factor (VEGF) expression in tumor cells themselves, leading to a tumor growth rate comparable to that of tumors whose fibroblasts did not overproduce TSP-1. Clinical evidence also suggested that primary breast carcinomas have adapted to escape the effects of stromal TSP-1. TSP-1 was found to be expressed in the stroma of human breast carcinomas where, although its level correlated with decreased vascularization, it was unexpectedly associated with a reduction of relapse-free survival. In metastatic axillary lymph nodes, tumor cells expressed high levels of VEGF and TSP-1 expression were no longer associated with a decreased vascularization. Overall, these results suggest that a resistance may develop early in human breast cancers as a result of high in situ exposure to stromal TSP-1, leading to disease progression.

The treatment of a rejection of tannery effluent was carried out on an organic nanofiltration membrane. The rejection was recovered from a leather manufacturing plant in the area of Algiers (Rouiba). The effluent of the bath of tanning and liming charged with chromium ions was the subject of this study. In the case of synthetic solutions, the experimental variations of the retention ranged from 94–99.9% depending on initial feed concentration. For the tanning bath, the results indicated that chromium retentions of 60 and 30% were observed respectively in acid and basic medium. In acid medium, the rejection of the bath of liming has generated a retention of 15%. The use of the model of Nakao et al. [1] based on the extended modified Nernst Planck equation enabled us to compare the theoretical retention of chromium ions with the experimental results and to calculate the membrane pore radius.

This study is focused on the influence of the nature of the water to be treated on the efficiency of nitrate elimination by a commercial membrane. By gradually increasing the complexity of the treated solutions (binary, ternary mixtures and then natural waters), we identified the physical, chemical and electric phenomena, which govern the ion transfer. We highlighted the influence on the membrane selectivity of the hydration energy of the solute, of the membrane-solute and solute-solute interactions. The observations made with simple nitrated solutions (binary and ternary) were extrapolated and confirmed in experiments on the water doped out of nitrates.

Mechanism specificity of ion separations in drinking water is necessary for the study of modeling transfer of calcium salt through nanofiltration membrane. In the present work, we have investigated a mathematical model which can specify the transfer phenomena of solute through a nanofiltration membrane and to predict its reject. The proposed model is based on the extended equation of Nernst-Planck. It is characterized by constants called transfer parameters, which have been determined according to the composition of the initial solution as a binary or a ternary mixture. The established model permitted us to predict the retention of calcium salt. The result of the application of the model has shown that there is a good agreement between the theoretical and experimental curves.

Based on the model initially proposed for nanofiltration combining the modified equation of Nernst–Plank and the film theory, expressions were developed to allow accurate characterization of solute transports during nanofiltration. In nanofiltration, the solute concentration in the feed solution is one of the factors which have an effect on solute rejection. So, it was important to study the effect of solute concentration on these transport parameters. In this approach, the model transport parameters, K eff and Φ have been related to the feed solution concentration. While serving to us as the equilibrium equations of Donnan and that of Kirianov, we have established relations between these parameters of transport to the concentration of the feed aqueous solutions. Both the effective transfer coefficient and the transmittance increase when concentration increases. The relations describe our experimental results satisfactorily. They have also allowed us the determination of the order of the charge density of the membrane. It was found to be 8.57×10 −4 and 49.5×10 −4 equivalent mol l −1 which correspond to −33 and −191 mC m −2 , respectively for a 0.4 μm membrane thickness.

The paper investigates the characteristics of microwave transmission in coplanar waveguides (CPWs) fabricated on various silicon carbide substrates. Propagation constant and characteristic impedance measurements were performed at frequencies from 0.1 to 10 GHz. Different propagation modes are observed as a function of frequency and substrate resistivity. In the case of the low-loss structure, a quasi-TEM equivalent circuit model was developed from the available process parameters, taking into account the effects of electromagnetic fields in CPW structures.

International audience; Spectroscopic and electrothermal conditions for the determination of antimony in seawater using a transversely heated graphite furnace with Zeeman-effect background correction have been optimized with the use of an a priori calculation of the detection limit. The lowest limit of detection was obtained with a 2 nm spectral curvatures bandwidth and the use of an electrodeless discharge lamp; however, these experimental conditions resulted in strong premature curvature of calibration curves. Pd(NO3)2 can be recommended as a chemical modifier because seawater interference effects are minimized and pretreatment curves up to 1500°C can be used permitting the removal of the major part of the saline matrix before atomization. Under optimized spectroscopic and electrothermal conditions the obtained limit of detection of Sb in seawater was about 0.4 μg L-1.

International audience; High concentration of added hydrogen fluoride converted the seawater chloride to the corresponding fluoride matrix, and the liberated hydrochloric acid could be removed during the drying step. The atomization of cadmium and lead could be performed at a relatively low temperature (∼1300°C) at which the vaporization of the fluoride matrix was relatively slow, and the corresponding weak background signals could be separated from the analytical signals in time. Experimental conditions for the determination of Cd and Pb in seawater in the presence of HF were optimized with the use of the a priori calculation of the limit of detection. The experimental limit of detection obtained for Cd and Pb were, respectively, 0.007 and 0.25 μg l-1 for a 15-μl seawater sample (3σ, 20 replicates). The concentrations of Cd determined in a SLEW-1 estuarine water and a CASS-2 seawater were 0.020±0.002 and 0.016±0.002 μg l-1 Cd, respectively, in good agreement with the 0.018±0.003 and 0.019±0.004 μg l-1 Cd certified values (At the 95% confident level, 10 replicates). © 2002 Elsevier Science B.V. All rights reserved.

Various novel dipolar V-shaped chromophores are prepared via condensation of methylenepyran aldehydes and methylpyrimines.

Wild freshwater eel populations have dramatically declined in recent past decades in Europe and America, partially through the impact of several factors including the wide spread of infectious diseases. The anguillid rhabdoviruses eel virus European X (EVEX) and eel virus American (EVA) potentially play a role in this decline, even if their real contribution is still unclear. In this study, we investigate the evolutionary dynamics and genetic diversity of anguiillid rhabdoviruses by analysing sequences from the glycoprotein, nucleoprotein and phosphoprotein (P) genes of 57 viral strains collected from seven countries over 40 years using maximum-likelihood and Bayesian approaches. Phylogenetic trees from the three genes are congruent and allow two monophyletic groups, European and American, to be clearly distinguished. Results of nucleotide substitution rates per site per year indicate that the P gene is expected to evolve most rapidly. The nucleotide diversity observed is low (2–3 %) for the three genes, with a significantly higher variability within the P gene, which encodes multiple proteins from a single genomic RNA sequence, particularly a small C protein. This putative C protein is a potential molecular marker suitable for characterization of distinct genotypes within anguillid rhabdoviruses. This study provides, to our knowledge, the first molecular characterization of EVA, brings new insights to the evolutionary dynamics of two genotypes ofAnguillid rhabdovirus, and is a baseline for further investigations on the tracking of its spread.

Reaction of [PdClMe(P^N)2] with SnCl2 followed by Cl-abstraction leads to apparent Pd-C bond activation, resulting in methylstannylene species trans-[PdCl{(P^N)2SnClMe}][BF4] (P^N = diaryl phosphino-N-heterocycle). In contrast, reaction of Pt analogues with SnCl2 leads to Pt-Cl bond activation, resulting in methylplatinum species trans-[PtMe{(P^N)2SnCl2}][BF4]. Over time, they isomerise to methylstannylene species, indicating that both kinetic and thermodynamic products can be isolated for Pt, whereas for Pd only methylstannylene complexes are isolated. Oxidative addition of RSnCl3 (R = Me, Bu, Ph) to M(0) precursors (M = Pd or Pt) in the presence of P^N ligands results in diphosphinostannylene pincer complexes trans-[MCl{(P^N)2SnCl(R)}][SnCl4R], which are structurally similar to the products from SnCl2 insertion. This showed that addition of RSnCl3 to M(0) results in formal Sn-Cl bond oxidative addition. A probable pathway of activation of the tin reagents and formation of different products is proposed and the relevancy of the findings for Pd and Pt catalysed processes that use SnCl2 as a co-catalyst is discussed.

International audience; Thirteen novel dipolar and V-​shaped chromophores with pyranylidene electron-​donating part, diazine electron-​withdrawing part and various π-​linkers were synthesized. The extent of intramol. charge transfer, structure-​property relationships and optical properties were further investigated by UV​/Vis absorption, electrochem., and DFT calcns.