27 research outputs found

    European Jurassic floras : statistics and palaeoenvironmental proxies

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    The Jurassic floras of Europe show considerable diversity. To examine the extent of this diversity and its possible causes we used multivariate statistical methods (cluster analysis, PCA, NMDS) to compare all significant Jurassic floras in Europe. Data were based on 770 taxa from 46 fossiliferous occurrences (25 units) from France, Germany, Greenland, Hungary, Italy, Norway, Poland, Romania, Scotland, Serbia, Sweden, Switzerland, and the United Kingdom. Statistical analyses were applied at species level and genus level, and also performed for the major plant groups. The genus cladograms show affinities between different localities based on environmental factors, while the cladograms based on species affinities indicate only taxonomical correlations. The study shows that locality age does not seem to be of paramount importance for floral composition

    "Smart" molecular engineering of metallomesogens based on Pt(II) terpyridine coordination complexes

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    A series of ionic tetracoordinated Pt(II) complexes based on terpyridine ligand were synthesized and characterized. Their chemical structures were engineered by using counterions of different coordination strengths and dimensions, namely non-coordinating BF4, weakly coordinating bulky gallate units, and small and strongly coordinating chlorine (Cl). The complexes containing lipophilic gallate units exhibit low temperature liquid crystalline properties. The mesomorphic properties were investigated by polarized optical microscopy (POM), differential scanning calorimetry (DSC) and X-ray diffraction studies (SWAXS). Photophysical properties were determined in solution and condensed states

    Emissive Zn(II) metallomesogen based on tridentate terpyridine ligand

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    A low temperature liquid crystal based on luminescent terpyridine Zn(II) complex is presented. The induction of the mesomorphic properties was achieved using a lipophilic gallate unit as ancillary ligands. The mesomorphic properties were investigated by polarised optical microscopy (POM), differential scanning calorimetry (DSC), thermogravimetric analysis (TA) and X-ray scattering (SWAXS) of bulk materials, while the optical properties of the complex were investigated in solution and in condensed liquid crystalline states

    Synthesis and characterization of homogeneous (U,Am)O₂ and (U,Pu,Am)O₂ nanopowders

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    This paper details the first dedicated production of homogeneous nanocrystalline particles of mixed actinide oxide solid solutions containing americium. The target compositions were U0.75Pu0.20Am0.05O2U_{0.75}Pu_{0.20}Am_{0.05}O_{2}, U0.90Am0.10O2U_{0.90}Am_{0.10}O_{2} and U0.80Am0.20O2U_{0.80}Am_{0.20}O_{2}. After successful hydrothermal synthesis and chemical characterisation, the nanocrystals were sintered and their structure and behaviour under self-irradiation were studied by powder XRD. Cationic charge distribution of the as-prepared nanocrystalline and sintered U0.80Am0.20O2U_{0.80}Am_{0.20}O_{2} materials was investigated applying UM4U M_{4} and AmM5Am M_{5} edge high energy resolution XANES (HR-XANES). Typical oxidation states detected for the cations are U(IV)/U(V)U_{(IV)}/U_{(V)} and Am(III)/Am(IV)Am_{(III)}/Am_{(IV)}. The measured crystallographic swelling was systematically smaller for the as-synthesised nanoparticles than the sintered products. For sintered pellets, the maximal volumetric swelling was about 0.8% at saturation, in line with literature data for PuO2PuO_{2}, AmO2AmO_{2}, (U,Pu)O2(U,Pu)O_{2} or (U,Am)O2(U,Am)O_{2}

    Design and baseline characteristics of the finerenone in reducing cardiovascular mortality and morbidity in diabetic kidney disease trial

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    Background: Among people with diabetes, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality and progression of their underlying kidney disease. Finerenone is a novel, nonsteroidal, selective mineralocorticoid receptor antagonist that has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD) while revealing only a low risk of hyperkalemia. However, the effect of finerenone on CV and renal outcomes has not yet been investigated in long-term trials. Patients and Methods: The Finerenone in Reducing CV Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important CV and renal outcomes in T2D patients with CKD. FIGARO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 6 years. FIGARO-DKD randomized 7,437 patients with an estimated glomerular filtration rate >= 25 mL/min/1.73 m(2) and albuminuria (urinary albumin-to-creatinine ratio >= 30 to <= 5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of the primary outcome (overall two-sided significance level alpha = 0.05), the composite of time to first occurrence of CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure. Conclusions: FIGARO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of CV and renal events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen. Trial Registration: EudraCT number: 2015-000950-39; ClinicalTrials.gov identifier: NCT02545049

    A palaeoenvironmental reconstruction of the Middle Jurassic of Sardinia (Italy) based on integrated palaeobotanical, palynological and lithofacies data assessment

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    During the Jurassic, Sardinia was close to continental Europe. Emerged lands started from a single island forming in time a progressively sinking archipelago. This complex palaeogeographic situation gave origin to a diverse landscape with a variety of habitats. Collection- and literature-based palaeobotanical, palynological and lithofacies studies were carried out on the Genna Selole Formation for palaeoenvironmental interpretations. They evidence a generally warm and humid climate, affected occasionally by drier periods. Several distinct ecosystems can be discerned in this climate, including alluvial fans with braided streams (Laconi-Gadoni lithofacies), paralic swamps and coasts (Nurri-Escalaplano lithofacies), and lagoons and shallow marine environments (Ussassai-Perdasdefogu lithofacies). The non-marine environments were covered by extensive lowland and a reduced coastal and tidally influenced environment. Both the river and the upland/hinterland environments are of limited impact for the reconstruction. The difference between the composition of the palynological and palaeobotanical associations evidence the discrepancies obtained using only one of those proxies. The macroremains reflect the local palaeoenvironments better, although subjected to a transport bias (e.g. missing upland elements and delicate organs), whereas the palynomorphs permit to reconstruct the regional palaeoclimate. Considering that the flora of Sardinia is the southernmost of all Middle Jurassic European floras, this multidisciplinary study increases our understanding of the terrestrial environments during that period of time

    Hetero-Bimetallic Ferrocene-Containing Zinc(II)-Terpyridyl-Based Metallomesogen: Structural and Electrochemical Characterization

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    The synthesis, as well as the mesomorphic and electrochemical properties, of a hetero-bimetallic coordination complex able to self-assemble into a columnar liquid crystalline phase is reported herein. The mesomorphic properties were investigated by polarized optical microscopy (POM), differential scanning calorimetry (DSC) and Powder X-ray diffraction (PXRD) analysis. Electrochemical properties were explored by cyclic voltammetry (CV), relating the hetero-bimetallic complex behaviour to previously reported analogous monometallic Zn(II) compounds. The obtained results highlight how the presence of the second metal centre and the supramolecular arrangement in the condensed state pilot the function and properties of the new hetero-bimetallic Zn/Fe coordination complex

    Role of the Environment Polarity on the Photophysical Properties of Mesogenic Hetero-Polymetallic Complexes

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    New hetero-polynuclear coordination complexes based on a pentacoordinated Zn(II) metal center with tridentate terpyridine-based ligands and monoanionic gallates functionalized with long alkyl chains containing ferrocene units were designed, synthesized and characterized using spectroscopic and analytical methods. The complexes are mesomorphic, exhibiting columnar hexagonal mesophases. The photophysical properties in a solution and in an ordered condensed state were accurately investigated and the influence of the polarity of the solvent was evidenced

    Synthesis and characterization of nanocrystalline U1-xPuxO2(+y) mixed oxides

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    We report here the first synthesis of mixed oxide U1-xPuxO2(þy) nanoparticles. The obtained nanopowders were characterized by X-ray diffraction, thermal ionization mass spectrometry, transmission electron microscopy, Raman spectroscopy, and U M4 edge high-energy-resolution X-ray absorption near edge structure (HR-XANES). The HR-XANES spectra give evidence for the partial oxidation of UIV to UV. This novel route toward the formation of actinide-actinide solid solution opens research opportunities that are not accessible using bulk materials. We give details on the X-ray diffraction study on plutonium oxalate hexahydrate, as a reagent for the synthesis of such nanoparticles.JRC.G.I.3-Nuclear Fuel Safet
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