Entwined dimer formation from self-complementary bis-acridiniums

International audienceThe self-assembling entwined dimer of a bis-acridinium tweezer has been investigated in organic and aqueous media. Please check this proof carefully. Our staff will not read it in detail after you have returned it. Please send your corrections either as a copy of the proof PDF with electronic notes attached or as a list of corrections. Do not edit the text within the PDF or send a revised manuscript as we will not be able to apply your corrections. Corrections at this stage should be minor and not involve extensive changes. Proof corrections must be returned as a single set of corrections, approved by all co-authors. No further corrections can be made after you have submitted your proof corrections as we will publish your article online as soon as possible after they are received. Please ensure that: The spelling and format of all author names and affiliations are checked carefully. You can check how we have identified the authors' first and last names in the researcher information table on the next page. Names will be indexed and cited as shown on the proof, so these must be correct

Semi-automatic Liver Tumor Segmentation in Dynamic Contrast-Enhanced CT Scans Using Random Forests and Supervoxels

International audiencePre-operative locoregional treatments (PLT) delay the tumor progression by necrosis for patients with hepato-cellular carcinoma (HCC). Toward an efficient evaluation of PLT response, we address the estimation of liver tumor necrosis (TN) from CT scans. The TN rate could shortly supplant standard criteria (RECIST, mRECIST, EASL or WHO) since it has recently shown higher correlation to survival rates. To overcome the inter-expert variability induced by visual qualitative assessment, we propose a semi-automatic method that requires weak interaction efforts to segment parenchyma, tumoral active and necrotic tissues. By combining SLIC supervoxels and random decision forest, it involves discriminative multi-phase cluster-wise features extracted from registered dynamic contrast-enhanced CT scans. Quantitative assessment on expert groundtruth annotations confirms the benefits of exploiting multi-phase information from semantic regions to accurately segment HCC liver tumors

1907 : Société d’Histoire de Saverne

En 2007, la Société d’histoire et d’archéologie de Saverne et environs peut fêter ses cent ans d’existence. C’est sans doute l’occasion de faire un rappel de l’histoire et un bilan des activités de la SHASE, abréviation de l’intitulé de cette association bien connue de ses familiers. Pour établir l’historique de la SHASE et tirer un tableau succinct de ses réalisations dans le domaine de la connaissance du passé local, nous disposons des statuts administratifs déposés par l’association auprès..

LCA of perennial crops: implications of modeling choices through two contrasted case studies

International audienceAs highlighted in several recent reviews, there is a need to harmonize the way LCA of perennial crops is conducted (Bessou et al. 2013; Cerutti et al. 2013). In most published LCA on perennial crops, the agricultural production is based on data sets for just one productive year. This may be misleading since performances and impacts of the system may greatly vary year by year and the evolution of the stand over the cycle induces specific mechanisms (nutrient re-mobilization, yield alternating, resistance etc.) that must be included. Without a proper mechanistic model, the only way to account for such phenomena is to wider the data sets to at least account for each stage of the stand development and, if possible, all years of the crop cycle. Three modeling choices for the perennial crop cycle were tested in parallel in two contrasted LCA case studies: oil palm fruits from Indonesia, and small citrus from Morocco. Modeling choices tested were: i) a chronological modeling over the complete crop cycle of orchards (Bessou et al. 2013), ii) a three years average from the productive phase and iii) a selection of different single years from the productive phase. In both case studies, the system boundary included all processes from the seed production until the harvested fruits at farm-gate. The functional unit was 1 kg of fresh fruits. The chosen approach to model the perennial cycle influences the final results and deserves specific attention

Synthesis, electronic and photophysical properties of a bisacridinium-Zn(II) porphyrin conjugate

The synthesis of a novel bisacridinium-Zn(II) porphyrin is reported and its properties investigated via electrochemical, photophysical and computational studies. Cyclic voltammetry studies revealed a two-electron oxidation of the Zn(II) porphyrin and the simultaneous one electron reductions of the two acridiniums. Using absorption, emission and ultrafast transient absorption spectroscopies, the near total fluorescence quenching observed following excitation of either the acridinium or Zn(II) porphyrin units was assigned to ultrafast electron transfer (${\le }0.3$ ps) leading to a reduced acridinium and an oxidized porphyrin unit in the bisacridinium-Zn(II) porphyrin conjugate. In addition, computational studies were found to complement experimental results, with calculations revealing two near degenerate HOMOs for the porphyrin

Synthesis, electronic and photophysical properties of a bisacridinium-Zn(II) porphyrin conjugate

The synthesis of a novel bisacridinium-Zn(II) porphyrin is reported and its properties investigated via electrochemical, photophysical and computational studies. Cyclic voltammetry studies revealed a two-electron oxidation of the Zn(II) porphyrin and the simultaneous one electron reductions of the two acridiniums. Using absorption, emission and ultrafast transient absorption spectroscopies, the near total fluorescence quenching observed following excitation of either the acridinium or Zn(II) porphyrin units was assigned to ultrafast electron transfer (${\le }0.3$ ps) leading to a reduced acridinium and an oxidized porphyrin unit in the bisacridinium-Zn(II) porphyrin conjugate. In addition, computational studies were found to complement experimental results, with calculations revealing two near degenerate HOMOs for the porphyrin

Self-Complementary and Narcissistic Self-Sorting of bis-Acridinium Tweezers

International audienceA molecular tweezer incorporating two acridinium moieties linked by a 1,3-dipyridylbenzene spacer was synthesized in three steps. The formation of its self-complementary dimer in water was demonstrated as the result of pi-pi stacking and hydrophobic interactions. Moreover, a 1:1 mixture of this bis-acridinium tweezer with one build on a 2,6-diphenylpyridyl spacer evidenced a narcissistic self-sorting behaviour in water

Effects on mollicutes (wall-less bacteria) of synthetic peptides comprising a signal peptide or a membrane fusion peptide, and a nuclear localization sequence (NLS) – a comparison with melittin

AbstractIn order to investigate the effect of primary amphipathic peptides on mollicutes (wall-less bacteria), we have synthesised five molecules (P1, P2, P3, JM123, and JM133) comprising a 16 to 18-residue hydrophobic sequence and the nuclear localization sequence (NLS) PKKKRKV of simian virus 40 large-T antigen, C-terminated by a cysteamide group. The hydrophobic cluster was in P1 the signal sequence of the heavy chain of Caiman crocodilus immunoglobulin G and in JM123 the fusion peptide of human immunodeficiency virus 1 glycoprotein gp41 in which phenylalanine7 was replaced by a tryptophan residue. The homologues P2, P3, and JM133 were obtained by slight alterations of these sequences. Circular dichroism spectroscopy revealed that, in liposomes, P-series peptides were mainly under the form of β-sheets whereas JM-series peptides displayed a high proportion of turns. These peptides proved to be bactericidal for some mollicutes, notably Acholeplasma laidlawii, but were much less potent than melittin. Furthermore, their antibiotic activity was independent of the average thickness of the plasma membrane hydrophobic core whilst that of melittin was inversely related to the thickness. Melittin and the synthetic peptides abolished spiroplasma cell motility and helicity, but only melittin and P-series peptides split the cells into globular forms displaying an average diameter of ca. 1 μm. In contrast to melittin, the synthetic peptides agglutinated spiroplasmas, suggesting that their polycationic NLS was exposed on the cell surface. P-series peptides decreased, though less efficiently than melittin, A. laidlawii and Spiroplasma melliferum membrane potential (ΔΨ) and transmembrane pH gradient (ΔpH), at concentrations much lower than their minimal inhibitory concentrations whilst JM-series peptides had no effect on ΔΨ and ΔpH in the same conditions. Actually, the bactericidal activity of these peptides towards mollicutes was proportional to their ability to collapse the electrochemical transmembrane potential

Long-term superpixel tracking using unsupervised learning and multi-step integration

International audienceIn this paper, we analyze how to accurately track superpixels over extended time periods for computer vision applications. A two-step video processing pipeline dedicated to long-term superpixel tracking is proposed based on unsupervised learning and temporal integration. First, unsupervised learning-based matching provides superpixel correspondences between consecutive and distant frames using context-rich features extended from greyscale to multi-channel. Resulting elementary matches are then combined along multi-step paths running through the whole sequence with various inter-frame distances. This produces a large set of candidate long-term superpixel pairings upon which majority voting is performed. Video object tracking experiments demonstrate the efficiency of this pipeline against state-of-the-art methods