160 research outputs found

    Extended benzodifuran-furan derivatives as example of pi-conjugated materials obtained from sustainable approach

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    The synthesis of extended benzodifuran-furan systems are described as an example of pi-conjugated materials prepared by following a green approach with only water being produced as waste and using furan derivatives from renewable sources. Investigation of their optical and electrochemical properties shows that the new compounds present electronic properties compatible for application in organic electronics. (C) 2012 Elsevier Ltd. All rights reserved

    Rational Topological Design for Fluorescence Enhancement upon Aggregation of Distyrylfuran Derivatives

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    A series of 2,5-distyrylfuran derivatives bearing pentafluorophenyl- and cyanovinyl units have been synthesized for aggregation-induced emission (AIE). The effect of the type and extent of the supramolecular connections on the AIE of the furan derivatives were examined and correlated with their X-ray crystal structures. It was found that the simultaneous presence of cyano and perfluorophenyl units strongly enhances the fluorescence upon aggregation. Single-crystal X-ray diffraction analysis confirmed that C — H⋅⋅⋅F, F⋅⋅⋅F, C — H⋅⋅⋅nitrile, Ar⋅⋅⋅ArF (Ar=aryl, ArF=fluoroaryl), and nitrile⋅⋅⋅ArF intra- and intermolecular interactions drive the topology of the molecule and that solid-state supramolecular contacts favor AIE of the furan derivatives

    Syntheses and NMR and XRD studies ofcarbohydrate–ferrocene conjugates

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    Carbohydrate–ferrocene conjugates were synthesized and showed that the ferrocene entity appeared to be confined to a low volume so that proton NMR spectroscopy revealed 3 to 4 signals for substituted cyclopentadienyl instead of two usually

    Decision-Making Measured by the Iowa Gambling Task in Patients with Alcohol Use Disorders Choosing Harm Reduction versus Relapse Prevention Program

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    AIMS: Two main therapeutic programs were offered to patients suffering from alcohol use disorders (AUDs): avoid the alcohol by abstinence or controlling their consumption. After information and motivational sessions, the patient chooses his own therapeutic plan. However, patients with AUD exhibit poor decision-making. The purpose of this study was to investigate the decision-making in AUD by comparing patients who chose to reduce and control their consumption to those who chose abstinence program. METHODS: Sixty-seven subjects with alcohol use disorder were included (AUD group) for treatment, choosing either a relapse prevention program (RPP) or a harm reduction program (HRP). Patients were compared to a healthy control group (n = 31). Cognitive skills were assessed through the Montreal Cognitive Assessment test, the National Adult Reading Test, the Trail Making Test and the Iowa Gambling Task (IGT). RESULTS: Thirty-seven patients with AUD chose the RPP while 30 followed a HRP. The AUD group performed worse than controls on the IGT. The RPP group had significantly lower performance than both HRP and control groups (these later groups being not statistically different). No correlation was observed between the available clinical, cognitive and intellectual measures. CONCLUSION: This study confirms that the decision-making process of patients with an alcohol use disorder is impaired. However, the 2 groups differ on the IGT scores, despite comparable clinical and cognitive profiles. The patients\u27 decision-making abilities could be a useful guide when developing therapeutic programs

    Synthesis, electronic properties and packing modes of conjugated systems based on 2,5-di(cyanovinyl)furan or thiophene and imino-perfluorophenyl moieties

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    The synthesis, the electronic properties and the solid state arrangements of conjugated systems associating pentafluorophenyl units linked via azomethine bonds to a central 2,5-di(cyanovinyl)-thiophene or furan moieties have been investigated. The crystal structures of the two compounds are analyzed in terms of intermolecular interactions involving hydrogen and halogen bonding, pi-pi stacking and donor-acceptor interactions. Both structures reveal similar pi-stacking of the molecules with nevertheless a more compact packing mode for the furan derivative. Moreover this structure is stabilized by several F center dot center dot center dot F interactions between the columns of molecules. By contrast for the thiophene derivative, the structure requires the insertion of CH2Cl2 to be stabilized via Cl center dot center dot center dot F interactions

    L’anesthésie topique sans recours à un médecin anesthésiste dans la chirurgie de la cataracte ambulatoire de l’adulte : évaluation des critères de sélection en consultation, à propos de 248 cas

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    INTRODUCTION: This work aims to evaluate selection criteria used during the cataract surgery scheduling visit, to choose whether or not there will be an anesthesiologist available during the surgery, depending upon the patient\u27s comorbidities. MATERIALS AND METHODS: Retrospective study performed in 2016 in Angers university medical center. Two groups were established on the cataract surgery scheduling visit, based on patients\u27 comorbidities and vital signs (blood pressure, heart rate). One group of patients were operated with topical anesthesia, with the anesthesia team, the other one only with blood pressure and heart rate monitoring, with, if needed, a written protocol of sedation or blood pressure control, which could be administrated by a circulating nurse. Those two groups were compared in terms of postoperative complications, intraoperative pain and postoperative visual acuity. RESULTS: 248 surgeries were performed on 185 individual patients, with 108 under stand-alone topical anesthesia, and 135 under anesthetist-monitored topical anesthesia. No significant difference was demonstrated between the two groups, in terms of complications, intraoperative pain or visual acuity outcomes. DISCUSSION: This study allows us to assess selection criteria used in our hospital to determine which patients can undergo cataract surgery under topical anesthesia without the anesthesia team. This procedure lowers organizational constraints while still insuring patient safety. Some patients still probably need an anesthesiologist present, such as those with an unstable disease or risk of agitation, in order to optimize the medications administered during surgery

    Low Band Gap Donor-Acceptor Conjugated Systems Based on 3-Alkoxy or 3-Pyrrolidino-4-cyanothiophene and Benzothiadiazole Units

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    3-Hexyloxy-4-cyanothiophene, 3-pyrrolidil-4-cyanothiophene, and 3,4-ethylenedioxythiophene (EDOT) units are used with benzothiadiazole as building blocks for the development of three new conjugated donor–acceptor–donor (DAD) derivatives. The DAD molecules have the central acceptor part, which is formed by combining electron-withdrawing cyano groups and the benzothiadiazole moiety, in common. Theoretical calculations and UV/Vis and electrochemical data reveal the key role of the end-capped donor to tune the electronic properties of the derivatives. A study of the electropolymerization process of the three derivatives shows the strong influence of the donor parts on both the reactivity of the precursors and the electronic properties of the resulting polymers. Derivatives end-capped with pyrrolidinocyano thiophene or EDOT units lead to films of polymers presenting low band gaps of around 0.9–1.4 eV. Upon oxidation, the two polymers present different behavior. In the presence of the pyrrolidinocyano thiophene moieties, oxidation leads to a blueshift of the absorption bands, whereas with EDOT units a classical redshift, giving high absorption in the near-IR region, is observed for the oxidized states

    Fluorine–fluorine type II versus πF–π stacking interactions in the supramolecular organizations of extended thiophene derivatives end capped by imino-perfluorophenyl units

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    The solid state arrangements of extended thiophene derivatives associating pentafluorophenyl units linked via azomethine bonds are analyzed in terms of intermolecular interactions involving hydrogen and halogen bonds and π−πF interactions. It is shown that in the presence of the shortest conjugated systems, the structure is driven by F⋯F type II contacts giving orthogonal disposition while the lengthening of the conjugated backbone favors parallel arrangements via π−πF interactions

    Hydrofoil Configurations for Sailing Superyachts: Hydrodynamics, Stability and Performance

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    Hydrofoil-assisted racing monohulls have undergone significant development phases in the past decade, yet very little scientific data has reached the public domain: an increasingly critical issue as the superyacht industry is now looking at the implementation of foils onto leisure vessels. Consequently, three contemporary configurations, namely a Dynamic Stability System, a Dali-Moustache and a Chistera have been towing tank tested to present the first complete characterisation of the hydrodynamic efficiency, quantification of the added dynamic stability and eventually the resulting impact on sailing performance. Furthermore, the considerations inherent to the design and installation of hydrofoils onto superyachts will be detailed. Building on extensive experimental work, this paper provides a comprehensive assessment of current design options with both technical and practical guidelines and recommendations to improve performance
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