Experimental and theoretical studies of tetramethoxy-p-benzoquinone: infrared spectra, structural and lithium insertion properties

International audienceIn the search for low-polluting electrode materials for batteries, the use of redox-active organic compounds represents a promising alternative to conventional metal-based systems. In this article we report a combined experimental and theoretical study of tetramethoxy-p-benzoquinone (TMQ). In carbonate-based electrolytes, electrochemical behaviour of this compound is characterized by a reversible insertion process located at approximately 2.85 V vs. Li+/Li0. This relatively high potential reactivity, coupled with our effort to develop computational methodologies in the field of organic electrode materials, prompted us to complement these experimental data with theoretical studies performed using density functional theory (DFT). Single crystals of TMQ were synthesized and thoroughly characterized showing that this quinonic species crystallised in the P21/n space group. The experimental crystal structure of TMQ was then used to assess various DFT methods. The structural features and vibrational spectra were thus predicted by using as a whole five common density functionals (PBE, LDA, revPBE, PBEsol, B3PW91) with and without a semi-empirical correction to account for the van der Waals interactions using either Grimme's (DFT-D2) or Tkatchenko-Scheffler (TS) scheme. The most reliable combination of the DFT functional and the explicit dispersion correction was chosen to study the Li-intercalated molecular crystal (LiTMQ) with the view of indentifying Li insertion sites. A very close agreement with the experiment was found for the average voltage by using the most stable relaxed hypothetical LiTMQ structure. Additionally, a comparison of vibrational spectra gained either for TMQ molecule and its dimer in gas phase or through periodic calculation was undertaken with respect to the experimentally measured infrared spectra. The topological features of the bonds were also investigated in conjunction with estimates of net atomic charges to gain insight into the effect of chemical bonding and intermolecular interaction on Li intercalation. Finally, π-electron delocalization of both quinone and alkali salts of p-semiquinone were determined using the Harmonic Oscillator model of Aromaticity (HOMA) or aromatic fluctuation index (FLU) calculations

KIAA1109 Variants Are Associated with a Severe Disorder of Brain Development and Arthrogryposis.

Whole-exome and targeted sequencing of 13 individuals from 10 unrelated families with overlapping clinical manifestations identified loss-of-function and missense variants in KIAA1109 allowing delineation of an autosomal-recessive multi-system syndrome, which we suggest to name Alkuraya-Kučinskas syndrome (MIM 617822). Shared phenotypic features representing the cardinal characteristics of this syndrome combine brain atrophy with clubfoot and arthrogryposis. Affected individuals present with cerebral parenchymal underdevelopment, ranging from major cerebral parenchymal thinning with lissencephalic aspect to moderate parenchymal rarefaction, severe to mild ventriculomegaly, cerebellar hypoplasia with brainstem dysgenesis, and cardiac and ophthalmologic anomalies, such as microphthalmia and cataract. Severe loss-of-function cases were incompatible with life, whereas those individuals with milder missense variants presented with severe global developmental delay, syndactyly of 2nd and 3rd toes, and severe muscle hypotonia resulting in incapacity to stand without support. Consistent with a causative role for KIAA1109 loss-of-function/hypomorphic variants in this syndrome, knockdowns of the zebrafish orthologous gene resulted in embryos with hydrocephaly and abnormally curved notochords and overall body shape, whereas published knockouts of the fruit fly and mouse orthologous genes resulted in lethality or severe neurological defects reminiscent of the probands' features.This article is freely available via Open Access. Click on the Additional Link above to access the full-text via the publisher's site

Le potentiel énergétique d’une nouvelle commune: cas de la commune d’Anniviers en Valais

En analysant la situation du Val d’Anniviers, le présent travail de bachelor a pour objectif d’identifier le potentiel énergétique d’une nouvelle commune. Pour y parvenir, l’analyse se base sur l’outil pour les communes du programme SuisseÉnergie à savoir le label « Cité de l’énergie ». Le but de cette démarche est de repenser la politique énergétique communale en l’analysant selon les six domaines définis par le label à savoir : l’aménagement du territoire, les bâtiments communaux, l’approvisionnement - dépollution, la mobilité, l’organisation interne et la communication. L’état des lieux montre que la commune remplit une grande partie des critères exigés. Le domaine de l’approvisionnement – dépollution est le plus avancé, notamment grâce au travail titanesque réalisé dans la gestion des déchets et des eaux usées ainsi qu’à la part du capital-actions détenues dans la société Gougra SA lui permettant d’être autonome en électricité. Le programme de rénovation des bâtiments communaux et les importants moyens investit pour développer une mobilité douce au sein de la vallée répondent aux exigences du label, car ils prônent une consommation responsable tout en développant les nouvelles énergies renouvelables. L’état des lieux fait également ressortir plusieurs lacunes, mais la commune peut y remédier en instaurant certaines améliorations. Pour ce faire, elle doit définir dans un document officiel la politique énergétique communale. Celle-ci doit contenir des objectifs chiffrés sur la réduction de la consommation en énergie et des émissions de gaz à effet de serre ainsi qu’un plan d’action précis pour y parvenir. Par ailleurs, la commune doit améliorer son plan de communication pour sensibiliser davantage la population car la problématique énergétique est une affaire de tous. L’analyse montre que la nouvelle commune d’Anniviers répond aux critères du label « Cité de l’énergie ». Sans la fusion il aurait été extrêmement difficile, voire impossible d’obtenir ce même résultat, chaque commune voulant privilégier un secteur plutôt qu’un autre. Les synergies créées lors de la fusion et le résultat favorable de l’analyse prouvent qu’il existe un potentiel énergétique dans une nouvelle commune

Limiteur de courant de court-circuit supraconducteur résistif : prémices d'un modèle circuit multi-échelle

National audienceWith the increase of electricity demand, the level of short circuit current can exceed the breaking capacity of the existing equipment. To avoid expensive replacement of circuit breakers, while enjoying the benefits of increased meshed network stability and availability of energy, superconducting fault current limiter (SFCL) can be a good way to solve the problem. This device can limit the first peak of the short-circuit currents in some ms (about 2 ms). In view of the number of prototypes installed and tested in recent years, this technology could integrate in existing power systems in the short term. To facilitate the SFCL installation, it is necessary to develop, in network simulation tools, precise models that allow to analyses its impact on existing electrical power system. Thus, we propose, in this paper, an electro-thermal multi-scale model of a resistive SFCL based exclusively on electrical circuit.La demande en énergie électrique étant en constante progression, les puissances installées, la complexité et le maillage des réseaux ne cessent de croitre, ce qui n’est pas sans impact sur les courants de court-circuit qui peuvent, dans certains cas, dépasser le pouvoir de coupure des appareillages mis en place. Pour éviter un coûteux remplacement des disjoncteurs, tout en bénéficiant des avantages d’un maillage accru du réseau sur la stabilité et la disponibilité de l’énergie, l’installation de limiteur de courant supraconducteur (LCS) permet de limiter l’amplitude des courants de court-circuit et ce, dès le premier pic. À la vue du nombre de prototypes installés et testés ces dernières années, cette technologie pourrait bien, à court terme, intégrer les réseaux. Afin de faciliter l’installation des LCS, il est nécessaire de développer, dans les outils de simulation de réseau, des modèles au comportement précis qui permettent d’étudier au préalable l’impact de ce nouvel appareillage. Ainsi, nous proposons une base de modèle électrothermique multi-échelle, sous forme de circuit électrique, d’un LCS de type résistif

The low/room-temperature forms of the lithiated salt of 3,6-dihydroxy-2,5-dimethoxy-p-benzoquinone: a combined experimental and dispersion-corrected density functional study

International audienceFollowing our first experimental and computational study of the room temperature (RT) form of the tetrahydrated 3,6-dihydroxy-2,5-dimethoxy-p-benzoquinone dilithium salt (Li2DHDMQ?4H2O), we have researched the occurrence of hydrogen ordering in a new polymorph at lower temperature. The study of polymorphism for the Li2DHDMQ?4H2O phase employs both experimental (single crystal X-ray diffraction) and theoretical approaches. While clues for disorder over one bridging water molecule were observed at RT (b form), a fully ordered model within a supercell has been evidenced at 100 K (a form) and is discussed in conjunction with the features characterizing the first polymorphic form reported previously. Density functional theory (DFT) calculations augmented with an empirical dispersion correction (DFT-D) were applied for the prediction of the structural and chemical bonding properties of the a and b polymorphs of Li2DHDMQ?4H2O. The relative stability of the two polymorphic systems is evidenced. An insight into the interplay of hydrogen bonding, electrostatic and van der Waals (vdW) interactions in affecting the properties of the two polymorphs is gained. This study also shows how information from DFT-D calculations can be used to augment the information from the experimental crystal diffraction data and can so play an active role in crystal structure determination, especially by increasing the reliability and accuracy of H-positioning. These more accurate hydrogen coordinates allowed for a quantification of H-bonding strength through a topological analysis of the electron density (atoms-in-molecules theory)

High-Potential Reversible Li Deintercalation in a Substituted Tetrahydroxy-p-benzoquinone Dilithium Salt: An Experimental and Theoretical Study

International audiencePromoting the emergence of efficient organic Li-ion batteries requires notably air-stable lithiated organic structures able to reversibly deintercalate Li at high enough potential values. To date, most of cathode materials reported in the literature are typically synthesized in their fully oxidized form, which restricts the operating potential of such materials and supposes the use of an anode material in its lithiated state. Reduced forms of quinonic structures could represent examples of lithiated organic-based cathode able to deintercalate Li+ at potentials higher than 3 V thanks to substituent effects. Having previously recognized the unique electrochemical properties of the C6O6-type ring, we have designed then elaborated through a simple three-step method the lithiated salt of 3,6-dihydroxy-2,5-dimethoxy-p-benzoquinone, a new redox amphoteric system deriving from the tetralithium salt of tetrahydroxy-p-benzoquinone. Electrochemical investigations have particularly revealed that such an air-stable salt may reversibly deintercalate one Li+ upon charging with a practical capacity of about 100 mAh g1 at near 3 V with, however, a polarization effect. Better capacity retention was successfully obtained by simply adding an adsorbing additive. A tetrahydrated form of the studied salt was also characterized from XRD and first-principles calculations. Various levels of theory were probed including DFT with classical functionals (LDA, GGA, PBEsol, revPBE) and models for dispersion corrections to DFT. One of the modified dispersion-corrected DFT schemes, related to a rescaling of both van der Waals radii and s6 parameter, provides significant improvements for the description of this crystal kind over other treatments. We then applied this optimized approach to the screening of hypothetical frameworks for the delithiated phases and to the search for the anhydrous structure

Prospective Multicenter Validation of the Detection of ALK Rearrangements of Circulating Tumor Cells for Noninvasive Longitudinal Management of Patients With Advanced NSCLC

International audienceIntroduction: Patients with advanced-stage NSCLC whose tumors harbor an ALK gene rearrangement benefit from treatment with multiple ALK inhibitors (ALKi). Approximately 30% of tumor biopsy samples contain insufficient tissue for successful ALK molecular characterization. This study evaluated the added value of analyzing circulating tumor cells (CTCs) as a surrogate to ALK tissue analysis and as a function of the response to ALKi.Methods: We conducted a multicenter, prospective observational study (NCT02372448) of 203 patients with stage IIIB/IV NSCLC across nine French centers, of whom 81 were ALK positive (immunohistochemistry or fluorescence in situ hybridization [FISH]) and 122 ALK negative on paraffin-embedded tissue specimens. Blood samples were collected at baseline and at 6 and 12 weeks after ALKi initiation or at disease progression. ALK gene rearrangement was evaluated with CTCs using immunocytochemistry and FISH analysis after enrichment using a filtration method.Results: At baseline, there was a high concordance between the detection of an ALK rearrangement in the tumor tissue and in CTCs as determined by immunocytochemistry (sensitivity, 94.4%; specificity 89.4%). The performance was lower for the FISH analysis (sensitivity, 35.6%; specificity, 56.9%). No significant association between the baseline levels or the dynamic change of CTCs and overall survival (hazard ratio = 0.59, 95% confidence interval: 0.24-1.5, p = 0.244) or progression-free survival (hazard ratio = 0.84, 95% confidence interval: 0.44-1.6, p = 0.591) was observed in the patients with ALK-positive NSCLC.Conclusions: CTCs can be used as a complementary tool to a tissue biopsy for the detection of ALK rearrangements. Longitudinal analyses of CTCs revealed promise for real-time patient monitoring and improved delivery of molecularly guided therapy in this population

Efficacy and Safety of Rovalpituzumab Tesirine Compared With Topotecan as Second-Line Therapy in DLL3-High SCLC: Results From the Phase 3 TAHOE Study

International audienc