Reactive molecular dynamics simulations of lithium-ion battery electrolyte degradation.

The development of reliable computational methods for novel battery materials has become essential due to the recently intensified research efforts on more sustainable energy storage materials. Here, we use a recently developed framework allowing to consistently incorporate quantum-mechanical activation barriers to classical molecular dynamics simulations to study the reductive solvent decomposition and formation of the solid electrolyte interphase for a graphite/carbonate electrolyte interface. We focus on deriving condensed-phase effective rates based on the elementary gas-phase reduction and decomposition energy barriers. After a short initial transient limited by the elementary barriers, we observe that the effective rate shows a transition to a kinetically slow regime influenced by the changing coordination environment and the ionic fluxes between the bulk electrolyte and the interface. We also discuss the impact of the decomposition on the ionic mobility. Thus, our work shows how elementary first-principles properties can be mechanistically leveraged to provide fundamental insights into electrochemical stability of battery electrolytes.

Optimisation de la prothèse complète supra-radiculaire mandibulaire par l'usage de l'attachement barre: rapport de cas / Optimization of the mandibular supra-radicular complete prosthesis by the use of the bar attachment: a case report

Introduction : L'équilibre d'une prothèse complète amovible mandibulaire est délicat vu la surface d'appui restreinte. L'objectif du travail était de décrire l'intérêt de la prothèse amovible supra-radiculaire retenue par l'attachement barre dans la gestion d'un édentement subtotal mandibulaire. Observation : Un patient consultait pour bénéficier d'une prothèse esthético-fonctionnelle. L'examen clinique montrait la présence d'un édentement total maxillaire et subtotal mandibulaire avec persistence des canines séparées d'une crête rectiligne. L'examen radiologique révélait un rapport couronne sur racine radiologique égal à 1. L'examen des moulages sur articulateur visualisait une hauteur occlusale utilisable suffisante. La décision prothétique était une prothèse complète maxillaire et une prothèse complète supra-radiculaire (PCSR) mandibulaire retenue par une barre. Le traitement prothétique commençait par une préparation Richmond des plateaux radiculaires. Après sculpture des chapes et fixation de la barre calcinable, la coulée était faite. Une empreinte anatomo-fonctionnelle de situation était réalisée pour confectionner l'infrastructure métallique. Suite à l'enregistrement de l'occlusion, le montage des dents était fait et validé. Le jour de la mise en bouche des conseils d'utilisation et de maintenance étaient prodigués au patient. Commentaires : La PCSR est avantageuse par le maintien du système proprioceptif desmodontal et d'un profil de crête favorable à l'appui. Les racines à conserver doivent valider certains critères pour être exploitables. La barre offre une rétention importante, mais son indication dépend du parallélisme radiculaire, de l'espace prothétique utilisable et de la forme de la crête édentée. Conclusion : Le recours aux attachements en PCSR est intéressant à condition d'établir un plan de traitement rigoureux et d'assurer la maintenance post-prothétique.

Introduction: The balance of a complete removable mandibular prosthesis is delicate given the limited support area. The objective of this work was to describe the benefit of the supra-radicular removable prosthesis retained by the bar attachment in the management of subtotal mandibular edentulism. Observation: A patient consulted to benefit from an aesthetical and functional prosthesis. The clinical examination showed the presence of total maxillary and subtotal mandibular edentulism with persistence of the canines separated by a straight ridge. The radiological examination revealed a crown by radiological root ratio equal to 1. Examination of the casts on the articulator visualized sufficient usable occlusal height. The prosthetic decision was a maxillary complete prosthesis and a mandibular complete supra-radicular prosthesis (CSRP) retained by a bar attachment. The prosthetic treatment began with a Richmond preparation of the root plates. After sculpting the copings and fixing the castable bar, the casting was done. An anatomo-functional impression was made to perform the metal infrastructure. Following the occlusion recording, the assembly of the teeth was done and validated. On the day of denture insertion, instructions about the use and the maintenance was provided to the patient. Comments: PCSR is advantageous by maintaining the periodontal proprioceptive system and a favorable ridge profile for prosthetic bearin. The roots to be kept must validate certain criteria to be usable. The bar offers significant retention, but its indication depends on the root parallelism, the usable prosthetic space and the shape of the edentulous ridge. Conclusion: The use of attachments in CSRP is interesting provided that a rigorous treatment plan is established and post-prosthetic maintenance is ensured.

Calibrated reservoir computers.

We observe the presence of infinitely fine-scaled alternations within the performance landscape of reservoir computers aimed for chaotic data forecasting. We investigate the emergence of the observed structures by means of variations of the transversal stability of the synchronization manifold relating the observational and internal dynamical states. Finally, we deduce a simple calibration method in order to attenuate the thus evidenced performance uncertainty.

Treatment of chickpea with Rhizobium isolates enhances the expression of phenylpropanoid defense-related genes in response to infection by Fusarium oxysporum f. sp. ciceris.

Differential expression of phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS) and isoflavone reductase (IFR) genes involved in phenylpropanoids metabolism was investigated using Northern blot analyses in chickpea seedlings bacterized with Rhizobium isolates (PchDMS and Pch43) and further challenged with Fusarium oxysporum f. sp. ciceris (Foc) race 0. Gene activation patterns in the moderately resistant accession INRAT87/1 were compared with those exhibited by the susceptible accession ILC482 at various time intervals after inoculation with Foc, to determine whether differences in levels or timing of transcript accumulation could be correlated with differences in the susceptibility of chickpea accessions to Foc. Gene activation was higher in the moderately resistant accession INRAT87/1 than in the susceptible ILC482. Pre-treatment of chickpea seedlings with Rhizobium isolates before inoculation with the pathogen enhanced the accumulation of the three genes' mRNA transcripts. In parallel, changes in the soluble phenolic pool produced through pathways involving these enzymes were analyzed in chickpea roots. A strong accumulation of these compounds was revealed at 72 hpi in both accessions. After that time, these high levels of phenolic compounds were maintained until the end of the experiment in the moderately resistant accession, while they have significantly declined in the susceptible accession. HPLC analyses revealed a very high accumulation of the constitutive isoflavones, formononetin and biochanin A and their glycoside conjugates in chickpea roots inoculated with Rhizobium isolates and/or challenged with Foc, as compared to the controls. Our results suggest that the increased accumulation of phenolic compounds, observed in chickpea seedlings inoculated with Foc, can be attributed to increased expression of genes in the phenylpropanoid pathway and that such gene expression is enhanced by pre-treatment with Rhizobium isolates.

Red/far-red and blue light-responsive regions of maize rbcS-m3 are active in bundle sheath and mesophyll cells, respectively.

Leaves of the C4 plant maize have two major types of photosynthetic cells: a ring of five large bundle sheath cells (BSC) surrounds each vascular bundle and smaller mesophyll cells (MC) lie between the cylinders of bundle sheath cells. The enzyme ribulose bisphosphate carboxylase/oxygenase is encoded by nuclear rbcS and chloroplast rbcL genes. It is not present in MC but is abundant in adjacent BSC of green leaves. As reported previously, the separate regions of rbcS-m3, which are required for stimulating transcription of the gene in BSC and for suppressing expression of reporter genes in MC, were identified by an in situ expression assay; expression was not suppressed in MC until after leaves of dark-grown seedlings had been illuminated for 24 h. Now we have found that transient expression of rbcS-m3 reporter genes is stimulated in BSC via a red/far-red reversible phytochrome photoperception and signal transduction system but that blue light is required for suppressing rbcS-m3 reporter gene expression in MC. Blue light is also required for the suppression system to develop in MC. Thus, the maize gene rbcS-m3 contains certain sequences that are responsive to a phytochrome photoperception and signal transduction system and other regions that respond to a UVA/blue light photoperception and signal transduction system. Various models of "coaction" of plant photoreceptors have been advanced; these observations show the basis for one type of coaction.

Transcriptional photoregulation of cell-type-preferred expression of maize rbcS-m3: 3' and 5' sequences are involved.

In the C4 plant maize, members of the rbcS gene family, encoding the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase, are not expressed in mesophyll cells (MC) but are expressed strongly in the adjacent bundle sheath cells (BSC). Expression of genes in an in situ transient expression assay indicates that the photostimulated expression seen in BSC during the first 24 h that leaves of dark-grown seedlings are illuminated requires rbcS-m3 sequences lying between -211 bp and +434 bp of the transcription start site. Photoregulated partial suppression of rbcS-m3 expression in MC, on the other hand, requires gene sequences that lie between -907 bp and -445 bp together with sequences that lie between +720 and +957 bp within the 3' transcribed region of the gene. Suppression in MC occurs during the second 24-h period that dark-grown seedlings have been illuminated, but not during the first 24 h. The 3' +720- to +957-bp region is also effective in lowering MC expression when it is relocated to a position > 2 kbp upstream of the transcription start site. Thus, suppression of rbcS-m3 expression in MC has, at the least, a substantial transcriptional component. As reported earlier, a converse pattern of suppression in BSC and stimulation of expression in MC is seen in the control of cab-m1 in maize leaves.