20 research outputs found
Transfert de la pédiatrie à l'adulte de patients atteints de mucoviscidose : le vécu des patients et des équipes au CHU de Nice
Introduction : Depuis des décennies, le pronostic de la mucoviscidose s'est amélioré. Actuellement, près de 50% des patients ont plus de 18 ans, ce qui conduit à la nécessité de transférer ces jeunes adultes dans des centres de soins adaptés à leur âge. Par cette étude, nous avons analysé les modalités de transfert de patients de la pédiatrie à l'adulte au centre adulte du CRCM de Nice. Matériels et méthodes : De septembre 2012 à mars 2013, 15 patients, 1 équipe de pneumologie adulte et 5 équipes pédiatriques ont répondu à un questionnaire évaluant leur vécu du transfert, ses modalités et les obstacles rencontrés. Résultats : L'âge moyen au moment du transfert était de 20,1 ans±2,2 ans. Le vécu du transfert était meilleur pour les patients que pour les équipes. Le critère principal de transfert était l'âge (80%). La période de transition était courte ; elle a duré moins de 3 mois pour plus de la moitié des patients. Seuls 2 patients ont bénéficié d'une consultation pré-transfert avec le pneumologue adulte en pédiatrie. Le manque d'explications concernant le transfert risque d'entraîner un mauvais vécu de ce transfert par le patient. La transition des soins ainsi que les obstacles sont ressentis différemment entre les patients et les soignants. Discussion : La transition des soins fait partie d'un processus global du développement vers l'âge adulte. Le protocole de transfert doit être souple et adapté à chaque patient. Le transfert doit être anticipé et progressif, expliqué de façon claire au patient et doit amener à son autonomisation. Les consultations pré-transfert visant à rencontrer l'équipe adulte sont importantes. Le moment du transfert doit certes prendre en compte l'âge civil du patient mais aussi son état psycho-social et médical. La collaboration des équipes est essentielle. Conclusion : Des améliorations doivent être apportées au protocole de transition actuel afin que le transfert se passe au mieux pour le patient, sa famille et les acteurs de soins
Redox Chemistry and the Role of Trapped Molecular O<sub>2</sub>in Li-Rich Disordered Rocksalt Oxyfluoride Cathodes
In the search for high energy density cathodes for next-generation lithium-ion batteries, the disordered rocksalt oxyfluorides are receiving significant attention due to their high capacity and lower voltage hysteresis compared with ordered Li-rich layered compounds. However, a deep understanding of these phenomena and their redox chemistry remains incomplete. Using the archetypal oxyfluoride, Li2MnO2F, we show that the oxygen redox process in such materials involves the formation of molecular O2 trapped in the bulk structure of the charged cathode, which is reduced on discharge. The molecular O2 is trapped rigidly within vacancy clusters and exhibits minimal mobility unlike free gaseous O2, making it more characteristic of a solid-like environment. The Mn redox process occurs between octahedral Mn3+ and Mn4+ with no evidence of tetrahedral Mn5+ or Mn7+. We furthermore derive the relationship between local coordination environment and redox potential; this gives rise to the observed overlap in Mn and O redox couples and reveals that the onset potential of oxide ion oxidation is determined by the degree of ionicity around oxygen, which extends models based on linear Li-O-Li configurations. This study advances our fundamental understanding of redox mechanisms in disordered rocksalt oxyfluorides, highlighting their promise as high capacity cathodes
Redox Chemistry and the Role of Trapped Molecular O<sub>2</sub>in Li-Rich Disordered Rocksalt Oxyfluoride Cathodes
In the search for high energy density cathodes for next-generation lithium-ion batteries, the disordered rocksalt oxyfluorides are receiving significant attention due to their high capacity and lower voltage hysteresis compared with ordered Li-rich layered compounds. However, a deep understanding of these phenomena and their redox chemistry remains incomplete. Using the archetypal oxyfluoride, Li2MnO2F, we show that the oxygen redox process in such materials involves the formation of molecular O2 trapped in the bulk structure of the charged cathode, which is reduced on discharge. The molecular O2 is trapped rigidly within vacancy clusters and exhibits minimal mobility unlike free gaseous O2, making it more characteristic of a solid-like environment. The Mn redox process occurs between octahedral Mn3+ and Mn4+ with no evidence of tetrahedral Mn5+ or Mn7+. We furthermore derive the relationship between local coordination environment and redox potential; this gives rise to the observed overlap in Mn and O redox couples and reveals that the onset potential of oxide ion oxidation is determined by the degree of ionicity around oxygen, which extends models based on linear Li-O-Li configurations. This study advances our fundamental understanding of redox mechanisms in disordered rocksalt oxyfluorides, highlighting their promise as high capacity cathodes.</p
Phosphate Ion Functionalization of Perovskite Surfaces for Enhanced Oxygen Evolution Reaction
Recent findings revealed that surface oxygen can participate in the oxygen evolution reaction (OER) for the most active catalysts, which eventually triggers a new mechanism for which the deprotonation of surface intermediates limits the OER activity. We propose in this work a “dual strategy” in which tuning the electronic properties of the oxide, such as La1–xSrxCoO3??, can be dissociated from the use of surface functionalization with phosphate ion groups (Pi) that enhances the interfacial proton transfer. Results show that the Pi functionalized La0.5Sr0.5CoO3?? gives rise to a significant enhancement of the OER activity when compared to La0.5Sr0.5CoO3?? and LaCoO3. We further demonstrate that the Pi surface functionalization selectivity enhances the activity when the OER kinetics is limited by the proton transfer. Finally, this work suggests that tuning the catalytic activity by such a “dual approach” may be a new and largely unexplored avenue for the design of novel high-performance catalysts
Transcranial electrical and magnetic stimulation (tES and TMS) for addiction medicine: A consensus paper on the present state of the science and the road ahead
There is growing interest in non-invasive brain stimulation (NIBS) as a novel treatment option for substance-use disorders (SUDs). Recent momentum stems from a foundation of preclinical neuroscience demonstrating links between neural circuits and drug consuming behavior, as well as recent FDA-approval of NIBS treatments for mental health disorders that share overlapping pathology with SUDs. As with any emerging field, enthusiasm must be tempered by reason; lessons learned from the past should be prudently applied to future therapies. Here, an international ensemble of experts provides an overview of the state of transcranial-electrical (tES) and transcranial-magnetic (TMS) stimulation applied in SUDs. This consensus paper provides a systematic literature review on published data – emphasizing the heterogeneity of methods and outcome measures while suggesting strategies to help bridge knowledge gaps. The goal of this effort is to provide the community with guidelines for best practices in tES/TMS SUD research. We hope this will accelerate the speed at which the community translates basic neuroscience into advanced neuromodulation tools for clinical practice in addiction medicine
Major element composition of the atmospheric mineral dust extracted from the Talos Dome ice core sections
Revealing pH-Dependent Activities and Surface Instabilities for Ni-Based Electrocatalysts during the Oxygen Evolution Reaction
International audienceMultiple electrochemical processes are involved at the catalyst/electrolyte interface during the oxygen evolution reaction (OER). With the purpose of elucidating the complexity of surface dynamics upon OER, we systematically studied two Ni-based crystalline oxides (LaNiO3−δ and La2Li0.5Ni0.5O4) and compared them with the state-of-the-art Ni–Fe (oxy)hydroxide amorphous catalyst. Electrochemical measurements such as rotating ring disk electrode (RRDE) and electrochemical quartz microbalance microscopy (EQCM) coupled with a series of physical characterizations including transmission electron microscopy (TEM) and X-ray absorption spectroscopy (XAS) were conducted to unravel the exact pH effect on both the OER activity and the catalyst stability. We demonstrate that for Ni-based crystalline catalysts the rate for surface degradation depends on the pH and is greater than the rate for surface reconstruction. This behavior is unlike that for the amorphous Ni oxyhydroxide catalyst, which is found to be more stable and pH-independent
Major element composition of dust in potential source areas from Antarctica (Victoria Land), Australia and South America
Holocene and MIS2 atmospheric mineral dust concentration and composition from the Talos Dome ice core and from potential source areas
The present data concerns:
-Atmospheric dust concentration from the Antarctic ice core Talos Dome during the time interval between 700 and 25,000 years before present (AICC2012 chronology).
-Dust Potential Source Areas Composition: the major element composition of potential dust source areas from Antarctica (Victoria Land), Australia and South America.
-The major element composition of the atmospheric mineral dust extracted from the Talos Dome ice core sections. The age of the samples ranges between 1.9 Kyr BP and 32.9 Kyr BP (AICC2012 chronology)