Correction: The role of ion solvation in lithium mediated nitrogen reduction.

[This corrects the article DOI: 10.1039/D2TA07686A.].

The role of ion solvation in lithium mediated nitrogen reduction.

Since its verification in 2019, there have been numerous high-profile papers reporting improved efficiency of lithium-mediated electrochemical nitrogen reduction to make ammonia. However, the literature lacks any coherent investigation systematically linking bulk electrolyte properties to electrochemical performance and Solid Electrolyte Interphase (SEI) properties. In this study, we discover that the salt concentration has a remarkable effect on electrolyte stability: at concentrations of 0.6 M LiClO4 and above the electrode potential is stable for at least 12 hours at an applied current density of -2 mA cm-2 at ambient temperature and pressure. Conversely, at the lower concentrations explored in prior studies, the potential required to maintain a given N2 reduction current increased by 8 V within a period of 1 hour under the same conditions. The behaviour is linked more coordination of the salt anion and cation with increasing salt concentration in the electrolyte observed via Raman spectroscopy. Time of flight secondary ion mass spectrometry and X-ray photoelectron spectroscopy reveal a more inorganic, and therefore more stable, SEI layer is formed with increasing salt concentration. A drop in faradaic efficiency for nitrogen reduction is seen at concentrations higher than 0.6 M LiClO4, which is attributed to a combination of a decrease in nitrogen solubility and diffusivity as well as increased SEI conductivity as measured by electrochemical impedance spectroscopy.

The origin of overpotential in lithium-mediated nitrogen reduction.

The verification of the lithium-mediated nitrogen reduction system in 2019 has led to an explosion in the literature focussing on improving the metrics of faradaic efficiency, stability, and activity. However, while the literature acknowledges the vast intrinsic overpotential for nitrogen reduction due to the reliance on in situ lithium plating, it has thus far been difficult to accurately quantify this overpotential and effectively analyse further voltage losses. In this work, we present a simple method for determining the Reversible Hydrogen Electrode (RHE) potential in the lithium-mediated nitrogen reduction system. This method allows for an investigation of the Nernst equation and reveals sources of potential losses. These are namely the solvation of the lithium ion in the electrolyte and resistive losses due to the formation of the solid electrolyte interphase. The minimum observed overpotential was achieved in a 0.6 M LiClO4, 0.5 vol% ethanol in tetrahydrofuran electrolyte. This was -3.59 ± 0.07 V vs. RHE, with a measured faradaic efficiency of 6.5 ± 0.2%. Our method allows for easy comparison between the lithium-mediated system and other nitrogen reduction paradigms, including biological and homogeneous mechanisms.

Hypothalamic-pituitary Langerhans cell histiocytosis: a diagnostic challenge.

Four cases of hypothalamic-pituitary Langerhans cell histiocytosis (LCH) are reported, highlighting the expanding spectrum of clinical and magnetic resonance imaging (MRI) features in adults. The diagnostic challenge of hypothalamic-pituitary LCH is emphasized in cases revealed as supra-sellar tumors with panhypopituitarism or as isolated central diabetes insipidus. Diagnosis is confirmed by histological examination showing infiltration with CD1a positive histiocytes. General guidelines for diagnosis procedure are drawn out, including the neurosurgical biopsy in particular cases.

[Fracture of the sacrum caused by bone insufficiency in a pregnant woman]. / Fracture du sacrum par insuffisance osseuse chez une femme enceinte.

Sacral insufficiency fractures are not rare. They are well known in female patients over age 50 with osteopenia. One case occurring in a young pregnant woman is described. We did not find another case in the literature.

[Disk herniation with posterior ring apophysis fracture in young adults]. / Hernie discale avec fracture du listel marginal postérieur chez l'adulte jeune.

Fracture of the posterior ring apophysis in association with a herniated disk is unusual in adult patients. It has to be considered as a posterior pre-marginal disk hernia, a variant of marginal cartilaginous nodes. This report concerns one young adult with lumbar and sciatic pain presenting a posterior marginal node with fracture of the posterior ring apophysis and conventional posterior disk herniation. Computed tomographic findings and magnetic resonance images are described.

[MRI and chronic osteoarticular infections. Contribution of inversion-recuperation sequence with fat signal cancellation in the follow-up of chronic osteitis under medical treatment. Apropos of 14 cases]. / IRM et infections ostéo-articulaires chroniques. Apport de la séquence inversion-récupération avec annulation des graisses dans le suivi des ostéites chroniques sous traitement médical. A propos de 14 cas.

MR Imaging was performed with T1 weighted, Rho T2* (Grass) and S.T.I.R. sequences on medically treated chronic osteomyelitis patients. MR Imaging is definitely the best tool available in thorough evaluation of the extent of lesions. It allows the evolution or remission of focal inflammatory lesions to be traced for follow up. Bone sequestra needing surgery can be identified and soft tissue abcesses differentiated from cellulitis. In future, MR Imaging could replace tomography and fistulography, while scintigraphy would be more useful in cases of recent acute infections and their differential diagnoses.

[Double contrast radiological study of the small intestine with duodeno-jejunal intubation. The technique used at the Nice University Hospital Centr with a report of first results (author's transl)]. / L'étude radiologique en double contraste de l'intestin grêle sous intubation duodéno-jéjunale. Notre technique au C.H.U. de Nice et premiers résultats

The authors have carried out 80 radiological studies by duodeno-jejunal intubation using a tube which they themselves perfected. The technique is simple and easily reveals organic lesions. Barium studies of the small intestine via duodeno-jejunal intubation further makes it possible to assess its tone and peristalsis. The authors feel this technique to be the most suitable for this technique purpose.

[Asymmetry of the cerebral hemispheres in man: a bridge binding the 1st and the 2d temporal gyri, superior face of the 2d temporal gyrus, and fusiform gyrus]. / A propos des asymétries des hémisphères cérébraux chez l'homme: pont reliant la première et la deuxième circonvolution temporale face supérieure de la deuxième circonvolution temporale, gyrus fusiforme

The autors study 76 human brains, 36 of which are dissected. They observe a "T1 T2 bridge" over the first temporal and second temporal gyri more often on the left side than on the right. They find the maximal width of the superior face of the second temporal gyrus predominant on the right side in 70% of cases, on the left side in 15% and equivalent on both sides in 15%. The fusiform gyrus is found wider on the left side in 53% of cases, on the right in 22% and equivalent on both sides in 25%.