Demonstration of Nanosecond Operation in Stochastic Magnetic Tunnel Junctions.

Magnetic tunnel junctions operating in the superparamagnetic regime are promising devices in the field of probabilistic computing, which is suitable for applications like high-dimensional optimization or sampling problems. Further, random number generation is of interest in the field of cryptography. For such applications, a device's uncorrelated fluctuation time-scale can determine the effective system speed. It has been theoretically proposed that a magnetic tunnel junction designed to have only easy-plane anisotropy provides fluctuation rates determined by its easy-plane anisotropy field and can perform on a nanosecond or faster time-scale as measured by its magnetoresistance's autocorrelation in time. Here, we provide experimental evidence of nanosecond scale fluctuations in a circular-shaped easy-plane magnetic tunnel junction, consistent with finite-temperature coupled macrospin simulation results and prior theoretical expectations. We further assess the degree of stochasticity of such a signal.

[New developments in headache management in 2022]. / Nouveautés dans la prise en charge des céphalées.

Headaches are one of the most common causes of consultation in primary care. Due to their polymorphic character and sometimes severe etiologies, it is very important to properly classify these symptoms and to look for possible associated signs of severity. It is with this objective that the international classification of headache delivered its 3rd version in 2018 with the ICHD-3. In addition, revised and validated severity criteria were also published in 2018 under the name SNNOOP10. At the same time, the concept of green flags which could allow to diagnose a primary headache without further investigations has emerged. In terms of treatment, the development of CGRP neuropeptide antagonists has allowed a major advance in the treatment of the severe forms of migraine. Finally, integrative medicine is taking on a central role.

Les céphalées sont l'un des motifs de consultation les plus courants en médecine de premier recours. En raison de leur caractère polymorphe et des étiologies potentiellement graves, il est essentiel de bien les classifier et de rechercher les signes de sévérité associés. C'est dans cet objectif que la classification internationale des céphalées a livré sa troisième version en 2018 (ICHD-3). Des critères de sévérité révisés et validés ont également été publiés en 2018 sous le nom de SNNOOP10. En parallèle, le concept de drapeaux verts, qui permettrait de retenir un diagnostic de céphalées primaires sans autres examens, a émergé. En termes de traitement, le développement d'antagonistes du neuropeptide CGRP (Calcitonin Gene-Related Peptide) a permis une avancée majeure dans le traitement des formes de migraine sévères. La médecine intégrative y prend par ailleurs une place centrale.

Detection of charge storage on molecular thin films of tris(8-hydroxyquinoline) aluminum (Alq3) by Kelvin force microscopy: a candidate system for high storage capacity memory cells.

Retention and diffusion of charge in tris(8-hydroxyquinoline) aluminum (Alq(3)) molecular thin films are investigated by injecting electrons and holes via a biased conductive atomic force microscopy tip into the Alq(3) films. After the charge injection, Kelvin force microscopy measurements reveal minimal changes with time in the spatial extent of the trapped charge domains within Alq(3) films, even for high hole and electron densities of >10(12) cm(-2). We show that this finding is consistent with the very low mobility of charge carriers in Alq(3) thin films (<10(-7) cm(2)/(Vs)) and that it can benefit from the use of Alq(3) films as nanosegmented floating gates in flash memory cells. Memory capacitors using Alq(3) molecules as the floating gate are fabricated and measured, showing durability over more than 10(4) program/erase cycles and the hysteresis window of up to 7.8 V, corresponding to stored charge densities as high as 5.4 × 10(13) cm(-2). These results demonstrate the potential for use of molecular films in high storage capacity nonvolatile memory cells.