Structural and electrical properties of annealed Ge2Sb2Te5 films grown on flexible polyimide

The morphological, structural, and electrical properties of as-grown and annealed Ge2Sb2Te5 (GST) layers, deposited by RF-sputtering on flexible polyimide, were studied by means of optical microscopy, atomic force microscopy, X-ray diffraction, Raman spectroscopy, and electrical characterization. The X-ray diffraction annealing experiments showed the structural transformation of GST layers from the as-grown amorphous state into their crystalline cubic and trigonal phases. The onset of crystallization of the GST films was inferred at about 140 degrees C. The vibrational properties of the crystalline GST layers were investigated via Raman spectroscopy with mode assignment in agreement with previous works on GST films grown on rigid substrates. The electrical characterization revealed a good homogeneity of the amorphous and crystalline trigonal GST with an electrical resistance contrast of 8 x 10(6)

Mechanisms of Activation of LRRC8 Volume Regulated Anion Channels.

Volume regulated anion channels (VRACs) are ubiquitously expressed in all vertebrate cells. Despite many years of research, the fundamental mechanisms underlying VRAC activation are not understood. The recent molecular identification of the LRRC8 genes underlying VRAC revealed that VRACs are formed by a hexameric assembly of members of the LRRC8 gene family. Knowing the genes underlying VRACs allowed the discovery of novel VRAC functions into cell volume regulation, and first structure function studies revealed important insight in channel activation mechanisms. The determination of cryo-EM structures of homomeric LRRC8A and LRRC8D complexes provide a framework for a rational approach to investigate biophysical mechanisms. We discuss several recent advances within the structural framework, and we critically review the literature on the main mechanisms proposed to be involved in VRAC activation, including low intracellular ionic strength, membrane unfolding, oxidation, phosphorylation and G-protein coupling

Interface formation during the growth of phase change material heterostructures based on Ge-Rich Ge-Sb-Te alloys

In this study, we present a full characterization of the electronic properties of phase change material (PCM) double-layered heterostructures deposited on silicon substrates. Thin films of amorphous Ge-rich Ge-Sb-Te (GGST) alloys were grown by physical vapor deposition on Sb2Te3 and on Ge2Sb2Te5 layers. The two heterostructures were characterized in situ by X-ray and ultraviolet photoemission spectroscopies (XPS and UPS) during the formation of the interface between the first and the second layer (top GGST film). The evolution of the composition across the heterostructure interface and information on interdiffusion were obtained. We found that, for both cases, the final composition of the GGST layer was close to Ge2SbTe2 (GST212), which is a thermodynamically favorable off-stoichiometry GeSbTe alloy in the Sb-GeTe pseudobinary of the ternary phase diagram. Density functional theory calculations allowed us to calculate the density of states for the valence band of the amorphous phase of GST212, which was in good agreement with the experimental valence bands measured in situ by UPS. The same heterostructures were characterized by X-ray diffraction as a function of the annealing temperature. Differences in the crystallization process are discussed on the basis of the photoemission results

Growth, electronic and electrical characterization of Ge-Rich Ge-Sb-Te alloy

In this study, we deposit a Ge-rich Ge-Sb-Te alloy by physical vapor deposition (PVD) in the amorphous phase on silicon substrates. We study in-situ, by X-ray and ultraviolet photoemission spectroscopies (XPS and UPS), the electronic properties and carefully ascertain the alloy composition to be GST 29 20 28. Subsequently, Raman spectroscopy is employed to corroborate the results from the photoemission study. X-ray diffraction is used upon annealing to study the crystallization of such an alloy and identify the effects of phase separation and segregation of crystalline Ge with the formation of grains along the [111] direction, as expected for such Ge-rich Ge-Sb-Te alloys. In addition, we report on the electrical characterization of single memory cells containing the Ge-rich Ge-Sb-Te alloy, including I-V characteristic curves, programming curves, and SET and RESET operation performance, as well as upon annealing temperature. A fair alignment of the electrical parameters with the current state-of-the-art of conventional (GeTe)n-(Sb2Te3)m alloys, deposited by PVD, is found, but with enhanced thermal stability, which allows for data retention up to 230 °C

Sul codice 8584 dell’Arsenal con Rime attribuite a Jacopo Corbinelli

Studio codicologico, paleografico e filologico del ms. Paris, Bibl. de l'Arsenal, 8584, contenente un corpus nutrito di rime attribuite a Jacopo Corbinelli. In appendice è offerta la trascrizione dell'intero codice

Toscane

Il Volume restituisce in forma di guida, itinerari dignificativi della Regione Toscana, con particolare atytenzione alla Natura, alla Storia e alla linguia, all'Arte e all'Architettura, alla letteratura e alla pittura. Il punto di vista multidisciplinare restituisce al volume il carattere di una 'Guida colta', aperta ad usi e interpretazioni multiple

3D reconstruction for preoperative planning of partial anomalous pulmonary venous return

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Supplemental material alignment -Supplemental material for Gain of function of sporadic/familial hemiplegic migraine-causing SCN1A mutations: Use of an optimized cDNA

<p>Supplemental material, Supplemental material alignment for Gain of function of sporadic/familial hemiplegic migraine-causing SCN1A mutations: Use of an optimized cDNA by Sara Bertelli, Raffaella Barbieri, Michael Pusch and Paola Gavazzo in Cephalalgia</p

Functional and Structural Characterization of ClC-1 and Nav1.4 Channels Resulting from CLCN1 and SCN4A Mutations Identified Alone and Coexisting in Myotonic Patients

Non-dystrophic myotonias have been linked to loss-of-function mutations in the ClC-1 chloride channel or gain-of-function mutations in the Nav1.4 sodium channel. Here, we describe a family with members diagnosed with Thomsen’s disease. One novel mutation (p.W322*) in CLCN1 and one undescribed mutation (p.R1463H) in SCN4A are segregating in this family. The CLCN1-p.W322* was also found in an unrelated family, in compound heterozygosity with the known CLCN1-p.G355R mutation. One reported mutation, SCN4A-p.T1313M, was found in a third family. Both CLCN1 mutations exhibited loss-of-function: CLCN1-p.W322* probably leads to a non-viable truncated protein; for CLCN1-p.G355R, we predict structural damage, triggering important steric clashes. The SCN4A-p.R1463H produced a positive shift in the steady-state inactivation increasing window currents and a faster recovery from inactivation. These gain-of-function effects are probably due to a disruption of interaction R1463-D1356, which destabilizes the voltage sensor domain (VSD) IV and increases the flexibility of the S4-S5 linker. Finally, modelling suggested that the p.T1313M induces a strong decrease in protein flexibility on the III-IV linker. This study demonstrates that CLCN1-p.W322* and SCN4A-p.R1463H mutations can act alone or in combination as inducers of myotonia. Their co-segregation highlights the necessity for carrying out deep genetic analysis to provide accurate genetic counseling and management of patients