Long-time relaxation in pilot-wave theory

We initiate the study of relaxation to quantum equilibrium over long timescales in pilot-wave theory. We simulate the time evolution of the coarse-grained H-function Hbar(t) for a two-dimensional harmonic oscillator. For a (periodic) wave function that is a superposition of the first 25 energy states we confirm an approximately exponential decay of Hbar over five periods. For a superposition of only the first four energy states we are able to calculate Hbar(t) over 50 periods. We find that, depending on the set of phases in the initial wave function, Hbar can decay to a large nonequilibrium residue exceeding 10% of its initial value or it can become indistinguishable from zero (the equilibrium value). We show that a large residue in Hbar is caused by a tendency for the trajectories to be confined to sub-regions of configuration space for some wave functions, and that this is less likely to occur for larger numbers of energy states (if the initial phases are chosen randomly). Possible cosmological implications are briefly discussed.Comment: 23 pages, 11 figures. Significant improvements in v2; new section on confinement of trajectories. Accepted by J. Phys. A: Math. Theo

The structural coverage of the human proteome before and after AlphaFold

The protein structure field is experiencing a revolution. From the increased throughput of techniques to determine experimental structures, to developments such as cryo-EM that allow us to find the structures of large protein complexes or, more recently, the development of artificial intelligence tools, such as AlphaFold, that can predict with high accuracy the folding of proteins for which the availability of homology templates is limited. Here we quantify the effect of the recently released AlphaFold database of protein structural models in our knowledge on human proteins. Our results indicate that our current baseline for structural coverage of 48%, considering experimentally-derived or template-based homology models, elevates up to 76% when including AlphaFold predictions. At the same time the fraction of dark proteome is reduced from 26% to just 10% when AlphaFold models are considered. Furthermore, although the coverage of disease-associated genes and mutations was near complete before AlphaFold release (69% of Clinvar pathogenic mutations and 88% of oncogenic mutations), AlphaFold models still provide an additional coverage of 3% to 13% of these critically important sets of biomedical genes and mutations. Finally, we show how the contribution of AlphaFold models to the structural coverage of non-human organisms, including important pathogenic bacteria, is significantly larger than that of the human proteome. Overall, our results show that the sequence-structure gap of human proteins has almost disappeared, an outstanding success of direct consequences for the knowledge on the human genome and the derived medical applications.E.P-P and V.R-S are supported by the La Caixa Junior Leader Fellowship LCF/BQ/PI18/11630003 from La Caixa Foundation (https://fundacionlacaixa.org/ca/home). E.P-P is also supported by a Ramon y Cajal fellowship from the Spanish Ministry of Science (RYC2019-026415-I). A.V. is supported by Institució Catalana de Recerca Avançada (ICREA - https://www.icrea.cat) The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer ReviewedPostprint (published version

O-Doped Nanographenes: A Pyrano/Pyrylium Route Towards Semiconducting Cationic Mixed-Valence Complexes

Herein we report an efficient synthesis to prepare O-doped nanographenes derived from the π-extension of pyrene. The derivatives are highly fluorescent and feature low oxidation potentials. Using electrooxidation, crystals of cationic mixed-valence (MV) complexes were grown in which the organic salts organize into face-to-face π-stacks, a favorable solid-state arrangement for organic electronics. Variable-temperature electron paramagnetic resonance (EPR) measurements and relaxation studies suggest a strong electron delocalization along the longitudinal axis of the columnar π-stacking architectures. Electric measurements of single crystals of the MV salts show a semiconducting behavior with a remarkably high conductivity at room temperature. These findings support the notion that π-extension of heteroatom-doped polycyclic aromatic hydrocarbons is an attractive approach to fabricate nanographenes with a broad spectrum of semiconducting properties and high charge mobilities

Challenges and improvement pathways to develop quasi-1D (Sb1-xBix)2Se3-based materials for optically tuneable photovoltaic applications. Towards chalcogenide narrow-bandgap devices

Quasi-1D chalcogenides have shown great promises in the development of emerging photovoltaic technologies. However, most quasi-1D semiconductors other than Sb2Se3 and Sb2S3 have been seldom investigated for energy generation applications. Indeed, cationic or anionic alloying strategies allow changing the bandgap of these materials, opening the door to the development of an extended range of chalcogenides with tuneable optical and electrical properties. In this work, Bi incorporation into the Sb2Se3 structure has been proved as an effective approach to modulate the bandgap between 0.1. In order to better understand the underlying mechanisms leading to the formation of (Sb1-xBix)2Se3, and thus design specific strategies to enhance its properties, thin films with different annealing time and temperature have been synthesized and characterized. Interestingly, it has been observed that Sb2Se3 and Bi2Se3 are formed first, with Bi melting at 300 ¿C and diffusing rapidly towards the surface of the film. At higher temperature, the binary compounds combine to form the solid solution, however as the dwell time increases, (Sb1-xBix)2Se3 decomposes again into Bi2Se3 and Sb. This study has shown that the material is essentially limited by compositional disorder and recombination via defects. Likewise, routes have been proposed to improve morphology and uniformity of the layer, achieving efficiencies higher than 1% for x > 0.2Postprint (published version

Voglie matte, merli maschi, peccati veniali. La questione sessuale nel cinema popolare italiano dal miracolo italiano all'avvento del porno

Special issue on Italian popular cinema and sexuality