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Background: Neuroinvasive properties of SARS-CoV-2 have allowed the hypothesis of several pathogenic mechanisms related to acute and chronic neurological sequelae. However, neuropathological correlates have been poorly systematically investigated, being retrieved from reports of single case or limited case series still. Methods: A PubMed search was carried out to review all publications on autopsy in subjects with “COronaVIrus Disease-19” (COVID-19). Among them, we focused on histological findings of the brain, which were compared with those from the authors’ autoptic studies performed in some COVID-19 patients. Results: Only seven studies reported histological evidence of brain pathology in patients deceased for COVID-19, including three with reverse transcription–quantitative polymerase chain reaction evidence of viral infection. All these studies, in line with our experience, showed vascular-related and infection-related secondary inflammatory tissue damage due to an abnormal immune response. It is still unclear, however, whether these findings are the effect of a direct viral pathology or rather reflect a non-specific consequence of cardiovascular and pulmonary disease on the brain. Conclusions: Notwithstanding the limited evidence available and the heterogeneity of the studies, we provide a preliminary description of the relationship between SARS-CoV-2 and brain sequelae. Systematic autoptic investigations are needed for accurate detection and adequate management of these patients.

In this paper, we study the performance of a 5G network working at mmW range for the uplink. We consider a single base station scenario equipped with a cylindrical array and a circular array (which can be seen as a single ring cylindrical array), isotropic and directive antenna elements are taken into account and we evaluate the trade-off between antennas per ring and number of rings with fixed number of total antennas. Users are modeled as a spatial Binomial point process in a hexagonal cell. As beamforming techniques, Conventional and Capon algorithms have been considered. As main KPI to evaluate system performance, we consider average achievable per-user rate with different system configurations, such as network loading. The key result of the trade-off investigation is that, when the radius of the cell is much larger than the height of the base station, the best performance occurs when the cylindrical array degenerates in a circular array both when users lay at ground level and with random heights.

Highly oriented luminescent films are produced by stretching a 30-μm-thick polyvinyl alcohol matrix doped with water-soluble polyrotaxanes and their unthreaded analogues. Photoluminescence experiments reveal that over 95% of the emitted light is polarized along the orientation direction. A hybrid organic-inorganic light-emitting diode is built to investigate the possibility of using these films as polarizing filters for solid-state lighting and display technology. © 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim.

We report on the optical properties of polystyrene opals infiltrated with solutions of ad hoc synthesized heteroaromatic quadrupolar dyes endowed with strong nonlinear optical properties (two-photon absorption). Transmittance spectroscopy of opals infiltrated with dye water solutions shows both a bathochromic shift and a reduced width of the photonic crystal stop band. Moreover, variable angle transmittance spectra highlight the high energy dispersion of the stop band upon increasing the incidence angle. Photoluminescence spectra recorded at different emission angles with respect to the normal of the sample for such infiltrated opals show that the emission spectrum is strongly modified at the stop band according to the opal dispersion properties. A careful comparison of the intensity and spectral properties of photoluminescence in opals possessing a properly tuned photonic stop band is reported and discussed. Two different effects are observed: when concentrated solutions are used, emitted light filtering due to the photonic stop band is observed. On the other hand, by properly reducing solution self-absorption, directional enhancement of emission in the high energy side of the stop band is observed. Physical mechanisms responsible for this phenomenon are discussed. © 2010 American Chemical Society.

Poly(9,9'-dioctyl fluorene) (F8) and poly(4,4'-diphenylene diphenylvinylene) (PDPV) are conjugated polymers with optical transitions that are nonresonant thanks to the particular structural features of PDPV that yield a very large Stokes' shift (similar to 1.14 eV) between absorption and emission spectra. We present steady-state and time-resolved photoluminescence (PL) experiments showing that F8:PDPV blends are "optically disconnected" systems for which the emission spectra and PL quantum yields are the linear combination of the contributions of the individual constituents with weights given by the respective absorption coefficients and concentration in the films. Single-layer light-emitting diodes incorporating F8:PDPV blends show white electroluminescence resulting from the simultaneous exploitation of the spectral features of both blend constituents (Commission Internationale de l'Eclairage, CIE, coordinates: x=0.27 and y=0.36, in the case of 8:2 F8:PDPV molar ratio). (C) 2010 American Institute of Physics. [doi: 10.1063/1.3387816]