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The introduction in the past few years of advanced optical coherence tomography (OCT) techniques has greatly increased our understanding of the choroid, which is the most important vascular layer of the eye. Our study aimed to assess choroidal thickness by using swept-source OCT (SS-OCT) in essential hypertensive patients (EHs) with and without early-stage chronic kidney disease (CKD). We enrolled 100 EHs, of whom 65 were without kidney damage, and 35 had stage 1-3 CKD. In all of the participants, SS-OCT and a routine biochemical workup were performed. Glomerular filtration rate (GFR) was estimated by the CKD Epidemiology Collaboration equation (eGFR). CKD was defined in agreement with the Kidney Disease Outcomes Quality Initiative Kidney Disease: Improving Global Outcomes 2002 guidelines. OCT measurements were performed according to the Early Treatment Diabetic Retinopathy Study (ETDRS) protocol, which divides the macula into nine subfields. The circular grid consists of three concentric rings. EHs with CKD showed thinner choroidal thicknesses than those without it (all p < 0.05), even after adjustment for potential confounding factors. Overall choroidal thickness correlated significantly and directly with eGFR (r = 0.36) and negatively with urinary albumin excretion (r = -0.39). The association of choroidal thickness with CKD was confirmed in multiple logistic regression analyses once the effects of age and other confounding variables were accounted for. The odds ratio of having early-stage CKD associated with a standard deviation increase in overall choroidal thickness was 0.43 (0.24-0.75, 95% confidence interval; p = 0.007). In conclusion, our study confirms the close relationships between changes in ocular microcirculation and renal dysfunction.

This paper presents an extensive performance analysis of open-ended waveguide elements for direct radiating arrays with a high scan angle (±50° /60°). The evaluated designs are based on square and hexagonal apertures loaded with ridges. Both square and triangular lattices are considered in the framework of Ka-band downlink design requirements for future LEO mega-constellations. The parameter space defined by the monomodal condition has been explored to find an optimum value for each structure. The analyses carried out with both infinite and finite full-wave models in terms of active reflection coefficient, scan loss and cross-polar discrimination are in good agreement.

In this work, the design of a convex conformal reflectarray (CRA), suitable to be used for high gain on board antenna in mobile communication systems, is presented. The reflector is not planar, as in usual reflectarray configurations, but the re-radiating elements are printed on a surface conformed to a cylinder to mimic a curved surface, such as the fuselage of an airplane, on which the reflectarray could be mounted. To compensate for the loss in efficiency due to the curvature, an ad hoc feed is designed; the results obtained with the simulation of the entire structure and the measurements of its prototype prove the effectiveness of the design procedure and its capability in enhancing the CRA features, in comparison with similar but more conventional solutions.

Antimicrobial resistance (AMR) is a major challenge of the 21st century. Digital technologies are now an increasingly effective means of supporting optimal health care delivery and public health. The aim of this study was to explore the apps available to support health care professionals in the fight against AMR. A total of 4 independent researchers conducted a systematic search of the App Store and Google Play Store using the following keywords: \"antimicrobial resistance,\" \"antibiotic resistance,\" \"antimicrobial stewardship,\" \"antibiotic stewardship,\" \"antibiotic guide,\" \"antibiotic therapy,\" and \"antimicrobial therapy.\" The same keywords were also searched in Italian. The apps whose contents were in languages other than Italian or English, or apps which were games, or had multimedia or paid content and advertising, or apps for only specific pathologies were not considered. A set of basic information was collected for all apps found. After downloading the apps, they were evaluated using an 86-item checklist containing expert-validated criteria aggregated in the domains of pathogens and etiological agents, diagnosis and therapy support, AMR, dashboard function, antimicrobial stewardship (AMS), notes and recordings, network, and technical characteristics of the app. First, 115 apps were identified: 31 apps for Android and 84 apps for iOS. By applying the exclusion criteria, 31 apps were excluded (16 for Android and 15 for iOS) for the following reasons: not available in Italian or English (6 apps), not freely available (14 apps), required registration (5 apps), and games (6 apps). The remaining 84 eligible apps (15 for Android and 69 for iOS) were downloaded, installed, and further analyzed using the same criteria, excluding 57 apps (48 for iOS and 9 for Android) for the following reasons: required further registration (16 apps), language other than Italian or English (17 apps), pathology specific (5 apps), paid content (8 apps), specific to veterinarians (4 apps), recreational apps (2 apps), referred to only scientific articles (1 app), no longer available (1 app), and not health care objectives (3 apps). The remaining 27 apps (6 for Android and 21 for iOS) were selected for in-depth analysis. Of the 27 apps that met the inclusion criteria, most apps did not fulfill the desirable aspects and only 2 of them achieved a fulfillment score of 36%. The highest scores were achieved for support for diagnosis and therapy (37%) and technical characteristics of the app (23%). Lower scores were achieved for AMS (8%), pathogens and etiological agents (4%), notes and records (3%), network (2%), AMR (1%), and dashboard function (1%). None of the apps examined successfully provided the desired features and functions. To better engage of prescribers in the fight against AMR, the development of an app that meets the requirements is needed.

Low-frequency (<300 MHz) aperture array systems are one of the new trends in modern radio astronomy. Among the challenges they pose, the instrumental calibration is a key aspect requiring an accurate and reliable model of each element of such electrically large array. A full-wave electromagnetic analysis has been carried out for the lower frequency (30–80 MHz) array of the low frequency array (LOFAR) radio telescope taking into account the presence of soil ground, the mutual coupling between the antennas and the relevant receiver impedance loading effects. The impact of mutual coupling effects on the embedded element and array patterns is assessed for two subarray configurations with different degrees of sparseness. A simplistic array factor approach has been implemented as well to determine the accuracy in the antenna pattern evaluation with respect to the full-wave approach. Finally, results from an experimental campaign conducted by means of a micro hexacopter system show the reliability of the developed array numerical model.

Characteristic Modes Analysis (CMA) is a widely used method with recent progress in multi-antenna systems. We employ this method to characterize the mutual coupling phenomenon between two SKALA4.1 antennas, the low-frequency array elements of the future radiotelescope Square Kilometer Array (SKA-Low). The CMA accuracy is first validated at the lowest frequency range of interest with respect to a standard Method of Moments (MoM) solution by decomposing the single antenna into its characteristic modes. We then examine critical frequencies of a two-antenna system in modal decomposition, and characterize those responsible for the radiated electric field spurious spectral features owing to the mutual coupling. We connect these modes to first-order coupling of single antenna CMA modes, by using the eigenvalue data of both single- and two- antenna simulations.

In order to enhance the accuracy of the complex permittivity data employed in Ground Penetrating Radar (GPR) techniques, an adaptive cavity setup is presented. The use of moveable walls permits to relax the mechanical constraints on the sample dimensions so that it can be employed also in complicate measurement condition as, for example, in the case of wet samples. Moreover, exploiting the cavity resonance phenomenon, low loss materials, such as some type of marbles, can be accurately evaluated. The numerical characterization, the parametric analyses and the L-band measurement results show the validity and the reliability of this configuration.

Motivated by the challenges of future 6G communications where terahertz (THz) frequencies, intelligent reflective surfaces (IRSs) and ultra-wideband (UWB) signals coexist, we analyse and propose a set of efficient techniques for configuring the IRS when the signal bandwidth is a significant fraction of the central frequency (up to 50%). To the best of our knowledge this is the first time that IRS configuration techniques are analyzed for such huge bandwidths. In our work we take into account for the channel model, the power spectral density of the signal reflected by the IRS and the network geometry. We evaluate the proposed solutions in terms of achievable rate and compare it against an upper bound we derived. Our results hint rules for designing IRS-aided communication systems and allow to draw conclusions on the trade-off between performance and complexity required for configuring the IRS.

We consider the optimization of a smart radio environment where meta-surfaces are employed to improve the performance of multiuser wireless networks working at sub-THz frequencies. Motivated by the extreme sparsity of the THz channel we propose to model each meta-surface as an electronically steerable reflector, by using only two parameters, regardless of its size. This assumption, although suboptimal in a general multiuser setup, allows for a significant complexity reduction when optimizing the environment and, despite its simplicity, is able to provide high communication rates. We derive a set of asymptotic results providing insight on the system behavior when both the number of antennas at the transmitter and the meta-surfaces area grow large. For the optimization we propose an algorithm based on the Newton-Raphson method and a simpler, yet effective, heuristic approach based on a map associating meta-surfaces and users. Through numerical results we provide insights on the system behavior and we assess the performance limits of the network in terms of supported users and spatial density of the meta-surfaces.

The Large Scale Polarization Explorer (LSPE) project, funded by the Italian Space Agency (ASI), includes the development of LSPE-Strip, a ground-based radio telescope for observing Cosmic Microwave Background (CMB) anisotropies. LSPE-Strip, nearing its construction phase, will operate from the Teide Observatory in Tenerife, employing 49 coherent polarimeters at 43 GHz to deliver critical data on CMB anisotropies and 6 channels at 95 GHz as atmospheric monitor. On-site characterization of such advanced instruments is crucial to detect possible systematic effects, such as gain fluctuations, beam distortions, and pointing errors, that can compromise performance by introducing spurious polarizations or radiation collection from unintended directions. To address these challenges, a drone-mounted Q-band test source for on-site characterization of LSPE-Strip's polarimeter array was developed. Modern Unmanned Aerial Vehicles (UAVs) offer a flexible approach for antenna pattern measurements, yet their use in high-frequency radio astronomy is not consolidated practice. In October 2022, a UAV-based measurement campaign was conducted with the TFGI instrument on the second QUIJOTE telescope in Tenerife, in collaboration with the Instituto de Astrofisica de Canarias. This pioneering effort aimed to validate UAV-based beam characterization methods and assess QUIJOTE's performance under operational conditions. Preliminary results demonstrated high measurement accuracy, leveraging QUIJOTE's dual-receiver configuration for beam validation. These findings provide valuable insights for optimizing UAV systems in preparation for LSPE-Strip's future characterization.