A New Approach to the Link Budget Concept for an OAM Communication Link

Following on from the increasing interest for electromagnetic waves carrying Orbital Angular Momentum (OAM), different configurations of antenna systems able to generate such beams have been proposed. However, in our opinion, a traditional radiation pattern approach does not provide the right picture of an OAM-based communication link. For this reason we propose a new general concept, the "OAM-link pattern", which takes into account the peculiar phase structure characterizing these waves. Focusing on OAM transmissions between antenna arrays, we introduce a formula for the link budget evaluation which describes the whole communication link and directly leads to a "classically shaped" main lobe pattern for a proper rephased reception in the case of uniform circular arrays.Comment: 4 pages, 3 figure

OAM multiple transmission using uniform circular arrays: numerical modeling and experimental verification with two digital television signals

In this work we present the outcomes of a radio-frequency OAM transmission between two antenna arrays performed in a real-world context. The analysis is supplemented by deep simulative investigations able to provide both a preliminary overview of the experimental scenario and a posteriori validation of the achieved results. As a first step, the far-field OAM communication link is tested at various frequencies and the corresponding link budget is studied by means of an angular scan generated by the rotation of the receiving system. Then, on the same site, two digital television signals encoded as OAM modes ($\ell$=1 and $\ell$=-1) are simultaneously transmitted at a common frequency of 198.5 MHz with good mode insulation.Comment: 16 pages, 14 figure

HIV-1 gp120 influences the expression of microRNAs in human monocyte-derived dendritic cells via STAT3 activation

Background: MicroRNAs (miRs) are an abundant class of small non-coding RNAs (~22 nt) that reprogram gene ex- pression by targeting mRNA degradation and translational disruption. An emerging concept implicates miR coup- ling with transcription factors in myeloid cell development and function, thus contributing to host defense and inflammation. The important role that these molecules play in the pathogenesis of HIV-1 is only now emerging. Results: We provide evidence that exposure of monocyte-derived dendritic cells (MDDCs) to recombinant HIV-1 R5 gp120, but not to CCR5 natural ligand CCL4, influences the expression of a panel of miRs (i.e., miR-21, miR-155 and miR-181b) regulated by STAT3 and potentially targeting genes belonging to the STAT3 signaling pathway. The blockage of gp120-induced STAT3 activation impairs gp120 capacity to modulate the expression level of above mentioned miRs. Predictive analysis of miR putative targets emphasizes that these miRs share common target genes. Furthermore, gene ontology and pathway enrichment analysis outline that these genes mainly belong to biological processes related to regulation of transcription, in a complex network of interactions involving pathways relevant to HIV-DC interaction. Conclusions: Overall, these results point to gp120-triggered modulation of miR expression via STAT3 activation as a novel molecular mechanism exploited by HIV-1 to affect DC biology and thus modulate the immune response through complex regulatory loops involving, at the same time, miRs and transcription factors

A Modal Choice Model for Evaluating the Impact of Increasing Automation in Container Terminals

The aim of this paper is to define a model for the modal choice between road and rail transport taking into account the increase of rail attractiveness resulting from the increasing of the number of container terminals equipped with automated handling systems. The considered automated handling system is the automated multilevel handling system developed within the RCMS EU project, that is, a multistory storage building, equipped with electric AGVs, remote controlled elevators and remote controlled ceiling cranes. This automated system makes possible to access to a specific container without the necessity of reshuffling and to load/unload containers to/from trucks and trains directly under the storage structure, allowing a significant reduction of the loading/unloading time. In order to define the modal choice model, the systematic utility and the perceived utility are provided and the flows of freight delivered via rail or via road are determined with a binomial Logit model. Moreover, the threshold distance between seaport and inland terminals beyond which automation has a significant impact on modal split is evaluated. As a case study, a European port hinterland network is considered and some scenarios are analyzed, assuming that an increasing number of terminals introduces automation. The paper shows that the introduction of automation in container terminals has significant consequences on modal split. In particular, as the number of automated terminals increases, the rail mode becomes more competitive and the threshold distance between seaport and inland terminals, at which the modal split is equally distributed between road and rail modes, significantly decreases

Modeling Orbital Angular Momentum (OAM) Transmission in Waveguides with the COMSOL Multiphysics® Software

The recent years have witnessed a growing interest in the possibility of enhancing the information transfer per unit bandwidth by exploiting the Orbital Angular Momentum (OAM) of light in both free-space and guided scenarios. In the proposed paper, the propagation of suitable OAM superpositions of waveguide eigenmodes in guiding structures with a circular symmetry is analyzed both theoretically and with the aid of the software COMSOL Multiphysics®, leading to the estimation of the power attenuation constants due to the finite conductivity of the metallic guide walls

Hyperspectral Chemical Imaging of Single Bacterial Cell Structure by Raman Spectroscopy and Machine Learning

6openopenBarzan, Giulia; Sacco, Alessio; Mandrile, Luisa; Giovannozzi, Andrea Mario; Portesi, Chiara; Rossi, Andrea MarioBarzan, Giulia; Sacco, Alessio; Mandrile, Luisa; Giovannozzi, Andrea Mario; Portesi, Chiara; Rossi, Andrea Mari

PLANTAR PRESSURE DISTRIBUTION DURING RUNNING IN DIFFERENT SURFACES: PRELIMINARY STUDY

Overuse injuries in running have been linked to a rigid surface; on the other hand, acute injuries are considered multifactor, since a combination of running speed, surface, shoes, fatigue and training is involved (Walker, 2005). Many stress fractures are due to cumulative impact shock, which is believed to be greater on a hard surface like concrete (Feehery, 1986).The purpose of this study was to compare plantar pressure (PP) distribution on 4 different surfaces. The hypothesis was that surfaces considered rigid would present smaller contact time and greater values in plantar pressure variables in all foot areas; and surfaces considered compliant would present greater contact time and smaller values for the same variables

Silver-containing antimicrobial membrane based on chitosan-TPP hydrogel for the treatment of wounds

Treatment of non-healing wounds represents hitherto a severe dilemma because of their failure to heal caused by repeated tissue insults, bacteria contamination and altered physiological condition. This leads to face huge costs for the healthcare worldwide. To this end, the development of innovative biomaterials capable of preventing bacterial infection, of draining exudates and of favoring wound healing is very challenging. In this study, we exploit a novel technique based on the slow diffusion of tripolyphosphate for the preparation of macroscopic chitosan hydrogels to obtain soft pliable membranes which include antimicrobial silver nanoparticles (AgNPs) stabilized by a lactose-modified chitosan (Chitlac). UV-Vis and TEM analyses demonstrated the time stability and the uniform distribution of AgNPs in the gelling mixture, while swelling studies indicated the hydrophilic behavior of membrane. A thorough investigation on bactericidal properties of the material pointed out the synergistic activity of chitosan and AgNPs to reduce the growth of S. aureus, E. coli, S. epidermidis, P. aeruginosa strains and to break apart mature biofilms. Finally, biocompatibility assays on keratinocytes and fibroblasts did not prove any harmful effects on the viability of cells. This novel technique enables the production of bioactive membranes with great potential for the treatment of non-healing wounds