Multidimensional spectral analysis of the ultrasonic radiofrequency signal for characterization of media

AbstractThe importance of the analysis of the radiofrequency signal is by now recognized in the field of tissue characterization via ultrasound. The RF signal contains a wealth of information and structural details that are usually lost in the B-Mode representation. The HyperSPACE (Hyper SPectral Analysis for Characterization in Echography) algorithm presented by the authors in previous papers for clinical applications is based on the radiofrequency ultrasonic signal. The present work describes the method in detail and evaluates its performance in a repeatable and standardized manner, by using two test objects: a commercial test object that simulates the human parenchyma, and a laboratory-made test object consisting of human blood at different dilution values. In particular, the sensitivity and specificity in discriminating different density levels were estimated. In addition, the robustness of the algorithm with respect to the signal-to-noise ratio was also evaluated

Bridging the gap between omics and earth system science to better understand how environmental change impacts marine microbes

The advent of genomic-, transcriptomic- and proteomic-based approaches has revolutionized our ability to describe marine microbial communities, including biogeography, metabolic potential and diversity, mechanisms of adaptation, and phylogeny and evolutionary history. New interdisciplinary approaches are needed to move from this descriptive level to improved quantitative, process-level understanding of the roles of marine microbes in biogeochemical cycles and of the impact of environmental change on the marine microbial ecosystem. Linking studies at levels from the genome to the organism, to ecological strategies and organism and ecosystem response, requires new modelling approaches. Key to this will be a fundamental shift in modelling scale that represents micro-organisms from the level of their macromolecular components. This will enable contact with omics data sets and allow acclimation and adaptive response at the phenotype level (i.e. traits) to be simulated as a combination of fitness maximization and evolutionary constraints. This way forward will build on ecological approaches that identify key organism traits and systems biology approaches that integrate traditional physiological measurements with new insights from omics. It will rely on developing an improved understanding of ecophysiology to understand quantitatively environmental controls on microbial growth strategies. It will also incorporate results from experimental evolution studies in the representation of adaptation. The resulting ecosystem-level models can then evaluate our level of understanding of controls on ecosystem structure and function, highlight major gaps in understanding and help prioritize areas for future research programs. Ultimately, this grand synthesis should improve predictive capability of the ecosystem response to multiple environmental drivers

HABITAT: An IoT Solution for Independent Elderly

In this work, a flexible and extensive digital platform for Smart Homes is presented, exploiting the most advanced technologies of the Internet of Things, such as Radio Frequency Identification, wearable electronics, Wireless Sensor Networks, and Artificial Intelligence. Thus, the main novelty of the paper is the system-level description of the platform flexibility allowing the interoperability of different smart devices. This research was developed within the framework of the operative project HABITAT (Home Assistance Based on the Internet of Things for the Autonomy of Everybody), aiming at developing smart devices to support elderly people both in their own houses and in retirement homes, and embedding them in everyday life objects, thus reducing the expenses for healthcare due to the lower need for personal assistance, and providing a better life quality to the elderly users

Serum Albumin Is Inversely Associated With Portal Vein Thrombosis in Cirrhosis

We analyzed whether serum albumin is independently associated with portal vein thrombosis (PVT) in liver cirrhosis (LC) and if a biologic plausibility exists. This study was divided into three parts. In part 1 (retrospective analysis), 753 consecutive patients with LC with ultrasound-detected PVT were retrospectively analyzed. In part 2, 112 patients with LC and 56 matched controls were entered in the cross-sectional study. In part 3, 5 patients with cirrhosis were entered in the in vivo study and 4 healthy subjects (HSs) were entered in the in vitro study to explore if albumin may affect platelet activation by modulating oxidative stress. In the 753 patients with LC, the prevalence of PVT was 16.7%; logistic analysis showed that only age (odds ratio [OR], 1.024; P = 0.012) and serum albumin (OR, -0.422; P = 0.0001) significantly predicted patients with PVT. Analyzing the 112 patients with LC and controls, soluble clusters of differentiation (CD)40-ligand (P = 0.0238), soluble Nox2-derived peptide (sNox2-dp; P < 0.0001), and urinary excretion of isoprostanes (P = 0.0078) were higher in patients with LC. In LC, albumin was correlated with sCD4OL (Spearman's rank correlation coefficient [r(s)], -0.33; P < 0.001), sNox2-dp (r(s), -0.57; P < 0.0001), and urinary excretion of isoprostanes (r(s), -0.48; P < 0.0001) levels. The in vivo study showed a progressive decrease in platelet aggregation, sNox2-dp, and urinary 8-iso prostaglandin F2 alpha-III formation 2 hours and 3 days after albumin infusion. Finally, platelet aggregation, sNox2-dp, and isoprostane formation significantly decreased in platelets from HSs incubated with scalar concentrations of albumin. Conclusion: Low serum albumin in LC is associated with PVT, suggesting that albumin could be a modulator of the hemostatic system through interference with mechanisms regulating platelet activation

Nuovi copolimeri anfifilici fluorurati: sintesi e studio delle proprietà di auto-assemblaggio in soluzione e in superficie

In questo studio di tesi, sono stati preparati nuovi copolimeri anfifilici statistici di struttura generale PEGMAx-co-AFy, e un copolimero anfifilico a due blocchi, di struttura generale PEGMAn-b-MAFm, attraverso la tecnica della polimerizzazione radicalica a trasferimento d’atomo (ATRP). L’avvenuta copolimerizzazione è stata confermata mediante le analisi di cromatografia di permeazione sul gel (GPC) e risonanza magnetica nucleare (1H NMR e 19F NMR). In particolare, di questi copolimeri anfifilici statistici e a blocchi è stata studiata la loro capacità di auto-assemblarsi in soluzione e in superficie. Per poter studiare i fenomeni di auto-assemblaggio in soluzione attraverso analisi di spettroscopia di fluorescenza, è stata legata covalentemene una sonda fluorescente a un copolimero statistico anfiflico (PEGMAx-co-AFy-co-JCBFz). Verificata la capacità dei copolimeri anfifilici sintetizzati di auto-assemblarsi in acqua, è stato attuato uno studio sull’influenza della temperatura su tali strutture complesse mediante analisi di spettroscopia di fluorescenza e misure di diffusione dinamica della luce (DLS). Infine i copolimeri anfifilici sono stati depositati in film sottili mediante spin-coating da soluzione. Di questi è stata analizzata la bagnabilità con acqua e esadecano, misurando i valori degli angoli di contatto (w, h). I film di PEGMAx-co-AFy-co-JCBFz sono stati testati come indicatori di fluorescenza sensibili all’esposizione di vapori di composti organici volatili (VOCs). In conclusione, i copolimeri anfifilici di questo lavoro dimostrano di soddisfare a molti dei prerequisiti di auto-assemblaggio richiesti per differenti potenziali applicazioni e incoraggiano a proseguire il loro studio più approfondito

Self-assembling behaviors of amphiphilic polymers: From unimer micelles in solutions to nanostructured surfaces in thin films

The PhD work was aimed to investigate novel types of amphiphilic synthetic polymers, where hydrophobic intramolecular interactions drive self-assembling into nanostructures in water solution and at the surface of thin solid films. In particular, attention was focused on the understanding of the morphology of self-assembled structures in relation to the nature of the hydrophobic component in the different polymers and to the variation of the temperature and concentration. To obtain a good control on the (co)polymerization the ARGET-ATRP and RAFT methods were used. In this way, we succeeded in preparing (co)polymers featuring diverse chemical architectures as well as tailored and varied philic/phobic balances. Three major classes of amphiphilic polymers were newly developed: i) Random copolymers of polyethyleneglycol methyl ether methacrylate (PEGMA) as an hydrophilic and thermoresposive component with perfluorohexylethyl acrylate (FA) or polydimethylsiloxane methacrylate (SiMA) as an hydrophobic component. Triethyleneglycol methyl ether methacrylate (TRIGMA) was also used as an alternate comonomer in order to depress hydrophilicity of the respective copolymers. ii) Homopolymers of hydrophobic tetrafluorostyrene monomers modified by inserting an oligoethylene segment with varied chain lengths. iii) Random copolymers based on hydrophilic zwitterionic phosphorylcholine methacrylate (MPC) or sulfobetaine methacrylate (MSA) with 3-(trimethoxysilyl)propyl methacrylate (PTMSi) and copolymers of an hydrophobic FA with PTMSi. Detailed characterization of the (co)polymers by dynamic light scattering (DLS), small angle X-ray scattering (SAXS) and small angle neutron scattering (SANS) measurements confirmed the formation of self-folded, intrachain nanostructures, or unimer micelles, for amphiphilic fluorinated copolymers of type i) in water solutions at room temperature. All polymers exhibited a reversible LCST-like behavior in water solutions, as identified by a transition temperature Tc that depended on the nature and composition of the amphiphilic polymers. The self-folded nanostructures clustered together into interchain aggregates above Tc, that quite reversibly collapsed back to unimer micelles on cooling below Tc. By contrast, all copolymers showed a conventional random coil conformation in organic solvents. A similar thermoresponsive behavior of intrachain nanostructures was observed with homopolymers of type ii), whose Tc was influenced by the overall hydrophobic/hydrophilic balance, as identified by the length of poliethylene glycol side chains. Fluorescent molecular probes were used to observe the self-assembly behavior of fluorinated amphiphilic copolymers. In particular, the single chain folding process was investigated through both a covalent functionalization and physical dispersion of two different hydrophobic dyes (2-cyano-2-[4-[vinyl(1-1’-biphenyl)-4’-yl]vinyljulolidine (JBCF) and coumarin 153 respectively) by fluorescence emission spectroscopy. The results of these preliminary analyses suggested the possibility of using the designed fluorinated copolymers as systems for controlled loading of hydrophobic molecules and possible release in response to a change in the embedding environments. Random copolymers of type iii) were developed in which the zwitterion monomers MPC or MSA and hydrophobic FA were combined with functional PTMSi for tethering on glass substrates, thereby creating functional supported films incorporating nanostructuring additives. Experiments by static contact angle measurements, X-ray photoelectron spectroscopy, surface zeta potential and fluorescence spectroscopy analyses were applied to prove the effective anchoring of the polymeric films on the glass substrate before and after immersion in water. Then, antifouling potential of the films was demonstrated in biological assays against the adhesion of the yeast pathogen Candida albicans, chosen as a model fungal microorganism. The fluorinated copolymers were much more able to reduce fungal adhesion than did the zwitterionic MPC and MSA polymers