Optical characterisation and study of ex vivo glioma tissue for hyperspectral imaging during neurosurgery

In recent years, hyperspectral imaging (HSI) has demonstrated the capacity to non-invasively differentiate tumours from healthy tissues and identify cancerous regions during surgery, particularly for glioma resection. This is thanks to the use of a relatively large number of adjacent wavelength bands, in order to reconstruct full reflectance spectra of each pixel in the acquired images of the target, thus providing information about its morpho-chemical composition. However, current HSI analysis approaches seem not to fully exploit such advantage, since they mostly tend to focus on tissue features recognition and cancer identification based on supervised algorithm trained upon diagnostic evaluations made by the neurosurgeons or from other diagnostic tools (e.g., histopathology). There is indeed a lack of proper broad-range, optical characterisation of tumour tissue, specifically gliomas, which could provide a more objective, comprehensive and quantitative insight in the spectro-chemistry of the tumour itself and help identifying novel biomarkers for cancer imaging via HSI. For this purpose, we present a fully optical characterisation of fresh ex vivo samples of glioma from surgical biopsies using both a laboratory spectrophotometer and an in-house, high-spectral density HSI system. The latter is based on spectral scanning of the samples via supercontinuum laser (SCL) illumination filtered with acousto-optic tunable filters (AOTF). The results of the spectral characterisation are analysed and compared to extract optical signatures for potential glioma biomarkers in order to further aid neuronavigation via HSI during glioma resection, in particular in the framework of our recently started HyperProbe project

Synthesis of Specimen Preparation and Curing Processes for Cold Recycled Asphalt Mixes

The process of cold recycling (CR) is becoming method of choice for pavement rehabilitation due to significantly added environmental and economic benefits. Understanding and standardization of specimen preparation and curing processes are critical to replicate field conditions in lab. This paper presents an extensive synthesis of various specimen preparation and curing processes for cold recycled asphalt mixes. Topics synthesized include RAP, emulsion/bitumen and aggregate preparation, mixing processes, pre- and post- compaction curing, compaction and mechanical testing. This paper was developed through efforts of cold recycling task group (TG6) of RILEM Technical Committee on Testing and Characterization of Sustainable Innovative Bituminous Materials and Systems (TC-SIB)

Preparation and immunogenicity of gold glycol-nanoparticles as anti-pneumococcal vaccine model

Capsular polysaccharides (CPS) of encapsulated bacteria are critical determinants of bacterial virulence and have been used in the development of protective conjugate vaccines. Nanomaterials loaded with carbohydrate antigens are emerging as promising synthetic vaccine candidates, alternative to classic polysaccharide/protein conjugate vaccines. Repetitive antigen display, the ability to potentiate immune responses through enhanced antigen delivery to the immune system and the possibility to tune the loading of well-defined carbohydrates on different scaffolds are key factors supporting nanotechnology-based vaccines. Moreover, other structures can be incorporated onto the nanosystems as active mediators to increase vaccine efficacy. In this context, gold glyco-nanoparticles (GNPs) functionalized with the synthetic tetrasaccharide repeating unit of Streptococcus pneumoniae serotype 14 (Pn14PS), and the peptide fragment OVA323-339, serving as a T-helper epitope, have been demonstrated as able to elicit in vivo specific and functional IgG antibodies against native Pn14PS, thus promoting uptake and killing of bacteria Pn14.[1] Herein, we report the preparation and immunological evaluation of new GNPs containing two synthetic CPS fragments related to serotypes 19F and 14 of Streptococcus pneumoniae (Tri-19F and Tetra-14) simultaneously displayed on nanoparticle surface, together with the T-helper peptide fragment OVA323-339. We aimed to explore the effect of these GNPs, coated with different antigen patterns, on the immunological response in mice and whether this response is affected by the presence of both saccharide antigens from diverse bacterial serotypes loaded onto the same nanoparticle. The main goal of this study was to determine whether these GNPs could induce specific antibodies against CPSs of both pneumococcal serotypes 14 and 19F or to affect the immune activity of either of them. Mice immunization showed that the concomitant presence of Tri-19F and Tetra-14 on the same nanoparticle critically enhanced the titers of specific IgG antibodies towards type 14 polysaccharide compared to GNP exclusively displaying Tetra-14. We also found that the bi-antigenic GNPs induced anti-Pn14PS IgG antibodies titers of the same order of magnitude as the currently used PCV13 human vaccine

Glyconanoparticles for colorimetric bioassays

Carbohydrate molecules are involved in many of the cellular processes that are important for life. By combining the specific analyte targeting of carbohydrates with the multivalent structure and change of solution colour as a consequence of plasmonic interactions with the aggregation of metal nanoparticles, glyconanoparticles have been used extensively for the development of bioanalytical assays. The noble metals used to create the nanocore, the methodologies used to assemble the carbohydrates on the nanoparticle surface, the carbohydrate chosen for each specific target, the length of the tether that separates the carbohydrate from the nanocore and the density of carbohydrates on the surface all impact on the structural formation of metal based glyconanoparticles. This tutorial review highlights these key components, which directly impact on the selectivity and sensitivity of the developed bioassay, for the colorimetric detection of lectins, toxins and viruses

Recent advances on smart glycoconjugate vaccines in infections and cancer

Vaccination is one of the greatest achievements in biomedical research preventing death and morbidity in many infectious diseases through the induction of pathogen-specific humoral and cellular immune responses. Currently, no effective vaccines are available for pathogens with a highly variable antigenic load, such as the human immunodeficiency virus or to induce cellular T-cell immunity in the fight against cancer. The recent SARS-CoV-2 outbreak has reinforced the relevance of designing smart therapeutic vaccine modalities to ensure public health. Indeed, academic and private companies have ongoing joint efforts to develop novel vaccine prototypes for this virus. Many pathogens are covered by a dense glycan-coat, which form an attractive target for vaccine development. Moreover, many tumor types are characterized by altered glycosylation profiles that are known as “tumor-associated carbohydrate antigens”. Unfortunately, glycans do not provoke a vigorous immune response and generally serve as T-cell-independent antigens, not eliciting protective immunoglobulin G responses nor inducing immunological memory. A close and continuous crosstalk between glycochemists and glycoimmunologists is essential for the successful development of efficient immune modulators. It is clear that this is a key point for the discovery of novel approaches, which could significantly improve our understanding of the immune system. In this review, we discuss the latest advancements in development of vaccines against glycan epitopes to gain selective immune responses and to provide an overview on the role of different immunogenic constructs in improving glycovaccine efficacy

Kinetic evolution of the perpendicular turbulent cascade in the solar wind

We investigate the solar-wind dynamics at typical kinetic scales resulting from a turbulent cascade along the direction strictly perpendicular to a background magnetic field. We use a hybrid Vlasov-Maxwell numerical model that solves Vlasov equation for the proton distribution function. Electrons are assumed as an isothermal fluid. We find, over a range of about four decades of wavenumbers, a Kolmogorov slope at wavelengths larger than the proton inertial scale and an abrupt change in the scaling law across the proton inertial length. The energy is carried along the cascade in the form of magneto-sonic fluctuations while the short-scale termination of the spectra is dominated by a significant level of electrostatic activity. As a result of the turbulent energy cascade, we observe the generation of shock structures where the proton distribution function departs from the Maxwellian equilibrium configuration displaying the presence of beams of accelerated protons. Finally, quasi-static magnetic-field structures are produced in the early stage of the system dynamics and remain stable up to the end of the simulation. The numerical results discussed in the present paper qualitatively reproduce a complex phenomenology frequently recovered by spacecraft observations. Copyright (C) EPLA, 201

I materiali lapidei versiliesi. La qualificazione per l'utilizzo nei sistemi di pavimentazione

Questa pubblicazione nasce da un progetto di ricerca svolto negli anni 2010 e 2011 presso il Dipartimento di Ingegneria Civile e il Dipartimento di Scienze della Terra dell’Università di Pisa. Il progetto è stato cofinanziato dalla Fondazione della Cassa di Risparmio di Lucca che si ringrazia, insieme al COSMAVE - Consorzio per lo sviluppo dell’attività marmifera della Versilia, per il sostegno e per il contributo alla diffusione dei risultati. Lo scopo della ricerca multidisciplinare presentata in questo volume è stato quello di approfondire, con prove tecnologiche, le indagini sperimentali relative alle caratteristiche prestazionali di tipo strutturale e funzionale (dalla caratterizzazione petrografica alla determinazione delle proprietà fisiche e meccaniche) su una casistica di materiali lapidei commerciali presenti nell’area Versiliese, al fine di evidenziare le correlazioni esistenti tra i dati ottenuti con i vari metodi di indagine proposti. La campagna di prove e i dati raccolti hanno consentito di valutare al meglio quanto i parametri naturali influenzino le effettive prestazioni in opera dei materiali da impiegare nelle pavimentazioni. Con il nostro lavoro speriamo di avere contribuito alla definizione di soglie minime oggettive per l’inserimento dei materiali lapidei nei capitolati relativi alle pavimentazioni nel settore delle costruzioni, che consentano anche la creazione di un’offerta commerciale corretta e consapevole per affrontare le future sfide dei mercati

Kinetic evolution of the perpendicular turbulent cascade in the solar wind

We investigate the solar-wind dynamics at typical kinetic scales resulting from a turbulent cascade along the direction strictly perpendicular to a background magnetic field. We use a hybrid Vlasov-Maxwell numerical model that solves Vlasov equation for the proton distribution function. Electrons are assumed as an isothermal fluid. We find, over a range of about four decades of wavenumbers, a Kolmogorov slope at wavelengths larger than the proton inertial scale and an abrupt change in the scaling law across the proton inertial length. The energy is carried along the cascade in the form of magneto-sonic fluctuations while the short-scale termination of the spectra is dominated by a significant level of electrostatic activity. As a result of the turbulent energy cascade, we observe the generation of shock structures where the proton distribution function departs from the Maxwellian equilibrium configuration displaying the presence of beams of accelerated protons. Finally, quasi-static magnetic-field structures are produced in the early stage of the system dynamics and remain stable up to the end of the simulation. The numerical results discussed in the present paper qualitatively reproduce a complex phenomenology frequently recovered by spacecraft observations