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Cell responses to varying electric fields can reveal insights on cell biology with important implications for pharmaceutical and basic research. In this work, we exploit spectral information content in Opto-Electronic Tweezers (OET) systems through machine learning for label-free characterization of cell dielectric properties aimed at cell classification and drug response evaluation. A customized Polymethyl-methacrylate (PMMA) chip with ITO substrates and an a-Si layer was designed for OET-based manipulation of cells and integrated with an inverted microscope. We obtained OET cell signatures as spectra responses of kinematic and dynamic descriptors, which are the result of time-lapse measurements at increasing frequencies of the OET. Machine learning algorithms enable automatic selection and characterization of the information content present in the OET signature so derived. Experiments are performed on three biological case studies, involving 1) the discrimination of cell types among U937 human leukemia cells, PC-3 human prostate cancer cells and HaCaT human immortalized keratinocytes; 2) the evaluation of the effects of the chemotherapeutic agent etoposide on U937 cells at different concentrations; and 3) the evaluation of the effects of different exposure times of etoposide on U937 cells. The obtained results demonstrate that multiple levels of dielectric information can be extracted via OET cell signatures and clearly pose OET as a promising tool for cell discrimination and drug response evaluation.

Environmental monitoring is a growing concern in both developed and non-developed countries across the globe, because of the strong impact of several anthropogenic activities on both human and planet health. Air quality monitoring is usually performed with specialized equipment and analytical methods by regulatory agencies and researchers. However, in order to obtain more realistic and continuous results on the situation of pollutants distribution, EU projects guidelines report the need to involve also citizens in environmental monitoring, thus low-cost and easy-to-use technologies are required. To achieve this aim, novel sensors for environmental monitoring have been designed and developed to date to obtain reliable values comparable to those provided by standard methods and technologies. Currently, electrospinning is considered as one of the most versatile and inexpensive manufacturing technologies to design and develop nanostructured sensors to detect gases and volatile organic compounds (VOCs) in the air [1]. Sensors based on polymeric fibers look extremely attractive for the low cost and great versatility of the raw materials that can be easily tunable, according to the transducer used and the application of interest, taking part to the resulting sensing features (selectivity and sensitivity). Therefore, electrospun nanofibrous and environmentally friendly materials have been designed and fabricated for detecting some atmospheric pollutants. The attention has been focused on the challenging goal of obtaining conductive sensors for the monitoring of air pollutants employing suitable scaffolds of eco-friendly (polyhydroxybutyrate) [2] and sustainable (recycled) nanomaterials. Indeed biodegradability is a noteworthy feature to obtain sensing tools environmentally friendly and safe for health. However, sensors for gas monitoring must also be able to both persist intact for a useful shelf life and to preserve their sensing features over time, depending on the specific application and the working period. There are operative conditions where biodegradable polymers cannot be reasonably used. In these cases, some recycled plastics (as PS) can be used to develop more durable sensing materials suitable and selective for optically/electrically active molecules/particles, according to a sustainable approach. Finally, the selectivity of fibers can be tuned by introducing differently functionalized macromolecules that are sensitive to several classes of gas and VOCs. Therefore, some heterocyclic compounds (Me-tetraphenylporphyrins) [3] that resembles naturally occurring porphyrins, have been synthesized and solubilized within selected polymer blends solutions and subjected to electrospun deposition on interdigitated metal electrodes. The conductivity of the planned sensors has been implemented by adding conductive nanoparticles (e.g. graphene's flakes) in the ES-solution. The novel sensors resulted sensitive to several gas (i.e. NH3, NO2) and VOCs (i.e. aromatic hydrocarbons) with different selectivity, reporting promising sensing features potentially useful for environmental pollution monitoring.

When films of zinc 5-(4-carboxyphenyl),10,15,20-triphenyl porphyrin (ZnTPP) are exposed to waterborne amine in pH- neutral or alkaline media, both Q- band and Soret band respond with a change of absorbance due to the donation of amine ‘lone pair’ electrons to the metalloprophyrin π orbital. However, this is difficult to reveal with a conventional spectrometer even under high amine concentration. We therefore introduce optical fibres coated with ZnTPP into a bespoke ‘light balance’ evanescent wave absorbance meter [doi:10.1016/j.snb.2016.05.065]. The light balance makes absorbance changes clearly visible under only 5 μM aqueous amine, making PVC membranes redundant. We find sensitivity is higher, and limit- of- detection lower, in the Soret band rather than the Q- band, reflecting the stronger Soret band absorbance. Also, we find that sensitivity is higher, and limit- ofdetection approximately two times lower, when rough rather than smooth fibres are used. We believe the rough fibre surface leads to enhanced evanescence, and therefore better overlap of the wave propagating in the fibre with the ZnTPP fibre cladding. We find a limit of detection to waterborne amines below 1 μM, which compares well to other sensors for waterborne amines [Korent, S.M. et.al. Anal. Bioanal. Chem. 387 (2007) 2863–2870; Algarni, S. A. et.al. Talanta 153 (2016) 107–110]. We therefore recommend ‘rough guide’ evanescent wave optrodes, in combination with sensitive ‘light balance’ detector, to succeed membrane- embedding of colorimetric sensitisers such as metalloporphyrines.

Systems designed by humans have no "intelligence" and only execute algorithms; however, they may, somehow, mimic an intelligent behaviour (smart systems). Since, at present, information management in the electrical energy domain is extremely advantageous, smart systems require, all together, sensors, actuators, and electronic interfaces. In literature there is some confusion, and even some contradiction, between the parameters used for characterizing the properties of sensors and of electronic interfaces. In the first part of the paper we provide a unified, coherent set of definitions which may be applied to both sensors and electronic interfaces. Afterwards we show how non-electrical systems may be conveniently analysed in the electrical domain by means of equivalent circuits, and we review some techniques for the design of high performance electronic interfaces; finally, we show a few examples, which illustrate the use of those techniques in practical applications

High sensitivity and cross-selectivity are mandatory properties for sensor arrays. Although metalloporphyrins and pH indicators are among the most common and appropriate choices for the preparation of optical sensor arrays, the sensitivity spectrum of these dyes is limited to those analytes able to induce an optical response. To extend the receptive field of optical sensors, we explore the design of composite materials, where the molecular interaction among the subunits enriches their sensing working mechanisms. We demonstrate that blends of single metalloporphyrins and pH indicators, tested with a transduction apparatus based on ubiquitous and easily available hardware, can be endowed with sensing properties wider than those of single constituents, enabling the recognition of a broad range of volatiles.

Il capitolo risponde alle domande più comunemente rivolte agli specialisti sugli effetti del bilinguismo e la relazione con gli apprendimenti e lo sviluppo cognitivo e affettivo.

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Cancer cells and non-cancer cells differ in their metabolism and they emit distinct volatile compound profiles, allowing to recognise cancer cells by their scent. Insect odorant receptors are excellent chemosensors with high sensitivity and a broad receptive range unmatched by current gas sensors. We thus investigated the potential of utilising the fruit fly's olfactory system to detect cancer cells. Using in vivo calcium imaging, we recorded an array of olfactory receptor neurons on the fruit fly's antenna. We performed multidimensional analysis of antenna responses, finding that cell volatiles from different cell types lead to characteristic response vectors. The distances between these response vectors are conserved across flies and can be used to discriminate healthy mammary epithelial cells from different types of breast cancer cells. This may expand the repertoire of clinical diagnostics, and it is the first step towards electronic noses equipped with biological sensors, integrating artificial and biological olfaction.

E' la sintesi dei dati del Progetto Acquasense

The lipid phosphatase Ship2 is a protein that intervenes in several diseases such as diabetes, cancer, neurodegeneration, and atherosclerosis. It is made up of a catalytic domain and several protein docking modules such as a C-terminal Sam (Sterile alpha motif) domain. The Sam domain of Ship2 (Ship2-Sam) binds to the Sam domains of the EphA2 receptor (EphA2-Sam) and the PI3K effector protein Arap3 (Arap3-Sam). These heterotypic Sam-Sam interactions occur through formation of dimers presenting the canonical "Mid Loop/End Helix" binding mode. The central region of Ship2-Sam, spanning the C-terminal end of a2, the a3 and a4 helices together with the a2a3 and a3a4 interhelical loops, forms the Mid Loop surface that is needed to bind partners Sam domains. A peptide encompassing most of the Ship2-Sam Mid Loop interface (Shiptide) capable of binding to both EphA2-Sam and Arap3-Sam, was previously identified. Here we investigated the conformational features of this peptide, through solution CD and NMR studies in different conditions. These studies reveal that the peptide is highly flexible in aqueous buffer, while it adopts a helical conformation in presence of 2,2,2-trifluoroethanol. The discovered structural insights and in particular the identification of a helical motif, may lead to the design of more constrained and possibly cell permeable Shiptide analogs that could work as efficient antagonists of Ship2-Sam heterotypic interactions and embrace therapeutic applications. © 2014 Wiley Periodicals, Inc. Biopolymers 101: 1088-1098, 2014. © 2014 Wiley Periodicals, Inc.

Among the numerous applications of electronic nose technology, the analysis of foodstuff is one of the most promising and also the most travelled road towards industrial applications. On the other hands, since human senses are strongly involved in the interaction with foods the analysis of food provides an excellent field to compare the performances of natural and artificial olfaction systems. The electronic nose, being non-destructive and, in principle, directly correlated with the consumer perceptions, is a good candidate to develop quality evaluation tools for quality assessment. In this paper, the application of electronic nose to the evaluation of quality of foods is discussed. As selected example, the measure of quality of fruit is outlined. The experiments described have been performed with an electronic nose developed by the authors and of which a description is also given.

This paper introduces some preliminary consideration on non uniform resistance changes in silicon square photoconductors resulting when the surface exploration is made by small spot laser light. These results seem to be similar to those obtained from a chemically sensitive material such as, for instance SnO(2) left in air at a suitable temperature, for which the resistance decrease in presence of CO. A simple theory is considered for the determination of the approximated overall resistance value of a thermistor (or chemically sensitive thermistor) on the basis of sensitive sites localization.