696 research outputs found
A transistor based sensing platform and a microfluidic chip for a scaled-up simulation of controlled drug release
No full textThe framework of my thesis are Biomedical (or Biological) Microelectromechanical Systems (BioMEMSs). Two fields in which this discipline is involved are sensors and fluidics. Functionalized organic materials are under investigation to be the means for target biological sensing, and sensors are evolving to be integrated in fluidics platforms in order to produce in the future new small portable diagnostic devices. On the other hand one of the challenges of micro and nanofluidic technology is the fabrication of drug release devices, in order to control the amount of drug present in an organism. In this thesis these two arguments are considered. First we will discuss the implementation of a process oriented to the fabrication of an hybrid Organic Field Effect Transistor (OFET) with sensing capabilities from the semiconductive layer. In the second part we will show the fabrication process of a silicon based structure for the scaled-up characterization of drugs in nanochannels for controlled drug release. The characterization will consider charged microspheres playing the role of drugs to be tracked with a microscope. We will highlight also the possibility of implementing the transistor related technology in nanofluidic systems for the electronic controlled drug releas
Evidence of Negative Capacitance in Piezoelectric ZnO Thin Films Sputtered on Interdigital Electrodes
No full textThe scaling paradigm known as Moore's Law, with the shrinking of transistors and their doubling on a chip every two years, is going to reach a painful end. Another less-known paradigm, the so-called Koomey's Law, stating that the computing efficiency doubles every 1.57 years, poses other important challenges, since the efficiency of rechargeable energy sources is substantially constant, and any other evolution is based on device architecture only. How can we still increase the computational power/reduce the power consumption of our electronic environments? A first answer to this question comes from the quest for new functionalities. Within this aim, negative capacitance (NC) is becoming one of the most intriguing and studied phenomena since it can be exploited for reducing the aforementioned limiting effects in the downscaling of electronic devices. Here we report the evidence of negative capacitance in 80 nm thick ZnO thin films sputtered on Au interdigital electrodes (IDEs). Highly (002)-oriented ZnO thin films, with a fine-grained surface nanostructure and the desired chemical composition, are deposited at room temperature on different IDEs structures. Direct-current electrical measurements highlighted the semiconducting nature of ZnO (current density in the order of 1 × 10−3 A/cm2). When turned into the alternating current regime (from 20 Hz to 2 MHz) the presence of NC values is observed in the low-frequency range (20−120 Hz). The loss of metal/semiconductor interface charge states under forward bias conditions, together with the presence of oxygen vacancies and piezoelectric/electrostriction effects, is believed to be at the basis of the observed negative behavior, suggesting that ZnO thin-film-based field-effect transistors can be a powerful instrument to go beyond the Boltzmann limit and the downscaling of integrated circuit elements required for the fabrication of portable and miniaturized electronic devices, especially for electric household appliances working in the low 50 Hz utility frequency
New Perspectives on Machine Learning in Drug Discovery
No full textArtificial intelligence methods, in particular, machine learning, has been playing a pivotal role in drug development, from structural design to the clinical trial. This approach is harnessing the impact of computer-aided drug discovery due to large available data sets for drug candidates and its new and complex manner of information interpretation to identify patterns for the study scope. In the present review, recent applications related to drug discovery and therapies are assessed, and limitations and future perspectives are analyzed
Selective growth of ZnO nanowires on substrates patterned by photolithography and inkjet printing
No full textZinc oxide nanowires (ZnO NWs) were grown by a two-step growth method, involving the deposition of a patterned ZnO thin seeding layer and the chemical vapor deposition (CVD) of ZnO NWs. Two ways of patterning the seed layer were performed. The seeding solution containing ZnO precursors was deposited by sol-gel/spin coating technique and patterned by photolithography. In the other case, the seeding solution was directly printed by inkjet printing only on selected portion of the substrate areas. In both cases, crystallization of the seed layer was achieved by thermal annealing in ambient air. Vertically aligned ZnO NWs were then grown by CVD on patterned, seeded substrates. The structure and morphology of ZnO NWs was analyzed by means of X-ray diffraction and field emission scanning electron microscopy measurements, respectively, while the vibrational properties were evaluated through Raman spectroscopy. Results showed that less-defective, vertically aligned, c-axis oriented ZnO NWs were grown on substrates patterned by photolithography while more defective nanostructures were grown on printed seed layer. A feature size of 30 µm was transferred into the patterned seed layer, and a good selectivity in growing ZnO NWs was obtaine
Development of a Flexible Lead-Free Piezoelectric Transducer for Health Monitoring in the Space Environment
No full textIn this work we report on the fabrication process for the development of a flexible piezopolymeric transducer for health monitoring applications, based on lead-free, piezoelectric zinc oxide (ZnO) thin films. All the selected materials are compatible with the space environment and were deposited by the RF magnetron sputtering technique at room temperature, in view of preserving the total flexibility of the structures, which is an important requirement to guarantee coupling with cylindrical fuel tanks whose integrity we want to monitor. The overall transducer architecture was made of a c-axis-oriented ZnO thin film coupled to a pair of flexible Polyimide foils coated with gold (Au) electrodes. The fabrication process started with the deposition of the bottom electrode on Polyimide foils. The ZnO thin film and the top electrode were then deposited onto the Au/Polyimide substrates. Both the electrodes and ZnO layer were properly patterned by wet-chemical etching and optical lithography. The assembly of the final structure was then obtained by gluing the upper and lower Polyimide foils with an epoxy resin capable of guaranteeing low outgassing levels, as well as adequate thermal and electrical insulation of the transducers. The piezoelectric behavior of the prototypes was confirmed and evaluated by measuring the mechanical displacement induced from the application of an external voltage
The Pottesman Collection in the British Museum. Early Dynastic and Sargonic administrative texts. With an Appendix on a Palmyrene Inscription
No full textEdizione, trascrizione, traduzione e commento di un frammento di iscrizione palmirena inedita presente nella collezione Pottesman del British Museum (Appendice Agostini).The British Museum houses a small collection of six cuneiform tablets and a Palmyrene dedicatory inscription purchased in 1987 from the private collection of Solomon Pottesman. The aim of the present contribution is to provide a catalog of this lot and an edition of the so far unpublished cuneiform texts. In the appendix, Alessio Agostini added the edition of the Palmyrene inscription, which would have otherwise gone beyond the capabilities of the present author
Recensione di Cecilia Falchini (2023). Ruperto di deutz - Un’intima familiarità. Antologia, Edizioni Qiqajon (Comunità di Bose), Magnano (Bi), 281 pp.
No full textReview of Cecilia Falchini (2023). Ruperto di deutz - Un’intima familiarità. Antologia, Edizioni Qiqajon (Comunità di Bose), Magnano (Bi), 281 pp.
Author: Alessio MagogaRecensione di Cecilia Falchini (2023). Ruperto di deutz - Un’intima familiarità. Antologia, Edizioni Qiqajon (Comunità di Bose), Magnano (Bi), 281 pp.
Autor: Alessio Magog
Patterning dye-sensitized solar cell photoanodes through a polymeric approach: A perspective
No full textPerformances in terms of efficiency and stability of dye-sensitized solar cells (DSSCs) depend on several factors related to the preparation of the device components (electrodes and electrolyte). In particular, patterning techniques recently intruded in the third generation photovoltaic scenario with promising results. In this perspective, we introduce the most interesting strategies proposed for the patterning of photoanodes and cathodes. Afterwards, we propose a novel approach exclusively based on the use of polymeric materials. The resulting DSSC shows a power conversion efficiency equal to 5.33% measured under 1 sun irradiation, and retains the 96% of this value in a prolonged aging test (2000 h at 50 °C)
Supplemental material for What cancer patients actually know regarding medical cannabis? A cross-sectional survey with a critical analysis of the current attitudes
No full textSupplemental Material for What cancer patients actually know regarding medical cannabis? A cross-sectional survey with a critical analysis of the current attitudes by Alessio Cortellini, Giampiero Porzio, Vincenza Cofini, Stefano Necozione, Raffaele Giusti, Paolo Marchetti, Maria A Aloe Spiriti, Andrea Costanzi, Flaminia Peris, Giulio Ravoni, Giuseppe Spinelli, Corrado Ficorella and Lucilla Verna in Journal of Oncology Pharmacy Practice</p
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