Exploring the Betrothed Lovers

We present the ongoing activities and the first results achieved in a research project concerning the understanding of narrative in the high school. Students and teachers experimented with new ways to learn linguistic and digital skills, by using a collaborative learning environment built around the novel I Promessi Sposi. We analyzed the literary text, extracting social networks of characters and other fundamental narrative elements (sequences, locations, etc.), in order to provide the students with appropriate tools and resources to conduct their own inquiries on the novel

Lip Metastasis: An Overview of the Last 30 Years

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Hepatic manifestations of drug reaction with eosinophilia and systemic symptoms syndrome

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a potentially life-threatening drug reaction, which can affect multiple organs. Patients with DRESS syndrome and hepatic manifestations may present alterations ranging from mild hepatitis to acute liver failure. The diagnosis might be difficult, and the management of these patients is challenging. This report analyzes a series of five cases reporting the clinical presentation, which ranged from acute hepatitis to liver failure, and discussed their treatment

Analysis of a Flexible Dual-Channel Octagonal Coil System for UHF MRI

Nowadays, MRI is focused on using ultra-high static magnetic fields (> 7 T) to increase the signal-to-noise ratio. The use of high fields, on the other hand, requires novel technical solutions as well as more stringent design criteria for specific absorption rate levels, reducing radiative effect and coil resistance. In this paper, two flexible RF coils for 7 T human magnetic resonance, and 298 MHz ultra-high frequency operations were analyzed and characterized. Imaging of lower human limbs is regarded as a case study. The lumped element theory and subsequent numerical simulations were used to fine-tune the single-coil element and the dual-coil array design, respectively. Here, we demonstrate how the shape, size, configuration, and presence of the sample influence the coil performance. The penetration depth of the B 1 -field and the specific absorption rate values have been determined numerically using two numerical surface phantoms: saline and a multilayer human tissue. A preliminary study in the presence of a saline solution phantom has been carried out to develop and validate the dual-coil system. The frequency response of the dual-coil array was measured to assess its robustness when coupled to twelve human volunteers. We found that our design is robust to variations in the anatomical properties of the human thighs, and hence to coil bending. The presented approach can be useful for the implementation of flexible devices with high sensitivity levels and low specific absorption rat

Structural and Functional Characterization of a New Double Variant Haemoglobin (HbG-Philadelphia/Duarte α268Asn→Lysβ262Ala→Pro)

We report the first case of cosegregation of two haemoglobins (Hbs): HbG-Philadelphia [α68(E17)Asn → Lys] and HbDuarte [β62(E6)Ala → Pro]. The proband is a young patient heterozygous also for β°-thalassaemia. We detected exclusively two haemoglobin variants: HbDuarte and HbG-Philadelphia/Duarte. Functional study of the new double variant HbG-Philadelphia/Duarte exhibited an increase in oxygen affinity, with a slight decrease of cooperativity and Bohr effect. This functional behaviour is attributed to β62Ala → Pro instead of α68Asn → Lys substitution. Indeed, HbG-Philadelphia isolated in our laboratory from blood cells donor carrier for this variant is not affected by any functional modification, whereas purified Hb Duarte showed functional properties very similar to the double variant. NMR and MD simulation studies confirmed that the presence of Pro instead of Ala at the β62 position produces displacement of the E helix and modifications of the tertiary structure. The substitution α68(E17)Asn → Lys does not cause significant structural and dynamical modifications of the protein. A possible structure-based rational of substitution effects is suggested

A Reconfigurable Inductor Based on Vanadium Dioxide Insulator-to-Metal Transition

This letter introduces a reconfigurable planar square-coil-shaped inductor exploiting as the tuning mechanism the insulator-to-metal transition (IMT) of a vanadium dioxide (VO2) switch placed in the interwinding space in an unprecedented manner. The VO2 thin-film bar-shaped switch is electrically connected to provide a temperature-selective current path that effectively short-circuits a part of the inductor coil changing the inductance of the device. The inductor is fabricated on a high-resistivity silicon substrate using a CMOS-compatible 2-D planar low-cost technology (four photolithography steps). The design, optimized to work in the 4-10-GHz range, provides measured inductances at 5 GHz of 2.1 nH at 20 degrees C and 1.35 nH at 100 degrees C with good stability in the entire frequency band (4-10 GHz) resulting in a reconfiguration ratio of 55%. The quality factor (Q-factor) at 7 GHz is about 8 at 20 degrees C (off state) and 3 at 100 degrees C (on state), outperforming tunable inductors employing VO2 with 2 orders of magnitude higher Q-factor and a smaller footprint. This represents an advancement for the state of the art of 2-D CMOS-compatible inductors in the considered frequency range

The Complex Story Behind a Deep Eutectic Solvent Formation as Revealed by L‑Menthol Mixtures with Butylated Hydroxytoluene Derivatives.

An in-depth study of the hydrophobic eutectic mixtures formed by L-menthol (MEN) with the butylated hydroxytoluene (BHT), 2-tert-butyl-pcresol (TBC), and p-cresol (PC) compounds has been carried out, where TBC and PC are analogous to the BHT species but with a different degree of steric hindrance around the hydroxyl group. Thermal characterization evidenced that the BHT/MEN system can be classified as an ideal eutectic, while the TBC/MEN and PC/MEN mixtures behave as type V deep eutectic solvents (DESs) for a wide range of compositions around the eutectic point. As shown by an array of experimental and theoretical methods, in the BHT/MEN mixtures the establishment of hydrogen-bond (H-bond) interactions between the components is dramatically hampered because of the steric hindrance in the BHT molecule, so that the achievement of a liquid phase at room temperature for the eutectic composition is driven by apolar−apolar attractions among the alkyl functional groups of the constituents. Differently, the TBC-MEN donor−receptor H-bond is the main driving force for the formation of a type V DES and derives from a concurrence of electronic and steric factors characterizing the TBC molecule. Finally, the absence of steric hindrance around the hydroxyl group allows the self-association among PC molecules through H-bonded networks already in the pristine compound, but the replacement with the more favorable PC-MEN H-bond provides a type V DES upon mixing of these components. Our combined approach, together with the peculiarity of the inspected systems, delivered an archetypal study able to shed light onto the various contributions ruling the structure− properties relationship in DESs and possibly deepening the currently accepted view of these inherently complex media

Defects in III-N LEDs: experimental identification and impact on electro-optical characteristics

III-N light-emitting-diodes (LEDs) are subject of intense investigations, thanks to their high efficiency and great reliability. The quality of the semiconductor material has a significant impact on the electro-optical performance of LEDs: for this reason, a detailed characterization of defect properties and the modeling of the impact of defects on device performance are of fundamental importance. This presentation addresses this issue, by discussing a set of recent case studies on the topic; specifically, we focus on the experimental characterization of defects, and on the modeling of their impact on the electro-optical characteristics of the devices

Tunable RF phase shifters based on Vanadium Dioxide metal insulator transition

This paper presents the design, fabrication, and electrical characterization of a reconfigurable RF capacitive shunt switch that exploits the electro-thermally triggered vanadium dioxide (VO2) insulator to metal phase transition. The RF switch is further exploited to build wide-band RF true-time delay tunable phase shifters. By triggering the VO2 switch insulator to metal transition (IMT), the total capacitance can be reconfigured from the series of two metal-insulator-metal (MIM) capacitors to a single MIM capacitor. The effect of bias voltage on losses and phase shift is investigated, explained, and compared to the state of the art in the field. We report thermal actuation of the devices by heating the devices above VO2 IMT temperature. By cascading multiple stages a maximum of 40° per dB loss close to 7 GHz were obtained