1,759 research outputs found

    Per il «Doligamus» di Adolfo di Vienna: le “fabulae” VIII e IX, ovvero alcune variazioni sul tema

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    Il «Doligamus», opera latina in 342 distici elegiaci e 7 esametri leonini degli inizi del sec. XIV (1315), si inserisce pienamente nel filone di poesia misogina di origine clericale che ebbe grande diffusione durante il Medioevo. Il suo autore, Adolfo di Vienna, attinge alla tradizione degli "exempla" e del materiale favolistico per condannare, in nove "fabulae", il comportamento deplorevole delle donne, siano esse mogli infedeli o vecchie diaboliche. In questo lavoro, dopo una presentazione generale dell’autore e dell’opera, ci si sofferma sulle ultime due "fabulae" del «Doligamus», la VIII e la IX, delle quali vengono studiati e analizzati la trama, i modelli, lo stile, la lingua e, soprattutto, le diverse “variazioni sul tema” nell’ambito della produzione novellistica ed esemplare dei secc. XIII e XIV.The «Doligamus», a latin work of 342 elegiac couplets and 7 leonine hexameters of the beginnings of XIVth century (1315), is strictly inserted in the misogynous clerical poetry which had a big diffusion during the Middle Ages. His author, Adolph of Vienna, draws from the tradition of "exempla" and "fabulae" for condemning, in his nine "fabulae", the dreadful manners of women, adulterous wives or diabolic old females. This paper, after a general presentation on the author and the work, offers an analysis of the lost two "fabulae" of the «Doligamus» (fab. VIIIth and IXth), in his plot, sources, style, language and, expecially, in the several “variations on the theme” in the literary production of short stories and "exempla" between XIIIth and XIVth centuries

    Simulation of a trust and reputation based mitigation protocol for a black hole style attack on VANETs

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    From a security standpoint, VANETs (Vehicular ad hoc Networks) are vulnerable to attacks by malicious users, due to the decentralized and open nature of the wireless system. For many of these kinds of attacks detection is unfeasible, thus making it hard to produce security. Despite their characterization as dynamically reconfigurable networks, it is nonetheless essential to identify topology and population properties that can optimise mitigation protocols’ deployment. In this paper, we provide an algorithmic definition and simulation of a trust and mitigation based protocol to contain a Black Hole style attack on a VANET. We experimentally show its optimal working conditions: total connectivity, followed by a random network; connection to external networks; early deployment of the protocol and ranking of the message. We compare results with those of existing protocols and future work shall focus on repeated broadcasting, opportunistic message forwarding and testing on real data

    Egg parasitoid exploitation of plant volatiles induced by single or concurrent attack of a zoophytophagous predator and an invasive phytophagous pest

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    Zoophytophagous insect predators can induce physiological responses in plants by activating defence signalling pathways, but whether plants can respond to facultative phytophagy by recruiting natural enemies remains to be investigated. In Y-tube olfactometer bioassays, using a system including a Vicia faba plant, the zoophytophagous predator Podisus maculiventris and the egg parasitoid Telenomus podisi, we first demonstrated that T. podisi females are attracted by broad bean plants damaged by feeding activity of P. maculiventris and on which host egg masses had been laid, while they are not attracted by undamaged plants or plants damaged by feeding activity alone. In a second experiment, we evaluated the impact of the invasive phytophagous pest Halyomorpha halys on this plant volatile-mediated tritrophic communication. Results showed that the invasive herbivorous adults do not induce plants to recruit the native egg parasitoid, but they can disrupt the local infochemical network. In fact, T. podisi females are not attracted by volatiles emitted by plants damaged by H. halys feeding alone or combined with oviposition activity, nor are they attracted by plants concurrently infested by P. maculiventris and H. halys, indicating the specificity in the parasitoid response and the ability of the invasive herbivore in interrupting the semiochemical communication between plants and native egg parasitoids. To the best of our knowledge, this is the first study showing that zoophytophagous predator attacks induce indirect plant defences similarly to those defence strategies adopted by plants as a consequence of single or concurrent infestations of herbivorous insects

    Quinoline-based molecules targeting c-Met, EGF, and VEGF receptors and the proteins involved in related carcinogenic pathways

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    The quinoline ring system has long been known as a versatile nucleus in the design and synthesis of biologically active compounds. Currently, more than one hundred quinoline compounds have been approved in therapy as antimicrobial, local anaesthetic, antipsychotic, and anticancer drugs. In drug discovery, indeed, over the last few years, an increase in the publication of papers and patents about quinoline derivatives possessing antiproliferative properties has been observed. This trend can be justified by the versatility and accessibility of the quinoline scaffold, from which new derivatives can be easily designed and synthesized. Within the numerous quinoline small molecules developed as antiproliferative drugs, this review is focused on compounds effective on c-Met, VEGF (vascular endothelial growth factor), and EGF (epidermal growth factor) receptors, pivotal targets for the activation of important carcinogenic pathways (Ras/Raf/MEK and PI3K/AkT/mTOR). These signalling cascades are closely connected and regulate the survival processes in the cell, such as proliferation, apoptosis, differentiation, and angiogenesis. The antiproliferative biological data of remarkable quinoline compounds have been analysed, confirming the pivotal importance of this ring system in the efficacy of several approved drugs. Furthermore, in view of an SAR (structure-activity relationship) study, the most recurrent ligand–protein interactions of the reviewed molecules are summarized

    TTF-1/p63-positive poorly differentiated NSCLC: A histogenetic hypothesis from the basal reserve cell of the terminal respiratory unit

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    TTF-1 is expressed in the alveolar epithelium and in the basal cells of distal terminal bronchioles. It is considered the most sensitive and specific marker to define the adenocarcinoma arising from the terminal respiratory unit (TRU). TTF-1, CK7, CK5/6, p63 and p40 are useful for typifying the majority of non-small-cell lung cancers, with TTF and CK7 being typically expressed in adenocarcinomas and the latter three being expressed in squamous cell carcinoma. As tumors with coexpression of both TTF-1 and p63 in the same cells are rare, we describe different cases that coexpress them, suggesting a histogenetic hypothesis of their origin. We report 10 cases of poorly differentiated non-small-cell lung carcinoma (PD-NSCLC). Immunohistochemistry was performed by using TTF-1, p63, p40 (∆Np63), CK5/6 and CK7. EGFR and BRAF gene mutational analysis was performed by using real-time PCR. All the cases showed coexpression of p63 and TTF-1. Six of them showing CK7+ and CK5/6− immunostaining were diagnosed as “TTF-1+ p63+ adenocarcinoma”. The other cases of PD-NSCLC, despite the positivity for CK5/6, were diagnosed as “adenocarcinoma, solid variant”, in keeping with the presence of TTF-1 expression and p40 negativity. A “wild type” genotype of EGFR was evidenced in all cases. TTF1 stained positively the alveolar epithelium and the basal reserve cells of TRU, with the latter also being positive for p63. The coexpression of p63 and TTF-1 could suggest the origin from the basal reserve cells of TRU and represent the capability to differentiate towards different histogenetic lines. More aggressive clinical and morphological features could characterize these “basal-type tumors” like those in the better known “basal-like” cancer of the breast

    Off-target-based design of selective hiv-1 protease inhibitors

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    The approval of the first HIV-1 protease inhibitors (HIV-1 PRIs) marked a fundamental step in the control of AIDS, and this class of agents still represents the mainstay therapy for this illness. Despite the undisputed benefits, the necessary lifelong treatment led to numerous severe side-effects (metabolic syndrome, hepatotoxicity, diabetes, etc.). The HIV-1 PRIs are capable of interacting with “secondary” targets (off-targets) characterized by different biological activities from that of HIV-1 protease. In this scenario, the in-silico techniques undoubtedly contributed to the design of new small molecules with well-fitting selectivity against the main target, analyzing possible undesirable interactions that are already in the early stages of the research process. The present work is focused on a new mixed-hierarchical, ligand-structure-based protocol, which is centered on an on/off-target approach, to identify the new selective inhibitors of HIV-1 PR. The use of the well-established, ligand-based tools available in the DRUDIT web platform, in combination with a conventional, structure-based molecular docking process, permitted to fast screen a large database of active molecules and to select a set of structure with optimal on/off-target profiles. Therefore, the method exposed herein, could represent a reliable help in the research of new selective targeted small molecules, permitting to design new agents without undesirable interactions

    Dopants and defects in proton-conducting perovskites

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    Many doped perovskites show high proton conductivity at intermediate to high temperatures (500- 900 °C), which has opened possibilities for many prospected applications in energy conversion (fuel cells), and electrochemical devices. In a doped perovskite, e.g. BaCe1-xYxO3-y, oxygen vacancies are created by charge compensation, and can eventually react with air moisture to form structural protonic defects. The sluggish nature of the proton, which is practically invisible to most structural analyses, and poses enormous problems to quantum chemistry, has surely contributed to slow down the progress in the understanding of these materials: in fact, the conduction dynamics and its interplay with structure are still matter of debate. The kind of trivalent dopant and its size, and the doping level, have all been found to critically influence the conductivity: to date, however, no comprehensive model was developed, and no clear explanations exist between the chemical and dynamical properties. Here we present results collected in several EXAFS experiments on doped BaCeO3 and BaZrO3 spanning three years, on the Ba site, Ce site, and the dopant (yttrium, gadolinium, indium: the ionic sizes of these are respectively equal, larger and smaller than Ce4+) site. The local structures up to about 6 Å around each site are solved with state-of-the-art techniques employing both the GNXAS and FEFF approaches, revealing unique features and demonstrating that in this case the conventional diffraction techniques are not suited to unravel the complexity of doped crystals. In particular, the attention will be drawn on the local deviations from Vegard’s law, the local expansion/contraction as a function of hydration degree, the interplay between dopant and defects, and the chemical compatibility (Pearson absolute hardness) instead of ionic size matching. The EXAFS results are correlated with complementary information about the dynamics of protons and other defects (IR and neutron vibrational spectroscopy, QENS, ionic and electronic conductivity measurements)

    Microcephaly and macrocephaly. A study on anthropometric and clinical data from 308 subjects

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    Head circumference is the auxological parameter that most correlates with developmental anomalies in childhood. Head circumference (HC) two standard deviations (SD) below or above the mean defines microcephaly and macrocephaly, respectively. The aim of this retrospective study was to explore anthropometric parameters and clinical characteristics among subjects with abnormalities in HC who had been referred for developmental assessment. One hundred and sixty four subjects with microcephaly and 144 subjects with macrocephaly were enrolled from birth to 18 months of age. Head circumference at birth and the association with variables related to maternal health status, gestational age, growth pattern, brain imaging and clinical characteristics were analyzed. In some cases, an etiological diagnosis was made. In the two considered conditions, we found different anthropometric and clinical associations, some of which were statistically significant, with implications for ongoing neurodevelopmental surveillance

    Indium doping of proton-conducting solid oxides

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    Solid oxides protonic conductors are prepared by doping the pure matrix compounds with cationic species. Barium cerate and barium zirconate are perovskite-like compounds, characterized by a network of corner-sharing MeO6 octahedra (Me=Ce, Zr). Barium lies in the cavities between octahedra. Insertion of trivalent species in the octahedral site involves the formation of charge- compensating oxygen vacancies, that can be filled by hydroxyls coming from dissociative water absorption. Then, proton delocalization among structural oxygens ensures conductivity. The most effective conductors are obtained by yttrium doping that, on the other hand, enters only in limited amounts in both BaZrO3 and BaCeO3, thus involving limited carrier concentration. Perovskites are affected by different drawbacks: barium cerate compounds are very sensitive to the acidic components present in the environment and in particular to CO2 that induces decomposition in barium carbonate and cerium oxide; barium zirconate, notwithstanding a very high bulk conductivity, is biased by high grain boundary resistivity. A possible alternative to perovskite-like compounds is constituted by fergusonite-type lanthanum niobate and lanthanum tantalate compounds, characterized by a tetrahedral coordination of Nb and Ta. These oxides present a very high chemical stability but very low carrier concentration, usually induced by Ca-doping the lanthanum site [1]. Among the different trivalent dopants, it was demonstrated by X-ray absorption spectroscopy that indium is able to enter in any composition in the perovskite network, thus providing a very high carrier concentration, even if with lower proton mobility. This property of indium was ascribed to its electronic structure and in particular to the low Pearson hardness, allowing this cation to fit in a hosting matrix with the least structural strain [2]. A preliminar attempt of exploiting indium for enhancing the carrier concentration of lanthanum niobate was carried out. The solid state synthesis involved amounts of the reactant simple oxides suitable to force indium doping of the niobium site. X-ray diffraction do not show significant amounts of secondary oxide phases
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