35 research outputs found

    Nuclear Factor \u3baB-Dependent Neurite Remodeling Is Mediated by Notch Pathway

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    In this study, we evaluated whether a cross talk between nuclear factor \u3baB (NF-\u3baB) and Notch may take place and contribute to regulate cell morphology and/or neuronal network in primary cortical neurons. We found that lack of p50, either induced acutely by inhibiting p50 nuclear translocation or genetically in p50(-/-) mice, results in cortical neurons characterized by reduced neurite branching, loss of varicosities, and Notch1 signaling hyperactivation. The neuronal morphological effects found in p50(-/-) cortical cells were reversed after treatment with the \u3b3-secretase inhibitor DAPT (N-[N-(3,5-difluorophenacetyl)-1-alanyl 1]-S-phenylglycine t-butyl ester) or Notch RNA interference. Together, these data suggested that morphological abnormalities in p50(-/-) cortical neurons were dependent on Notch pathway hyperactivation, with Notch ligand Jagged1 being a major player in mediating such effect. In this line, we demonstrated that the p50 subunit acts as transcriptional repressor of Jagged1. We also found altered distribution of Notch1 and Jagged1 immunoreactivity in the cortex of p50(-/-) mice compared with wild-type littermates at postnatal day 1. These data suggest the relevance of future studies on the role of Notch/NF-\u3baB cross talk in regulating cortex structural plasticity in physiological and pathological conditions

    Conformational altered p53 as an early marker of oxidative stress in Alzheimer\u27s disease

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    In order to study oxidative stress in peripheral cells of Alzheimer\u27s disease (AD) patients, immortalized lymphocytes derived from two peculiar cohorts of patients, referring to early onset AD (EOSAD) and subjects harboured AD related mutation (ADmut), were used. Oxidative stress was evaluated measuring i) the typical oxidative markers, such as HNE Michel adducts, 3 Nitro-Tyrosine residues and protein carbonyl on protein extracts, ii) and the antioxidant capacity, following the enzymatic kinetic of superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione reductase (GRD). We found that the signs of oxidative stress, measured as oxidative marker levels, were evident only in ADmut but not in EOSAD patients. However, oxidative imbalance in EOSAD as well as ADmut lymphocytes was underlined by a reduced SOD activity and GRD activity in both pathological groups in comparison with cells derived from healthy subjects. Furthermore, a redox modulated p53 protein was found conformational altered in both EOSAD and ADmut B lymphocytes in comparison with control cells. This conformational altered p53 isoform, named unfolded p53 , was recognized by the use of two specific conformational anti-p53 antibodies. Immunoprecipitation experiments, performed with the monoclonal antibodies PAb1620 (that recognizes p53wt) and PAb240 (that is direct towards unfolded p53), and followed by the immunoblotting with anti-4-hydroxynonenal (HNE) and anti- 3-nitrotyrosine (3NT) antibodies, showed a preferential increase of nitrated tyrosine residues in unfolded p53 isoform comparing to p53 wt protein, in both ADmut and EOSAD. In addition, a correlation between unfolded p53 and SOD activity was further found. Thus this study suggests that ROS/RNS contributed to change of p53 tertiary structure and that unfolded p53 can be considered as an early marker of oxidative imbalance in these patients

    Ultrafast Excited-State Localization in Cs2AgBiBr6 Double Perovskite

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    Cs2AgBiBr6 is a promising metal halide double perovskite offering the possibility of efficient photovoltaic devices based on lead-free materials. Here, we report on the evolution of photoexcited charge carriers in Cs2AgBiBr6 using a combination of temperature-dependent photoluminescence, absorption and optical pump–terahertz probe spectroscopy. We observe rapid decays in terahertz photoconductivity transients that reveal an ultrafast, barrier-free localization of free carriers on the time scale of 1.0 ps to an intrinsic small polaronic state. While the initially photogenerated delocalized charge carriers show bandlike transport, the self-trapped, small polaronic state exhibits temperature-activated mobilities, allowing the mobilities of both to still exceed 1 cm2 V–1 s–1 at room temperature. Self-trapped charge carriers subsequently diffuse to color centers, causing broad emission that is strongly red-shifted from a direct band edge whose band gap and associated exciton binding energy shrink with increasing temperature in a correlated manner. Overall, our observations suggest that strong electron–phonon coupling in this material induces rapid charge-carrier localization

    The role of de-excitation in the final-state interactions of protons in neutrino-nucleus interactions

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    Present and next generation of long-baseline accelerator experiments are bringing the measurement of neutrino oscillations into the precision era with ever-increasing statistics. One of the most challenging aspects of achieving such measurements is developing relevant systematic uncertainties in the modeling of nuclear effects in neutrino-nucleus interactions. To address this problem, state-of-the-art detectors are being developed to extract detailed information about all particles produced in neutrino interactions. To fully profit from these experimental advancements, it is essential to have reliable models of propagation of the outgoing hadrons through nuclear matter able to predict how the energy is distributed between all the final-state observed particles. In this article, we investigate the role of nuclear de-excitation in neutrino-nucleus scattering using two Monte Carlo cascade models: NuWro and INCL coupled with the de-excitation code ABLA. The ablation model ABLA is used here for the first time to model de-excitation in neutrino interactions. As input to ABLA, we develop a consistent simulation of nuclear excitation energy tuned to electron-scattering data. The paper includes the characterization of the leading proton kinematics and of the nuclear cluster production during cascade and de-excitation. The observability of nuclear clusters as vertex activity and their role in a precise neutrino energy reconstruction is quantified.Comment: 14 pages, 13 figure

    Charge-Carrier Mobility and Localization in Semiconducting Cu2AgBiI6 for Photovoltaic Applications

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    Lead-free silver–bismuth semiconductors have become increasingly popular materials for optoelectronic applications, building upon the success of lead halide perovskites. In these materials, charge-lattice couplings fundamentally determine charge transport, critically affecting device performance. In this study, we investigate the optoelectronic properties of the recently discovered lead-free semiconductor Cu2AgBiI6 using temperature-dependent photoluminescence, absorption, and optical-pump terahertz-probe spectroscopy. We report ultrafast charge-carrier localization effects, evident from sharp THz photoconductivity decays occurring within a few picoseconds after excitation and a rise in intensity with decreasing temperature of long-lived, highly Stokes-shifted photoluminescence. We conclude that charge carriers in Cu2AgBiI6 are subject to strong charge-lattice coupling. However, such small polarons still exhibit mobilities in excess of 1 cm2 V–1 s–1 at room temperature because of low energetic barriers to formation and transport. Together with a low exciton binding energy of ∼29 meV and a direct band gap near 2.1 eV, these findings highlight Cu2AgBiI6 as an attractive lead-free material for photovoltaic applications

    Monitoring and predicting the risk of violence in residential facilities. No difference between patients with history or with no history of violence

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    none34noopende Girolamo, Giovanni; Buizza, Chiara; Sisti, Davide; Ferrari, Clarissa; Bulgari, Viola; Iozzino, Laura; Boero, Maria Elena; Cristiano, Giuseppe; De Francesco, Alessandra; Giobbio, Gian Marco; Maggi, Paolo; Rossi, Giuseppe; Segalini, Beatrice; Candini, Valentina; Andreose, Suor; Basso, Pasquale; Beneduce, Rossella; Bertolotti, Pietro; Braida, Vanda; Bonelli, Marina; Bongiorno, Fanny; Bussi, Riccardo; Castagno, Elisa; Dominicis, Fabio; Ghersi, Loredana; Greppo, Stefania; Sodano, Alessandro Jaretti; Leporatti, Massimo; Presti, Eleonora Lo; Milone, Valeria; Panigada, Fausto; Pasquadibisceglie, Livia; Rigamonti, Danilo; Rillosi, Lucianade Girolamo, Giovanni; Buizza, Chiara; Sisti, Davide; Ferrari, Clarissa; Bulgari, Viola; Iozzino, Laura; Boero, Maria Elena; Cristiano, Giuseppe; De Francesco, Alessandra; Giobbio, Gian Marco; Maggi, Paolo; Rossi, Giuseppe; Segalini, Beatrice; Candini, Valentina; Andreose, Suor; Basso, Pasquale; Beneduce, Rossella; Bertolotti, Pietro; Braida, Vanda; Bonelli, Marina; Bongiorno, Fanny; Bussi, Riccardo; Castagno, Elisa; Dominicis, Fabio; Ghersi, Loredana; Greppo, Stefania; Sodano, Alessandro Jaretti; Leporatti, Massimo; Presti, Eleonora Lo; Milone, Valeria; Panigada, Fausto; Pasquadibisceglie, Livia; Rigamonti, Danilo; Rillosi, Lucian

    Conformational Altered p53 as an Early Marker of Oxidative Stress in Alzheimer's Disease

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    In order to study oxidative stress in peripheral cells of Alzheimer's disease (AD) patients, immortalized lymphocytes derived from two peculiar cohorts of patients, referring to early onset AD (EOSAD) and subjects harboured AD related mutation (ADmut), were used. Oxidative stress was evaluated measuring i) the typical oxidative markers, such as HNE Michel adducts, 3 Nitro-Tyrosine residues and protein carbonyl on protein extracts, ii) and the antioxidant capacity, following the enzymatic kinetic of superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione reductase (GRD). We found that the signs of oxidative stress, measured as oxidative marker levels, were evident only in ADmut but not in EOSAD patients. However, oxidative imbalance in EOSAD as well as ADmut lymphocytes was underlined by a reduced SOD activity and GRD activity in both pathological groups in comparison with cells derived from healthy subjects. Furthermore, a redox modulated p53 protein was found conformational altered in both EOSAD and ADmut B lymphocytes in comparison with control cells. This conformational altered p53 isoform, named “unfolded p53”, was recognized by the use of two specific conformational anti-p53 antibodies. Immunoprecipitation experiments, performed with the monoclonal antibodies PAb1620 (that recognizes p53wt) and PAb240 (that is direct towards unfolded p53), and followed by the immunoblotting with anti-4-hydroxynonenal (HNE) and anti- 3-nitrotyrosine (3NT) antibodies, showed a preferential increase of nitrated tyrosine residues in unfolded p53 isoform comparing to p53 wt protein, in both ADmut and EOSAD. In addition, a correlation between unfolded p53 and SOD activity was further found. Thus this study suggests that ROS/RNS contributed to change of p53 tertiary structure and that unfolded p53 can be considered as an early marker of oxidative imbalance in these patients

    Is the caloric stimulation of the vestibule hydrostatic or hydrodynamic in nature?

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    Results of experiments in which isolated frog labyrinth preparation was locally heated were consistent with the predictions of the so-called hydrostatic model of the canal (Gentine et al., 1991) and not with those of models assuming convective endolymphatic currents

    Communication and interpersonal skills in medicine: an educational intervention in hospital

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    The present paper is aimed to describe methods and results of an educational intervention on doctor-patient communication. The intervention was addressed to 26 hospital physicians and lasted 20 hours, and it was formulated according to patient-centred model. At the end of the intervention, participants referred satisfaction for the course, and the proportion of doctors with patient-centred style was higher compared to the one of the initial assessment (Z Wilcoxon=2,236; p=.02). No associations were found between communicative-relational style and sociodemographic variables. For hospital physicians, three main topics seems require future interventions: the communication of bad news, the management of own emotions, the influence of context's factors on doctor-patient relationship

    Simulation of cupulolithiasis and canalolithiasis by an animal model

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    The physical mechanisms responsible for cupulolithiasis and canalolithiasis have been investigated by two groups of experiments in isolated posterior semicircular canal (SCC) of frog (Rana esculenta L.). First, clouds of 10-30 isolated otoconia were let to fall (snowfall of otoconia) either through the ampulla onto the cupula, or inside the long arm of the canal, opposite to the cupula. Second, microspheres ranging 30 to 350 µm in diameter were gently moved to and fro inside the long arm of the canal by a micromanipulator. The effects were evaluated by recording the firing rate (Nfr) of the ampullary nerve. Snowfall of otoconia produced detectable changes of Nfr only when otoconia got in contact with the cupula, but not when falling through the endolymph. Movement of the microspheres in the canal long arm induced Nfr changes only if the microsphere diameter exceeded about 50 µm. Although the exact microsphere size needed for receptor stimulation may depend on the experimental conditions, these results strongly suggest that debris moving inside a SCC (canalolithiasis) can produce transcupular pressures able to stimulate ampullar receptors only if they have suitable size, whereas isolated otoconia cannot, except when lying on the cupula (cupulolithiasis). Difference of the mechanisms acting during canalo- and cupulo-lithiasis is discussed
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