169 research outputs found

    Reduced Two-Level Approach for Air Kinetics in Recombination Regime

    Get PDF
    Abstract. The possibility of using reduced model, that account for non-Boltzmann vibrational distributions for nitrogen monoxide kinetics has been explored. The basic idea is that the rate coefficients, which are proportional to the tail of the vibrational distribution function, are strictly correlated to reactant density rather than to vibrational temperature, which depend on the low energy distribution. The model consider the rate coefficients as a function of the population of the last vibrational level of the relevant species, which evolution is calculated with a proper kinetic equation

    The 236U neutron capture cross-section measured at the n-TOF CERN facility

    Get PDF
    The 236U isotope plays an important role in nuclear systems, both for future and currently operating ones. The actual knowledge of the capture reaction of this isotope is satisfactory in the thermal region, but it is considered insufficient for Fast Reactor and ADS applications. For this reason the 236U(n, γ) reaction crosssection has been measured for the first time in the whole energy region from thermal energy up to 1 MeV at the n TOF facility with two different detection systems: an array of C6D6 detectors, employing the total energy deposited method, and a 4π total absorption calorimeter (TAC), made of 40 BaF2 crystals. The two n TOF data sets agree with each other within the statistical uncertainty in the Resolved Resonance Region up to 800 eV, while sizable differences (up to 20%) are found relative to the current evaluated data libraries. Moreover two new resonances have been found in the n TOF data. In the Unresolved Resonance Region up to 200 keV, the n TOF results show a reasonable agreement with previous measurements and evaluated data

    Systemic Immune Responses in Alzheimer’s Disease: In Vitro Mononuclear Cell Activation and Cytokine Production

    Get PDF
    To investigate the systemic signs of immune-inflammatory responses in Alzheimer’s disease (AD), in the present study we have analyzed blood lymphocyte subsets and the expression of activation markers on peripheral blood mononuclear cells (PBMCs) fromADpatients and age-matched healthy controls (HC) activated in vitro by recombinant amyloid-β peptide (rAβ42). Our study of AD lymphocyte subpopulations confirms the already described decrease of the absolute number and percentage of B cells when compared to HC lymphocytes, whereas the other subsets are not significantly different in patients and controls. We report the increased expression of the activation marker CD69 and of the chemokine receptors CCR2 and CCR5 on T cells but no changes of CD25 after activation. B cells are also activated by rAβ42 as demonstrated by the enhanced expression of CCR5. Moreover, rAβ42 induces an increased expression of the scavenger receptor CD36 on monocytes. Some activation markers and chemokine receptors are overexpressed in unstimulated AD cells when compared to controls. This is evidence of the pro-inflammatory status of AD. Stimulation by rAβ42 also induces the production of the pro-inflammatory cytokines IL-1β, IL-6, IFN-γ, and TNF-α, and of the anti-inflammatory cytokines IL-10 and IL-1Ra. The chemokines RANTES, MIP-1β, and eotaxin as well as some growth factors (GM-CSF, G-CSF) are also overproduced by AD-derived PBMC activated by rAβ42. These results support the involvement of systemic immunity in AD patients. However, our study is an observational one so we cannot draw a conclusion about its contribution to the pathophysiology of the disease

    High accuracy, high resolution 235U(n,f) cross section from n_TOF (CERN) from 18 meV to 10 keV

    Get PDF
    he version of record os available online at: http://dx.doi.org/10.1140/epja/s10050-022-00779-7U(n,f) cross section was measured in a wide energy range (18 meV–170 keV) at the n_TOF facility at CERN, relative to 6Li(n,t) and 10B(n,a) standard reactions, with high resolution and accuracy, with a setup based on a stack of six samples and six silicon detectors placed in the neutron beam. In this paper we report on the results in the region between 18 meV and 10 keV neutron energy. A resonance analysis has been performed up to 200 eV, with the code SAMMY. The resulting fission kernels are compared with the ones extracted on the basis of the resonance parameters of the most recent major evaluated data libraries. A comparison of the n_TOF data with the evaluated cross sections is also performed from thermal to 10 keV neutron energy for the energy-averaged cross section in energy groups of suitably chosen width. A good agreement, within 0.5%, is found on average between the new results and the latest evaluated data files ENDF/B-VIII.0 and JEFF-3.3, as well as with respect to the broad group average fission cross section established in the framework of the standard working group of IAEA (the so-called reference file). However, some discrepancies, of up to 4%, are still present in some specific energy regions. The new dataset here presented, characterized by a unique combination of high resolution and accuracy, low background and wide energy range, can help to improve the evaluations from the Resolved Resonance Region up to 10 keV, also reducing the uncertainties that affect this region.Peer ReviewedAquest article està escrit per 130 autors/autores: Simone Amaducci, Nicola Colonna, Luigi Cosentino, Sergio Cristallo, Paolo Finocchiaro, Milan Krtiˇcka, Cristian Massimi, Mario Mastromarco, Annamaria Mazzone, Alberto Mengoni, Stanislav Valenta, Oliver Aberle, Victor Alcayne, Józef Andrzejewski, Laurent Audouin, Victor Babiano-Suarez, Michael Bacak, Massimo Barbagallo, Samuel Bennett, Eric Berthoumieux, Jon Billowes, Damir Bosnar, Adam Brown, Maurizio Busso, Manuel Caamaño, Luis Caballero-Ontanaya, Francisco Calviño, Marco Calviani, Daniel Cano-Ott, Adria Casanovas, Francesco Cerutti, Enrico Chiaveri, Guillem Cortés, Miguel Cortés-Giraldo, Lucia-Anna Damone, Paul-John Davies, Maria Diakaki, Mirco Dietz, Cesar Domingo-Pardo, Rugard Dressler, Quentin Ducasse, Emmeric Dupont, Ignacio Durán, Zinovia Eleme, Beatriz Fernández-Domínguez, Alfredo Ferrari, Valter Furman, Kathrin Göbel, Ruchi Garg, Aleksandra Gawlik, Simone Gilardoni, Isabel Gonçalves, Enrique González-Romero, Carlos Guerrero, Frank Gunsing, Hideo Harada, Stephan Heinitz, Jan Heyse, David Jenkins, Arnd Junghans, Franz Käppeler, Yacine Kadi, Atsushi Kimura, Ingrid Knapova, Michael Kokkoris, Yuri Kopatch, Deniz Kurtulgil, Ion Ladarescu, Claudia Lederer-Woods, Helmut Leeb, Jorge Lerendegui-Marco, Sarah-Jane Lonsdale, Daniela Macina, Alice Manna, Trinitario Martínez, Alessandro Masi, Pierfrancesco Mastinu, Emilio-Andrea Maugeri, Emilio Mendoza, Veatriki Michalopoulou, Paolo Milazzo, Federica Mingrone, Javier Moreno-Soto, Agatino Musumarra, Alexandru Negret, Francisco Ogállar, Andreea Oprea, Nikolas Patronis, Andreas Pavlik, Jarosław Perkowski, Luciano Piersanti, Cristina Petrone, Elisa Pirovano, Ignacio Porras, Javier Praena, José-Manuel Quesada, Diego Ramos-Doval, Thomas Rauscher, René Reifarth, Dimitri Rochman, Carlo Rubbia, Marta Sabaté-Gilarte, Alok Saxena, Peter Schillebeeckx, DorotheaPostprint (published version

    Genetics of VEGF Serum Variation in Human Isolated Populations of Cilento: Importance of VEGF Polymorphisms

    Get PDF
    Vascular Endothelial Growth Factor (VEGF) is the main player in angiogenesis. Because of its crucial role in this process, the study of the genetic factors controlling VEGF variability may be of particular interest for many angiogenesis-associated diseases. Although some polymorphisms in the VEGF gene have been associated with a susceptibility to several disorders, no genome-wide search on VEGF serum levels has been reported so far. We carried out a genome-wide linkage analysis in three isolated populations and we detected a strong linkage between VEGF serum levels and the 6p21.1 VEGF region in all samples. A new locus on chromosome 3p26.3 significantly linked to VEGF serum levels was also detected in a combined population sample. A sequencing of the gene followed by an association study identified three common single nucleotide polymorphisms (SNPs) influencing VEGF serum levels in one population (Campora), two already reported in the literature (rs3025039, rs25648) and one new signal (rs3025020). A fourth SNP (rs41282644) was found to affect VEGF serum levels in another population (Cardile). All the identified SNPs contribute to the related population linkages (35% of the linkage explained in Campora and 15% in Cardile). Interestingly, none of the SNPs influencing VEGF serum levels in one population was found to be associated in the two other populations. These results allow us to exclude the hypothesis that the common variants located in the exons, intron-exon junctions, promoter and regulative regions of the VEGF gene may have a causal effect on the VEGF variation. The data support the alternative hypothesis of a multiple rare variant model, possibly consisting in distinct variants in different populations, influencing VEGF serum levels

    Thermal balance of wet-steam turbines in nuclear power plants: a case study

    Get PDF
    Conventional methodology is applied in this study to estimate the efficiency of nuclear power generation and the electrical power that is generated at a nuclear plant built in the nineteen-sixties. A simulation of the whole power plant is conducted with this methodology. The characteristic parameters from the study are compared with those estimated by the manufacturer for its on-design operation mode. Furthermore, the model calculates the anticipated pressures, temperatures, mass flows and electrical power on the basis of the data from various performance tests. These estimated parameters are then compared with real values measured in the plant. The objective of the present paper is to study whether the conventional approach is acceptable for the simulation of the parameters of the power station, and to identify areas where the results of the simulation may be improved, in order to minimize the deviations between the simulated parameters and the actual measurements

    Microglia Are Mediators of Borrelia burgdorferi–Induced Apoptosis in SH-SY5Y Neuronal Cells

    Get PDF
    Inflammation has long been implicated as a contributor to pathogenesis in many CNS illnesses, including Lyme neuroborreliosis. Borrelia burgdorferi is the spirochete that causes Lyme disease and it is known to potently induce the production of inflammatory mediators in a variety of cells. In experiments where B. burgdorferi was co-cultured in vitro with primary microglia, we observed robust expression and release of IL-6 and IL-8, CCL2 (MCP-1), CCL3 (MIP-1α), CCL4 (MIP-1β) and CCL5 (RANTES), but we detected no induction of microglial apoptosis. In contrast, SH-SY5Y (SY) neuroblastoma cells co-cultured with B. burgdorferi expressed negligible amounts of inflammatory mediators and also remained resistant to apoptosis. When SY cells were co-cultured with microglia and B. burgdorferi, significant neuronal apoptosis consistently occurred. Confocal microscopy imaging of these cell cultures stained for apoptosis and with cell type-specific markers confirmed that it was predominantly the SY cells that were dying. Microarray analysis demonstrated an intense microglia-mediated inflammatory response to B. burgdorferi including up-regulation in gene transcripts for TLR-2 and NFκβ. Surprisingly, a pathway that exhibited profound changes in regard to inflammatory signaling was triggering receptor expressed on myeloid cells-1 (TREM1). Significant transcript alterations in essential p53 pathway genes also occurred in SY cells cultured in the presence of microglia and B. burgdorferi, which indicated a shift from cell survival to preparation for apoptosis when compared to SY cells cultured in the presence of B. burgdorferi alone. Taken together, these findings indicate that B. burgdorferi is not directly toxic to SY cells; rather, these cells become distressed and die in the inflammatory surroundings generated by microglia through a bystander effect. If, as we hypothesized, neuronal apoptosis is the key pathogenic event in Lyme neuroborreliosis, then targeting microglial responses may be a significant therapeutic approach for the treatment of this form of Lyme disease
    corecore