574 research outputs found

    Acute idiopathic pericarditis: current immunological theories

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    Alida LP Caforio,1 Renzo Marcolongo,2 Antonio Brucato,3 Luca Cantarini,4 Massimo Imazio,5 Sabino Iliceto11Division of Cardiology, Department of Cardiology, Thoracic and Vascular Sciences, University of Padua, Padua; 2Haematology and Clinical Immunology, Department of Medicine, University of Padua, Padua, 3Internal Medicine, Ospedali Riuniti, Bergamo, 4Rheumatology Unit, Policlinico Le Scotte, University of Siena, Siena, 5Department of Cardiology, Maria Vittoria Hospital, Torino, ItalyAbstract: Idiopathic recurrent acute pericarditis (IRAP) is a rare disease of suspected immune-mediated pathogenesis. It represents a diagnosis of exclusion. It is necessary to rule out infectious and noninfectious causes of pericardial inflammation, including systemic autoimmune and immune-related disorders, eg, Sjögren's disease, systemic lupus erythematosus. Since pericarditis may precede diagnosis of these disorders, IRAP diagnosis is often made after a long follow-up. According to the two main pathogenetic theories IRAP may represent an organ-specific autoimmune disease or an autoinflammatory disease (AInfD). The main evidence for autoimmunity in IRAP is provided by the detection of serum antiheart and antiintercalated-disk autoantibodies, and the response to anti-inflammatory or immunosuppressive therapy. The findings of familial forms and of proinflammatory cytokines in the pericardial fluid in IRAP would be in keeping with both organ-specific autoimmune disease and AInfD. In fact, AInfD are genetic disorders characterized by primary dysfunction of the innate immune system, due to mutations of genes involved in the regulation of the inflammatory response, in the absence of antigen specific T cells or autoantibodies. In AInfD there are active disease phases with raised non-cardiac specific inflammatory markers, such as C-reactive protein, as well as symptom-free intervals with possible C-reactive protein normalization. A minority of IRAP patients (6%) carry a mutation in the TNFRSF1A gene, encoding the receptor for tumor necrosis factor-alfa. This suggests that some IRAP patients may have an atypical or subclinical form of AInfD. Thus, IRAP may represent a syndrome with distinct pathogenetic mechanisms in different patients' subsets.Keywords: pericarditis, autoimmunity, autoantibodies, heart disease, immune factor

    Molecular Hydrogen Formation on Low Temperature Surfaces in Temperature Programmed Desorption Experiments

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    The study of the formation of molecular hydrogen on low temperature surfaces is of interest both because it allows to explore elementary steps in the heterogeneous catalysis of a simple molecule and because of the applications in astrochemistry. Here we report results of experiments of molecular hydrogen formation on amorphous silicate surfaces using temperature-programmed desorption (TPD). In these experiments beams of H and D atoms are irradiated on the surface of an amorphous silicate sample. The desorption rate of HD molecules is monitored using a mass spectrometer during a subsequent TPD run. The results are analyzed using rate equations and the activation energies of the processes leading to molecular hydrogen formation are obtained from the TPD data. We show that a model based on a single isotope provides the correct results for the activation energies for diffusion and desorption of H atoms. These results can thus be used to evaluate the formation rate of H_2 on dust grains under the actual conditions present in interstellar clouds.Comment: 30 pages, 1 table, 6 figures. Published versio

    Applied Cyberpsychology: Military and Defence Applications

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    Virtual environments are synthetic computer simulations that represent activities at a high degree of realism. Virtual environments have numerous applications for military and defence purposes, ranging from allowing personnel to experience realistic, high-pressure situations with a sense of presence, but in the absence of real world risk, to modelling threats to national and international infrastructure to improve resilience. Emerging opportunities also exist for communication and intelligence gathering, exploring on-line social cognition and group behaviour, and understanding how to mitigate the negative effects of combat-related stress disorders, for example. In this chapter we introduce psychological theory and contemporary cyberpsychology research, and offer an albeit very brief introduction to the rapidly developing application of technology to better understand human behaviour and facilitate performance for military and defence purposes

    Genetic diversity and dynamics of the Noir Marron settlement in French Guyana : A study combining mitochondrial DNA, Y chromosome and HTLV-1 genotyping [Abstract]

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    The Noir Marron are the direct descendants of thousands of African slaves deported to the Guyanas during the Atlantic Slave Trade and later escaped mainly from Dutch colonial plantations. Six ethnic groups are officially recognized, four of which are located in French Guyana: the Aluku, the Ndjuka, the Saramaka, and the Paramaka. The aim of this study was: (1) to determine the Noir Marron settlement through genetic exchanges with other communities such as Amerindians and Europeans; (2) to retrace their origins in Africa. Buffy-coat DNA from 142 Noir Marron, currently living in French Guyana, were analyzed using mtDNA (typing of SNP coding regions and sequencing of HVSI/II) and Y chromosomes (typing STR and SNPs) to define their genetic profile. Results were compared to an African database composed by published data, updated with genotypes of 82 Fon from Benin, and 128 Ahizi and 63 Yacouba from the Ivory-Coast obtained in this study for the same markers. Furthermore, the determination of the genomic subtype of HTLV-1 strains (env gp21 and LTR regions), which can be used as a marker of migration of infected populations, was performed for samples from 23 HTLV-1 infected Noir Marron and compared with the corresponding database. MtDNA profiles showed a high haplotype diversity, in which 99% of samples belonged to the major haplogroup L, frequent in Africa. Each haplotype was largely represented on the West African coast, but notably higher homologies were obtained with the samples present in the Gulf of Guinea. Y Chromosome analysis revealed the same pattern, i.e. a conservation of the African contribution to the Noir Marron genetic profile, with 98% of haplotypes belonging to the major haplogroup E1b1a, frequent in West Africa. The genetic diversity was higher than those observed in African populations, proving the large Noir Marron’s fatherland, but a predominant identity in the Gulf of Guinea can be suggested. Concerning HTLV-1 genotyping, all the Noir Marron strains belonged to the large Cosmopolitan A subtype. However, among them 17/23 (74%) clustered with the West African clade comprizing samples originating from Ivory-Coast, Ghana, Burkina-Fasso and Senegal, while 3 others clustered in the Trans-Sahelian clade and the remaining 3 were similar to strains found in individuals in South America. Through the combined analyses of three approaches, we have provided a conclusive image of the genetic profile of the Noir Marron communities studied. The high degree of preservation of the African gene pool contradicts the expected gene flow that would correspond to the major cultural exchanges observed between Noir Marron, Europeans and Amerindians. Marital practices and historical events could explain these observations. Corresponding to historical and cultural data, the origin of the ethnic groups is widely dispatched throughout West Africa. However, all results converge to suggest an individualization from a major birthplace in the Gulf of Guinea

    Characterization and Testing of the Passive Magnetic Attitude Control System for the 3U AstroBio CubeSat

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    AstroBio CubeSat is a mission funded by the Italian Space Agency aimed at validating novel lab-on-chip technology, that would enable the use of micro- and nanosatellites as autonomous orbiting laboratories for research in astrobiology. This 3U CubeSat is equipped with a passive magnetic attitude control system (PMACS), including permanent magnets and hysteresis strips, which allows for stabilizing the spacecraft with the longitudinal axis in the direction of the geomagnetic field vector. This work presents the process followed for the experimental characterization of the system, performed on the engineering unit of the satellite by using a Helmholtz cage facility and a spherical air-bearing to recreate environmental conditions similar to the ones experienced during the orbital motion. The hysteresis strips are characterized starting from the determination of the hysteresis loop, from which the energy dissipation per cycle and the apparent magnetic permeability are extracted. Tests performed by using the Helmholtz cage and the air-bearing facility allows for further investigating the damping torque produced by the PMACS and validating the abovementioned parameters. Numerical analysis is then used to select the number of permanent magnets which allows for achieving a pointing accuracy within an error of 10° within 24 h from the deployment. The analysis of the flight data supports the results obtained from the experimental test campaigns, confirming the effectiveness of the proposed methods and of the PMACS design
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