52 research outputs found

    Study of Neutron From a Dense Plasma Focus Paco Instrument by Means of Nuclear Tracks Detectors

    Get PDF
    A most interesting feature of dense plasma foci is the acceleration of charge particle at energy in the range of MeV per nucleon. Using deuterium gas, this devices produce fusion D-D reactions, generation fast neutron pulses (~ 2.5 MeV). The device used in the present work is a Mather-type dense plasma focus, called PACO. It is a 2kJ device at 31 kV, with an oxygen-free copper anode, 50 mm long with 40 mm diameter. The coaxial cathode is formed by ten copper rods arranged in a squirrel cage configuration at a radius of 50 mm. The insulator in an annular Pyrex® tube located at the base of the anode. The energy store is provided by four 1 μF (40 kV, 40 nH) capacitors in parallel. The plasma focus was operated at 1.5 mb deuterium gas pressure. Neutron and accelerated particles are analyzed with material detectors (CR-39 Lantrack®) for different conditions. A detailed study is made of track diameters when the plastic is chemically etched with, 6N KOH at 60°C (±1) for 12

    Defining Early Human NK Cell Developmental Stages in Primary and Secondary Lymphoid Tissues

    Get PDF
    A better understanding of human NK cell development in vivo is crucial to exploit NK cells for immunotherapy. Here, we identified seven distinctive NK cell developmental stages in bone marrow of single donors using 10-color flow cytometry and found that NK cell development is accompanied by early expression of stimulatory co-receptor CD244 in vivo. Further analysis of cord blood (CB), peripheral blood (PB), inguinal lymph node (inLN), liver lymph node (liLN) and spleen (SPL) samples showed diverse distributions of the NK cell developmental stages. In addition, distinctive expression profiles of early development marker CD33 and C-type lectin receptor NKG2A between the tissues, suggest that differential NK cell differentiation may take place at different anatomical locations. Differential expression of NKG2A and stimulatory receptors (e.g. NCR, NKG2D) within the different subsets of committed NK cells demonstrated the heterogeneity of the CD56brightCD16+/− and CD56dimCD16+ subsets within the different compartments and suggests that microenvironment may play a role in differential in situ development of the NK cell receptor repertoire of committed NK cells. Overall, differential in situ NK cell development and trafficking towards multiple tissues may give rise to a broad spectrum of mature NK cell subsets found within the human body

    FT-IR Investigation of Methoxy Substituted Benzenes Adsorbed on Solid Acid Catalysts

    No full text
    The nature of the interaction on two different catalysts (zeolite BEA and \u3b3-alumina) of some aromatic substrates, 1,2-methylendioxybenzene, 1,2-ethylendioxybenzene, and 1,2-dimethoxybenzene, have been investigated by FT-IR spectroscopy. FT-IR data suggest that the adsorption of 1,2-methylendioxybenzene occurs through oxygen atoms and the molecule maintains the original puckered conformation, whereas the planar structure due to the absence of a fused ring in the case of 1,2-dimethoxybenzene and the twisted conformation of 1,2-ethylendioxybenzene cause an orientation of the molecules parallel to the catalyst surface, with the benzene ring directly interacting to it. The puckered conformation of MDB leads the benzene ring to be electron-deficient, then deactivated toward alkylation, such as confirmed by the obtained catalytic results, which show that MDB is totally not reactive using the investigated heterogeneous catalysts, while in the traditional homogeneous system shows a reactivity comparable to the other considered substrates

    Esferocitosis Familiar Congénita

    No full text

    Cross-cultural adaptation, and validity of the Italian version of the upper limb functional index (ULFI-I)

    No full text
    Background: Outcome measures are the scientific basis for assessment and comparison of the effects of rehabilitative interventions. Among the instruments proposed for the evaluation of musculoskeletal disorders of the upper limb, the Upper Limb Functional Index (ULFI) was recently validated and translated into several languages, but it does not yet exist an Italian version yet. Objective: To obtain an Italian validated version of ULFI, called ULFI-I. Materials & Methods: The translation process was conducted following the international guidelines of the forward/backward translation. The ULFI-I was subsequently validated by calculating: I) internal consistency (Cronbach's \u3b1 and item-to-total correlation), 2) criterion validity (correlation r with the Disabilities of the Arm, Shoulder and Hand Questionnaire, DASH), and 3) test-retest reliability (ICC2,1) and measurement error (Standard Error of measurement, SEM and Minimal Detectable Change, MDC90). For the first two points we used a sample of 57 patients with upper limb orthopedic conditions, while the analysis of the reliability required a further administration of the questionnaire carried out 3 days before on 33 subjects. I. Statistical analysis showed good levels of internal consistency (Cronbach's \u3b1=.90, item-to-total correlation between .45 and .73), high criterion validity (r=.81, p<0.01) and excellent reliability test-retest reliability (ICC2,1=.94, CI=.89-.97). The SEM was found to be equal to 5 points, with a MDC90 estimated at 12 points. Conclusion: In this study the ULFI-I showed good psychometric properties, combined with speed and ease of administration and scoring. Its use will facilitate the comparison of data collected in Italy with international studies, ensuring greater uniformity of assessment

    Isotropic and anisotropic components of neutron emissions at the FN-II and PACO dense plasma focus devices

    No full text
    The average angular distribution of neutron emissions has been measured in the Fuego Nuevo II (FN-II) dense plasma focus device (5 kJ) by means of CR-39 plastic nuclear track detectors. When pure deuterium is used as the filling gas, the data can be adjusted to a Gaussian function, related to anisotropic emission, superposed on a constant pedestal, related to isotropic emission. When deuterium-argon admixtures are used, the anisotropic contribution is best represented by a parabola. The same analysis is applied to previously reported results, for fewer shots, in pure deuterium from the PACO device, which is similar in size to the FN-II. In both devices the anisotropic component is smaller than the isotropic one, but with different features. In PACO the anisotropic component is concentrated on a large narrow beam around the axis, but its contribution to the total neutron yield is significantly smaller than in the FN-II, where the anisotropic component spreads over a wider range. The neutron flux per shot is monitored in both devices with calibrated silver activation detectors, at 20degrees and at 90degrees from the axis. The average values of the neutron flux at these two angles are used, along with the angular distributions obtained form the track detectors, in order to estimate the absolute neutron yield of both the isotropic and the anisotropic contributions. From examining different groups of shots, it is found that the shape of the angular distribution is important in the estimation of anisotropy, and that the value usually reported, as the ratio of neutron counts head-on and side-on, as measured by activation counters, may be misleading
    • …
    corecore