3,391 research outputs found

    Administration of Brevibacillus laterosporus spores as a poultry feed additive to inhibit house fly development in feces: A new eco-sustainable concept

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    ABSTRACT The success of a microbial pesticide application against house flies developing in manure should accomplish the uniform mixing of active ingredients with this breeding medium, thus enhancing residual effects. The oral administration of the entomopathogenic bacterium Brevibacillus laterosporus to caged poultry species allows the homogeneous incorporation of its active ingredients with fly breeding media. Feces from treated broilers or hens show toxicity against exposed fly adults and larvae. Insecticidal effects are concentration-dependent with a lethal median concentration (LC50) value of 1.34 × 108 and 0.61 × 108 spores/g of feces for adults and larvae, respectively. Manure toxicity against flies was maintained as long as chickens were fed a diet containing adequate concentrations of B. laterosporus spores. Toxicity significantly decreased after spore administration to birds was interrupted. When poultry diet contained 1010 spores/g, mortality of flies reared on feces exceeded 80%. The use of B. lateroporus spores as a feed additive in poultry production systems fostering a more integrated approach to farming is discussed

    Hlt1 Muon Alley Description

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    This note describes the LHCb Hlt1 muon alley, which is part of the High Level Trigger. It is intended to confirm the L0 muon trigger and reduce the bandwidth. The performance presented here is done using about 1000 simulated data of some relevant muon channels and 200k of minimum bias events

    Bronchoalveolar lavage causes decrease in PaO2, increase in (A-a) gradient value and bronchoconstriction in asthmatics.

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    7siAbstract The aims of this study were to (1) record the changes of (arterial oxygen partial pressure) PaO2, (arterial carbon dioxide partial pressure) PaCO2, (percentage saturation of haemoglobin with oxygen in arterial blood) SaO2 and alveolar-arterial (A-a) oxygen gradiant resulting from bronchoalveolar lavage (BAL) in asthmatic and normal subjects; (2) measure changes in forced expiratory volume in 1 s (FEV1), vital capacity forced (FVC) associated with BAL; and (3) assess possible predictive factors for the degree of hypoxaemia and impairment of spirometry resulting from BAL. Bronchoscopy and BAL (150 ml) were performed in 24 asthmatics and 15 healthy subjects. Serial arterial blood samples (radial artery) were obtained in all subjects: T1 and before T2 after local anaesthesia; T3 at end of bronchoscopy; T4 after BAL and 5 min, 15 min, 1 h, 2 h, 8 h and 24 h (T5-T10) after the procedure, FEV1 and FVC were measured immediately before and 5 min afer bronchoscopy. Baseline PaO2 was lower in asthmatics (10.2 +/- 0.8 kPa) than in healthy subjects (10.8 +/- 0.8). Both groups showed a significant decrease in PaO2, and a significant widening in (A-a) oxygen tension gradiant at T3-9, with respect to T1 (P < 0.05). PaO2 reached a significantly lower value in asthmatics (7.1 +/- 0.6 kPa) than in HS (7.7 +/- 0.5; P < 0.05). In asthmatics, FEV1, FVC and the ratio FEV1/FVC decreased significantly after BAL (P < 0.001). In healthy subjects, FEV1 and FVC decreased significantly (P < 0.001), whereas FEV1/FVC did not. The fall in FEV1 after BAL was significantly greater in asthmatics (32.4 +/- 10.0%) than in healthy subjects (17.7 +/- 4.6; P < 0.001). Severity of asthma, basline FEV1 or initial PaO2 did not predict the degree of hypoxaemia or the fall of FEV1. It is concluded that BAL causes more severe hypoxaemia and a greater decrease in FEV1 in asthmatics compared to healthy subjects, strongly supporting the recommendation of special caution and careful monitoring when BAL is undertaken in asthmatics.nonemixedSPANEVELLO A; MIGLIORI GB; SATTA A; SHARARA A; BALLARDINI L; IND PW; NERI M.Spanevello, Antonio; Migliori, Gb; Satta, A; Sharara, A; Ballardini, L; Ind, Pw; Neri, M

    Formation mechanisms and phase stability of solid-state grown cspbi3 perovskites

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    CsPbI3 inorganic perovskite is synthesized by a solvent-free, solid-state reaction, and its structural and optical properties can be deeply investigated using a multi-technique approach. X-ray Diffraction (XRD) and Raman measurements, optical absorption, steady-time and time-resolved luminescence, as well as High-Resolution Transmission Electron Microscopy (HRTEM) imaging, were exploited to understand phase evolution as a function of synthesis time length. Nanoparticles with multiple, well-defined crystalline domains of different crystalline phases were observed, usually surrounded by a thin, amorphous/out-of-axis shell. By increasing the synthesis time length, in addition to the pure α phase, which was rapidly converted into the δ phase at room temperature, a secondary phase, Cs4PbI6, was observed, together with the 715 nm-emitting γ phase

    Superconductivity on the localization threshold and magnetic-field-tuned superconductor-insulator transition in TiN films

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    Temperature- and magnetic-field dependent measurements of the resistance of ultrathin superconducting TiN films are presented. The analysis of the temperature dependence of the zero field resistance indicates an underlying insulating behavior, when the contribution of Aslamasov-Larkin fluctuations is taken into account. This demonstrates the possibility of coexistence of the superconducting and insulating phases and of a direct transition from the one to the other. The scaling behavior of magnetic field data is in accordance with a superconductor-insulator transition (SIT) driven by quantum phase fluctuations in two-dimensional superconductor. The temperature dependence of the isomagnetic resistance data on the high-field side of the SIT has been analyzed and the presence of an insulating phase was confirmed. A transition from the insulating to a metallic phase is found at high magnetic fields, where the zero-temperature asymptotic value of the resistance being equal to h/e^2.Comment: 5 pages, 4 eps figures, RevTeX4, Published versio

    Soft x-ray spectroscopy experiments on the near K-edge of B in MB2 (M=Mg, Al, Ta, and Nb)

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    Soft X-ray absorption and emission measurements are performed for the K- edge of B in MB2_2 (M=Mg, Al, Ta and Nb). Unique feature of MgB2_2 with a high density of B 2pxy(σ)p_{xy}(\sigma)-state below and above the Fermi edge, which extends to 1 eV above the edge, is confirmed. In contrast, the B 2pp density of states in AlB2_2 and TaB2_2, both of occupied and unoccupied states, decreased linearly towards the Fermi energy and showed a dip at the Fermi energy. Furthermore, there is a broadening of the peaks with pσp\sigma-character in XES and XAS of AlB2_2, which is due to the increase of three dimensionality in the pσp\sigma-band in AlB2_2. The DOS of NbB2_2 has a dip just below the Fermi energy. The present results indicate that the large DOS of B-2pσp\sigma states near the Fermi energy are crucial for the superconductivity of MgB2_2.Comment: 3 pages text and 4 pages figures. accepted for publication to Phys. Rev.

    Electric field gradients in s-, p- and d-metal diborides and the effect of pressure on the band structure and Tc_c in MgB2_2

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    Results of FLMTO-GGA (full-potential linear muffin-tin orbital -- generalized gradient approximation) calculations of the band structure and boron electric field gradients (EFG) for the new medium-Tc_c superconductor (MTSC), MgB2_2, and related diborides MB2_2, M=Be, Al, Sc, Ti, V, Cr, Mo and Ta are reported. The boron EFG variations are found to be related to specific features of their band structure and particularly to the M-B hybridization. The strong charge anisotropy at the B site in MgB2_2 is completely defined by the valence electrons - a property which sets MgB2_2 apart from other diborides. The boron EFG in MgB2_2 is weakly dependent of applied pressure: the B p electron anisotropy increases with pressure, but it is partly compensated by the increase of core charge assymetry. The concentration of holes in bonding σ\sigma bands is found to decrease slightly from 0.067 to 0.062 holes/B under a pressure of 10 GPa. Despite a small decrease of N(EF_F), the Hopfield parameter increases with pressure and we believe that the main reason for the reduction under pressure of the superconducting transition temperature, Tc_c, is the strong pressure dependence of phonon frequencies, which is sufficient to compensate the electronic effects.Comment: 12 pages, 3 figure

    Small Fermi energy and phonon anharmonicity in MgB_2 and related compounds

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    The remarkable anharmonicity of the E_{2g} phonon in MgB_2 has been suggested in literature to play a primary role in its superconducting pairing. We investigate, by means of LDA calculations, the microscopic origin of such an anharmonicity in MgB_2, AlB_2, and in hole-doped graphite. We find that the anharmonic character of the E_{2g} phonon is essentially driven by the small Fermi energy of the sigma holes. We present a simple analytic model which allows us to understand in microscopic terms the role of the small Fermi energy and of the electronic structure. The relation between anharmonicity and nonadiabaticity is pointed out and discussed in relation to various materials.Comment: 5 pages, 2 figures replaced with final version, accepted on Physical Review

    Circulating haematopoietic and endothelial progenitor cells are decreased in COPD

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    Circulating CD34+ cells are haemopoietic progenitors that may play a role in tissue repair. No data are available on circulating progenitors in chronic obstructive pulmonary disease (COPD). Circulating CD34+ cells were studied in 18 patients with moderate-to-severe COPD (age: mean+/-sd 68+/-8 yrs; forced expiratory volume in one second: 48+/-12% predicted) and 12 controls, at rest and after endurance exercise. Plasma concentrations of haematopoietic growth factors (FMS-like tyrosine kinase 3 (Flt3) ligand, kit ligand), markers of hypoxia (vascular endothelial growth factor (VEGF)) and stimulators of angiogenesis (VEGF, hepatocyte growth factor (HGF)) and markers of systemic inflammation (tumour necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-8) were measured. Compared with the controls, the COPD patients showed a three-fold reduction in CD34+ cell counts (3.3+/-2.5 versus 10.3+/-4.2 cells.microL-1), and a 50% decrease in AC133+ cells. In the COPD patients, progenitor-derived haemopoietic and endothelial cell colonies were reduced by 30-50%. However, four COPD patients showed progenitor counts in the normal range associated with lower TNF-alpha levels. In the entire sample, CD34+ cell counts correlated with exercise capacity and severity of airflow obstruction. After endurance exercise, progenitor counts were unchanged, while plasma Flt3 ligand and VEGF only increased in the COPD patients. Plasma HGF levels were higher in the COPD patients compared with the controls and correlated inversely with the number of progenitor-derived colonies. In conclusion, circulating CD34+ cells and endothelial progenitors were decreased in chronic obstructive pulmonary disease patients and could be correlated with disease severity
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