3,067 research outputs found

    Chiral properties of hematite ({\alpha}-Fe2O3) inferred from resonant Bragg diffraction using circularly polarized x-rays

    Full text link
    Chiral properties of the two phases - collinear motif (below Morin transition temperature, TM=250 K) and canted motif (above TM) - of magnetically ordered hematite ({\alpha}-Fe2O3) have been identified in single crystal resonant x-ray Bragg diffraction, using circular polarized incident x-rays tuned near the iron K-edge. Magneto-electric multipoles, including an anapole, fully characterize the high-temperature canted phase, whereas the low-temperature collinear phase supports both parity-odd and parity-even multipoles that are time-odd. Orbital angular momentum accompanies the collinear motif, while it is conspicuously absent with the canted motif. Intensities have been successfully confronted with analytic expressions derived from an atomic model fully compliant with chemical and magnetic structures. Values of Fe atomic multipoles previously derived from independent experimental data, are shown to be completely trustworthy

    Thermodynamic properties of CO2 + SO2 + CH4 mixtures over wide ranges of temperature and pressure. Evaluation of CO2/SO2 co-capture in presence of CH4 for CCS

    Get PDF
    In this work, density, vapor-liquid equilibrium and speed of sound measurements of the mixtures [CO2+ 4.72 mol% SO2+ 1.85 mol% CH4] and [CO2+ 0.09 mol% SO2+ 1.54 mol% CH4] were performed over the temperature range 263-373 K and at pressures of up to 30 MPa for density and up to 190 MPa for speed of sound. For the speed of sound measurements, the mixtures were doped with congruent to 0.8 mol% CH3OH. We compared our results to the values calculated using an extended version of the equation of state for combustion gases (EOSCG) that includes binary models for the CO2+ SO2 and CO2+ CH4 subsystems, and a perturbed-chain statistical associating fluid theory (PC-SAFT) equation of state, validating both equations in this way. From our experimental results, we evaluated the impact of the simultaneous presence of SO2 and CH4 as impurities in anthropogenic CO2 on selected parameters for carbon capture and storage technology. With the understanding that chemical effects have not been considered, we concluded that the presence of 4.72 mol% SO2 compensates for the negative effect of 1.85 mol% CH4 on most of the studied parameters, resulting in a favorable fluid for carbon, capture and storage, contrary to the mixture with 0.09 mol% SO2 and 1.54 mol% CH4

    Antiferro--quadrupolar structures in UPd3_3 inferred from x-ray resonant Bragg diffraction

    Full text link
    A systematic analysis of resonant x-ray Bragg diffraction data for UPd3_3, with signal enhancement at the U MIV_{IV} edge, including possible structural phase-transitions leads to a new determination of the space groups of the material in the phases between T0=7.8T_0 = 7.8 K and T+1T_{+1} = 6.9 K as P2221_1 and between T−1T_{-1} = 6.7 K and T2T_{2} = 4.4 K as space group P21_1. In addition, the quadrupolar order-parameters, , inferred from diffraction data in the phase between $T_{-1}$ and $T_{2}$, are and atthe(103)Braggreflection,and at the (103) Bragg reflection, and at the (104) reflection.Comment: 13 pages, 4 figure

    Removal of sialic acid from bull sperm decreases motility and mucus penetration ability but increases zona pellucida binding and polyspermic penetration in vitro

    Get PDF
    peer-reviewedThis study tested the hypothesis that sperm sialic acid (Sia) is required to reach the site of fertilization, and that successful fertilization requires recognition of Sia from both the sperm and oocyte to occur. In addition, it has recently been reported that Siglecs (Sia-binding-immunoglobulin-like lectins) are present on the sperm surface. Thus, the possibility that the recognition of oocyte Sia was sperm-Siglec-mediated was also addressed. Sperm exposed to neuraminidase (NMase) exhibited lower overall and progressive motility, which translated to a decreased ability to swim through cervical mucus from cows in oestrus. In addition, when either sperm or cumulus-oocyte complexes (COCs) were treated with NMase, a decrease in cleavage and blastocyst rate was observed. However, incubation of sperm with increasing concentrations of anti-Siglec-2, -5, -6 and -10 antibodies prior to fertilization had no effect on their fertilizing ability. Interestingly, treatment with NMase increased the number of sperm bound to the ZP but also the rate of polyspermic fertilization. Flow cytometry analysis revealed no differences in the percentage of capacitated or acrosome-reacted sperm. These results suggest that Sia are required to reach the site of fertilization but need to be removed for sperm-oocyte interaction. However, fine regulation is needed to avoid abnormal fertilization which can lead to impaired embryo development

    The Air Microwave Yield (AMY) experiment - A laboratory measurement of the microwave emission from extensive air showers

    Full text link
    The AMY experiment aims to measure the microwave bremsstrahlung radiation (MBR) emitted by air-showers secondary electrons accelerating in collisions with neutral molecules of the atmosphere. The measurements are performed using a beam of 510 MeV electrons at the Beam Test Facility (BTF) of Frascati INFN National Laboratories. The goal of the AMY experiment is to measure in laboratory conditions the yield and the spectrum of the GHz emission in the frequency range between 1 and 20 GHz. The final purpose is to characterise the process to be used in a next generation detectors of ultra-high energy cosmic rays. A description of the experimental setup and the first results are presented.Comment: 3 pages -- EPS-HEP'13 European Physical Society Conference on High Energy Physics (July, 18-24, 2013) at Stockholm, Swede

    The safety and clinical effectiveness of rapid infusion with CT-P10 in patients with non-Hodgkin's lymphoma or chronic lymphocytic leukemia: A retrospective non-interventional post-authorization safety study in Europe

    Get PDF
    Rapid infusion (RI) of the rituximab biosimilar CT-P10 is currently only an approved treatment regimen for the treatment of rheumatoid arthritis. Although both CT-P10 and reference rituximab are known to be frequently administered using a RI regimen (≤90 min) in clinical practice, published data on the safety of RI of CT-P10 in patients with NHL and CLL are limited. Hence, this study collected real-world safety and effectiveness data on RI-CT-P10 from the medical records of 196 patients with NHL or CLL in 10 European centers, 6 months after the date of the first RI (index date); the infusion-related reaction (IRR) rate was compared to previously published data. Ten percent (95% confidence interval 6%–15%; n = 20/196) of patients experienced an infusion-related reaction (IRR) on day 1–2 post-index, which was not significantly different (p = 0.45) to the IRR rate for rituximab described in a previous meta-analysis (8.8%). During the observation period, 2% of patients experienced grade 3–5 IRRs and 85% (n = 166) experienced an adverse event (non-IRR). The most common reason for discontinuation of first-line CT-P10 was planned treatment completion (81%; n = 158). Complete response and partial response to CT-P10 was observed in 74% (n = 142/192) and 22% (n = 42/192) of patients, respectively. The results of this real-world study demonstrate that the safety and effectiveness profile of RI-CT-P10 is similar to RI of reference rituximab and therefore support the current use of RI-CT-P10 in patients with NHL and CLL

    Endothelial Progenitor Cells as a Potential Biomarker in Interstitial Lung Disease Associated with Rheumatoid Arthritis

    Get PDF
    Interstitial lung disease (ILD) increases morbidity and mortality in patients with rheumatoid arthritis (RA). Although the pathogenesis of ILD associated with RA (RA-ILD(+)) remains poorly defined, vascular tissue is crucial in lung physiology. In this context, endothelial progenitor cells (EPC) are involved in endothelial tissue repair. However, little is known about their implication in RA-ILD(+). Accordingly, we aimed to investigate the potential role of EPC related to endothelial damage in RA-ILD(+). EPC quantification in peripheral blood from 80 individuals (20 RA-ILD(+) patients, 25 RA-ILD(-) patients, 21 idiopathic pulmonary fibrosis (IPF) patients, and 14 healthy controls) was performed by flow cytometry. EPC were considered as CD34(+), CD45(low), CD309(+) and CD133(+). A significant increase in EPC frequency in RA-ILD(+) patients, as well as in RA-ILD(-) and IPF patients, was found when compared with controls (p < 0.001, p = 0.02 and p < 0.001, respectively). RA-ILD(+) patients exhibited a higher EPC frequency than the RA-ILD(-) ones (p = 0.003), but lower than IPF patients (p < 0.001). Our results suggest that EPC increase may represent a reparative compensatory mechanism in patients with RA-ILD(+). The degree of EPC frequency may help to identify the presence of ILD in RA patients and to discriminate RA-ILD(+) from IPF
    • …
    corecore