660 research outputs found

    Gold catalysts supported on ceria doped by rare earth metals for water gas shift reaction: Influence of the preparation method

    Get PDF
    Cataloged from PDF version of article.Gold catalysts based on ceria, doped by various RE metals (La, Sm, Gd, Yb, Y) were studied. The influence of the preparation methods on structure, properties and catalytic activity in the WGS reaction was investigated. The catalysts' supports were prepared using two different methods: co-precipitation (CP) and mechanochemical activation (MA). The catalysts were tested in a wide temperature interval without and after reactivation. All samples were characterized using a combination of X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), Raman spectroscopy (RS) and X-ray photoelectron spectroscopy (XPS) and TPR. It was found that the catalytic activity of MA catalysts is higher than CP ones. The gold catalysts based on ceria doped by Yb and Sm exhibited the highest activity. After reactivation in air the MA samples almost kept the WGS activity same, while the CP catalysts increased it. The catalysts of a single- and double-phase structure are formed as a result of CP and MA preparation, respectively. There are no big differences in the gold particles size (2-3 nm) depending on dopants and on the preparation techniques. The RS spectra analysis indicates that most probably the oxygen vacancies are adjacent to Me(3+) dopant and the ceria structure seems to be better ordered than in the case of alumina as a dopant. There is no distinct correlation between reducibility and WGS activity. The XPS analysis disclose positively charged gold particles in addition to metallic gold within a surface region of fresh samples and only metallic gold on the samples after catalytic processing. There is no simple correlation between the concentration of Ce(3+) in the samples and their WGS activity. (C) 2009 Elsevier B.V. All rights reserved

    Glenohumeral joint capsular tissue tension loading correlates moderately with shear wave elastography: a cadaveric investigation

    Get PDF
    Purpose The purpose of this study was to investigate changes in the mechanical properties of capsular tissue using shear wave elastography (SWE) and a durometer under various tensile loads, and to explore the reliability and correlation of SWE and durometer measurements to evaluate whether SWE technology could be used to assess tissue changes during capsule tensile loading. Methods The inferior glenohumeral joint capsule was harvested from 10 fresh human cadaveric specimens. Tensile loading was applied to the capsular tissue using 1-, 3-, 5-, and 8-kg weights. Blinded investigators measured tissue stiffness and hardness during loading using SWE and a durometer, respectively. Intraobserver reliability was established for SWE and durometer measurements using intraclass correlation coefficients (ICCs). The Pearson product-moment correlation was used to assess the associations between SWE and durometer measurements. Results The ICC3,5 for durometer measurements was 0.90 (95% confidence interval [CI], 0.79 to 0.96; P<0.001) and 0.95 (95% CI, 0.88 to 0.98; P<0.001) for SWE measurements. The Pearson correlation coefficient values for 1-, 3-, and 5-kg weights were 0.56 (P=0.095), 0.36 (P=0.313), and -0.56 (P=0.089), respectively. When the 1- and 3-kg weights were combined, the ICC3,5 was 0.72 (P<0.001), and it was 0.62 (P<0.001) when the 1-, 3-, and 5-kg weights were combined. The 8-kg measurements were severely limited due to SWE measurement saturation of the tissue samples. Conclusion This study suggests that SWE is reliable for measuring capsular tissue stiffness changes in vitro at lower loads (1 and 3 kg) and provides a baseline for the non-invasive evaluation of effects of joint loading and mobilization on capsular tissues in vivo

    Colonist, 1889-02-15

    Get PDF
    The Colonist began on 6 March 1886, changing its name to The Newfoundland Colonist after 18 July 1891. Having printed local and international news Monday to Saturday for six years, the paper came to an abrupt end when its offices were destroyed in The Great Fire of 8 July 1892.Title variations recorded in Alternative Title, as needed

    Influence of antigen density and TLR ligands on preclinical efficacy of a VLP-based vaccine against peanut allergy.

    Get PDF
    BACKGROUND Virus-like particle (VLP) Peanut is a novel immunotherapeutic vaccine candidate for the treatment of peanut allergy. The active pharmaceutical ingredient represents cucumber mosaic VLPs (CuMVTT -VLPs) that are genetically fused with one of the major peanut allergens, Ara h 2 (CuMVTT -Ara h 2). We previously demonstrated the immunogenicity and the protective capacity of VLP Peanut-based immunization in a murine model for peanut allergy. Moreover, a Phase I clinical trial has been initiated using VLP Peanut material manufactured following a GMP-compliant manufacturing process. Key product characterization studies were undertaken here to understand the role and contribution of critical quality attributes that translate as predictive markers of immunogenicity and protective efficacy for clinical vaccine development. METHOD The role of prokaryotic RNA encapsulated within VLP Peanut on vaccine immunogenicity was assessed by producing a VLP Peanut batch with a reduced RNA content (VLP Peanut low RNA). Immunogenicity and peanut allergen challenge studies were conducted with VLP Peanut low RNA, as well as with VLP Peanut in WT and TLR 7 KO mice. Furthermore, mass spectrometry and SDS-PAGE based methods were used to determine Ara h 2 antigen density on the surface of VLP Peanut particles. This methodology was subsequently applied to investigate the relationship between Ara h 2 antigen density and immunogenicity of VLP Peanut. RESULTS A TLR 7 dependent formation of Ara h 2 specific high-avidity IgG antibodies, as well as a TLR 7 dependent change in the dominant IgG subclass, was observed following VLP Peanut vaccination, while total allergen-specific IgG remained relatively unaffected. Consistently, a missing TLR 7 signal caused only a weak decrease in allergen tolerability after vaccination. In contrast, a reduced RNA content for VLP Peanut resulted in diminished total Ara h 2 specific IgG responses, followed by a significant impairment in peanut allergen tolerability. The discrepant effect on allergen tolerance caused by an absent TLR 7 signal versus a reduced RNA content is explained by the observation that VLP Peanut-derived RNA not only stimulates TLR 7 but also TLR 3. Additionally, a strong correlation was observed between the number of Ara h 2 antigens displayed on the surface of VLP Peanut particles and the vaccine's immunogenicity and protective capacity. CONCLUSIONS Our findings demonstrate that prokaryotic RNA encapsulated within VLP Peanut, including antigen density of Ara h 2 on viral particles, are key contributors to the immunogenicity and protective capacity of the vaccine. Thus, antigenicity and RNA content are two critical quality attributes that need to be determined at the stage of manufacturing, providing robust information regarding the immunogenicity and protective capacity of VLP Peanut in the mouse which has translational relevance to the human setting

    A unified accretion-ejection paradigm for Black Hole X-ray Binaries

    Full text link
    We present a new picture for the central regions of Black Hole X-ray Binaries. In our view, these central regions have a multi-flow configuration which consists in (1) an outer standard accretion disc down to a transition radius r_J, (2) an inner magnetized accretion disc below r_J driving (3) a non relativistic self-collimated electron-proton jet surrounding, when adequate conditions for pair creation are met, (4) a ultra relativistic electron-positron beam. This accretion-ejection paradigm provides a simple explanation to the canonical spectral states by varying the transition radius r_J and disc accretion rate independently. Large values of r_J correspond to the Quiescent state for low m˙\dot m and the Hard state for larger m˙\dot m. These states are characterized by the presence of a steady electron-proton MHD jet emitted by the disc below r_J. The hard X-ray component is expected to form at the jet basis. When r_j becomes smaller than the marginally stable orbit r_i, the whole disc resembles a standard accretion disc, characteristic of the Soft state. Intermediate states correspond to situations where r_J ~ r_i. At large m˙\dot m, an unsteady pair cascade process is triggered within the jet axis, giving birth to ejection of relativistic pair blobs. This would correspond to the luminous intermediate state, with its associated superluminal motions. The variation of r_J independently of m˙\dot m is a necessary ingredient in this picture, arising from the presence of a large scale vertical magnetic field threading the disc.Comment: 15 pages, 2 figures. Accepted by A&A main journa

    Effects of acute treatment with a tryptophan-rich protein hydrolysate on plasma amino acids, mood and emotional functioning in older women

    Get PDF
    RATIONALE: Effective functioning of the neurotransmitter serotonin is important for optimal cognitive and emotional function. Dietary supplements able to increase availability to the brain of the precursor amino acid, tryptophan (TRP), and thereby enhance serotonin synthesis, can have measurable impact on these psychological processes. OBJECTIVES: This study involves a randomised controlled trial of a TRP-rich egg-white protein hydrolysate (DSM Nutritional Products Ltd., Switzerland) on plasma amino acids, cognition, mood and emotional processing in older women. METHODS: Following a baseline test day without treatment, 60 healthy women aged 45–65 years received drinks containing either 2 or 4 g of TRP-rich protein hydrolysate product or 3.11 g casein hydrolysate as a control. One hour later, they undertook a 2-h battery of cognitive and emotional tests. RESULTS: The TRP-rich protein hydrolysate produced the expected dose-dependent increase in the ratio of plasma TRP to competing large neutral amino acids. TRP-rich protein hydrolysate (2 g only) prevented both the decline in wellbeing and increase in fatigue seen over the test session in the control group. This treatment dose resulted in a significant shift in emotional processing towards positive words and reduced negative bias in assessing negative facial expressions. Effects on cognition were small and not statistically reliable and are not reported here. However, there was no evidence for any adverse effects. CONCLUSIONS: Consumption of a low dose of TRP-rich protein hydrolysate may have beneficial effects on emotional function that could promote feelings of wellbeing, possibly conferring resistance to deterioration in mood in healthy subjects or depressive episodes

    High-energy observations of the state transition of the X-ray nova and black hole candidate XTE J1720-318

    Full text link
    We report the results of extensive high-energy observations of the X-ray transient and black hole candidate XTE J1720-318 performed with INTEGRAL, XMM-Newton and RXTE. The source, which underwent an X-ray outburst in 2003 January, was observed in February in a spectral state dominated by a soft component with a weak high-energy tail. The XMM-Newton data provided a high column density Nh of 1.2*e22 cm^{-2} which suggests that the source lies at the Galactic Centre distance. The simultaneous RXTE and INTEGRAL Target of Opportunity observations allowed us to measure the weak and steep tail, typical of a black-hole binary in the so-called High/Soft State. We then followed the evolution of the source outburst over several months using the INTEGRAL Galactic Centre survey observations. The source became active again at the end of March: it showed a clear transition towards a much harder state, and then decayed to a quiescent state after April. In the hard state, the source was detected up to 200 keV with a power law index of 1.9 and a peak luminosity of 7*e36 erg s^{-1} in the 20-200 keV band, for an assumed distance of 8 kpc. We conclude that XTE J1720-318 is indeed a new member of the black hole X-ray novae class which populate our galactic bulge and we discuss its properties in the frame of the spectral models used for transient black hole binaries.Comment: 10 pages, 7 figures, 2 tables, Accepted for publication in Astronomy & Astrophysic

    Gold catalysts supported on ceria doped by rare earth metals for water gas shift reaction: Influence of the preparation method

    Get PDF
    Gold catalysts based on ceria, doped by various RE metals (La, Sm, Gd, Yb, Y) were studied. The influence of the preparation methods on structure, properties and catalytic activity in the WGS reaction was investigated. The catalysts' supports were prepared using two different methods: co-precipitation (CP) and mechanochemical activation (MA). The catalysts were tested in a wide temperature interval without and after reactivation. All samples were characterized using a combination of X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), Raman spectroscopy (RS) and X-ray photoelectron spectroscopy (XPS) and TPR. It was found that the catalytic activity of MA catalysts is higher than CP ones. The gold catalysts based on ceria doped by Yb and Sm exhibited the highest activity. After reactivation in air the MA samples almost kept the WGS activity same, while the CP catalysts increased it. The catalysts of a single- and double-phase structure are formed as a result of CP and MA preparation, respectively. There are no big differences in the gold particles size (2-3 nm) depending on dopants and on the preparation techniques. The RS spectra analysis indicates that most probably the oxygen vacancies are adjacent to Me3+ dopant and the ceria structure seems to be better ordered than in the case of alumina as a dopant. There is no distinct correlation between reducibility and WGS activity. The XPS analysis disclose positively charged gold particles in addition to metallic gold within a surface region of fresh samples and only metallic gold on the samples after catalytic processing. There is no simple correlation between the concentration of Ce3+ in the samples and their WGS activity. © 2009 Elsevier B.V. All rights reserved
    • 

    corecore