809 research outputs found

    CDK4 Inhibitors Thwart Immunity by Inhibiting Phospho-RB-NF-kB Complexes

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    PD-L1 plays a central role in immune recognition of cancer cells. In this issue of Molecular Cell, Jin et al. (2019) report that a phosphorylated retinoblastoma protein contacts the DNA-binding domain of p65 NF-kB, thereby blocking transcription of PD-L1

    Genomic plasticity and rapid host switching can promote the evolution of generalism : a case study in the zoonotic pathogen Campylobacter

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    This work was supported by the Biotechnology and Biological Sciences Research Council (BBSRC) grant BB/I02464X/1, the Medical Research Council (MRC) grants MR/M501608/1 and MR/L015080/1, and the Wellcome Trust grant 088786/C/09/Z. GM was supported by a NISCHR Health Research Fellowship (HF-14–13).Peer reviewedPublisher PD

    Neptunium Reactivity During Co-Precipitation and Oxidation of Fe(II)/Fe(III) (Oxyhydr)oxides

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    Fe(II) bearing iron (oxyhydr)oxides were directly co-precipitated with Np(V)O2+ under anaerobic conditions to form Np doped magnetite and green rust. These environmentally relevant mineral phases were then characterised using geochemical and spectroscopic analyses. The Np doped mineral phases were then oxidised in air over 224 days with solution chemistry and end-point oxidation solid samples collected for further characterisation. Analysis using chemical extractions and X-ray absorption spectroscopy (XAS) techniques confirmed that Np(V) was initially reduced to Np(IV) during co-precipitation of both magnetite and green rust. Extended X-Ray Absorption Fine Structure (EXAFS) modelling suggested the Np(IV) formed a bidentate binuclear sorption complex to both minerals. Furthermore, following oxidation in air over several months, the sorbed Np(IV) was partially oxidised to Np(V), but very little remobilisation to solution occurred during oxidation. Here, linear combination fitting of the X-Ray Absorption Near Edge Structure (XANES) for the end-point oxidation samples for both mineral phases suggested approximately 50% oxidation to Np(V) had occurred over 7 months of oxidation in air. Both the reduction of Np(V) to Np(IV) and inner sphere sorption in association with iron (oxyhydr)oxides, and the strong retention of Np(IV) and Np(V) species with these phases under robust oxidation conditions, have important implications in understanding the mobility of neptunium in a range of engineered and natural environments

    Neptunium Reactivity During Co-Precipitation and Oxidation of Fe(II)/Fe(III) (Oxyhydr)oxides

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    Fe(II) bearing iron (oxyhydr)oxides were directly co-precipitated with Np(V)O2+ under anaerobic conditions to form Np doped magnetite and green rust. These environmentally relevant mineral phases were then characterised using geochemical and spectroscopic analyses. The Np doped mineral phases were then oxidised in air over 224 days with solution chemistry and end-point oxidation solid samples collected for further characterisation. Analysis using chemical extractions and X-ray absorption spectroscopy (XAS) techniques confirmed that Np(V) was initially reduced to Np(IV) during co-precipitation of both magnetite and green rust. Extended X-Ray Absorption Fine Structure (EXAFS) modelling suggested the Np(IV) formed a bidentate binuclear sorption complex to both minerals. Furthermore, following oxidation in air over several months, the sorbed Np(IV) was partially oxidised to Np(V), but very little remobilisation to solution occurred during oxidation. Here, linear combination fitting of the X-Ray Absorption Near Edge Structure (XANES) for the end-point oxidation samples for both mineral phases suggested approximately 50% oxidation to Np(V) had occurred over 7 months of oxidation in air. Both the reduction of Np(V) to Np(IV) and inner sphere sorption in association with iron (oxyhydr)oxides, and the strong retention of Np(IV) and Np(V) species with these phases under robust oxidation conditions, have important implications in understanding the mobility of neptunium in a range of engineered and natural environments

    Controls on the fate and speciation of Np(V) during iron (oxyhydr)oxide crystallization

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    The speciation and fate of neptunium as Np(V)O2+ during the crystallization of ferrihydrite to hematite and goethite was explored in a range of systems. Adsorption of NpO2+ to iron(III) (oxyhydr)oxide phases was reversible and, for ferrihydrite, occurred through the formation of mononuclear bidentate surface complexes. By contrast, chemical extractions and X-ray absorption spectroscopy (XAS) analyses showed the incorporation of Np(V) into the structure of hematite during its crystallization from ferrihydrite (pH 10.5). This occurred through direct replacement of octahedrally coordinated Fe(III) by Np(V) in neptunate-like coordination. Subsequent analyses on mixed goethite and hematite crystallization products (pH 9.5 and 11) showed that Np(V) was incorporated during crystallization. Conversely, there was limited evidence for Np(V) incorporation during goethite crystallization at the extreme pH of 13.3. This is likely due to the formation of a Np(V) hydroxide precipitate preventing incorporation into the goethite particles. Overall these data highlight the complex behavior of Np(V) during the crystallization of iron(III) (oxyhydr)oxides, and demonstrate clear evidence for neptunium incorporation into environmentally important mineral phases. This extends our knowledge of the range of geochemical conditions under which there is potential for long-term immobilization of radiotoxic Np in natural and engineered environments

    Overview of the spectrometer optical fiber feed for the Habitable-zone Planet Finder

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    The Habitable-zone Planet Finder (HPF) is a highly stabilized fiber fed precision radial velocity (RV) spectrograph working in the Near Infrared (NIR): 810 - 1280 nm . In this paper we present an overview of the preparation of the optical fibers for HPF. The entire fiber train from the telescope focus down to the cryostat is detailed. We also discuss the fiber polishing, splicing and its integration into the instrument using a fused silica puck. HPF was designed to be able to operate in two modes, High Resolution (HR- the only mode mode currently commissioned) and High Efficiency (HE). We discuss these fiber heads and the procedure we adopted to attach the slit on to the HR fibers.Comment: Presented at 2018 SPIE Astronomical Telescopes + Instrumentation, Austin, Texas, USA. 18 pages, 25 figures, and 2 table

    A study of adverse reaction algorithms in a drug surveillance program

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110093/1/cptclpt1985156.pd

    Incorporation and retention of 99-Tc(IV) in magnetite under high pH conditions

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    Technetium incorporation into magnetite and its behavior during subsequent oxidation has been investigated at high pH to determine the technetium retention mechanism(s) on formation and oxidative perturbation of magnetite in systems relevant to radioactive waste disposal. Ferrihydrite was exposed to Tc(VII)(aq) containing cement leachates (pH 10.5-13.1), and crystallization of magnetite was induced via addition of Fe(II)aq. A combination of X-ray diffraction (XRD), chemical extraction, and X-ray absorption spectroscopy (XAS) techniques provided direct evidence that Tc(VII) was reduced and incorporated into the magnetite structure. Subsequent air oxidation of the magnetite particles for up to 152 days resulted in only limited remobilization of the incorporated Tc(IV). Analysis of both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) data indicated that the Tc(IV) was predominantly incorporated into the magnetite octahedral site in all systems studied. On reoxidation in air, the incorporated Tc(IV) was recalcitrant to oxidative dissolution with less than 40% remobilization to solution despite significant oxidation of the magnetite to maghemite/goethite: All solid associated Tc remained as Tc(IV). The results of this study provide the first direct evidence for significant Tc(IV) incorporation into the magnetite structure and confirm that magnetite incorporated Tc(IV) is recalcitrant to oxidative dissolution. Immobilization of Tc(VII) by reduction and incorporation into magnetite at high pH and with significant stability upon reoxidation has clear and important implications for limiting technetium migration under conditions where magnetite is formed including in geological disposal of radioactive wastes

    Trends in the medical management of patients with heart failure

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    BACKGROUND: Despite the availability of effective therapies, heart failure (HF) remains a highly prevalent disease and the leading cause of hospitalizations in the U.S. Few data are available, however, describing changing trends in the use of various cardiac medications to treat patients with HF and factors associated with treatment. The objectives of this population-based study were to examine decade-long trends (1995 - 2004) in the use of several cardiac medications in patients hospitalized with acute decompensated heart failure (ADHF) and factors associated with evidence-based treatment. METHODS: We reviewed the medical records of 9,748 residents of the Worcester, MA, metropolitan area who were hospitalized with ADHF at all 11 central Massachusetts medical centers in 1995, 2000, 2002, and 2004. RESULTS: Between 1995 and 2004, respectively, the prescription upon hospital discharge of beta-blockers (23%; 67%), angiotensin pathway inhibitors (47%; 55%), statins (5%; 43%), and aspirin (35%; 51%) increased markedly, while the use of digoxin (51%; 29%), nitrates (46%; 24%), and calcium channel blockers (33%; 22%) declined significantly; nearly all patients received diuretics. Patients in the earliest study year, those with a history of obstructive pulmonary disease or anemia, incident HF, non-specific symptoms, and women were less likely to receive beta blockers and angiotensin pathway inhibitors than respective comparison groups. In 2004, 82% of patients were discharged on at least one of these recommended agents; however, only 41% were discharged on medications from both recommended classes. CONCLUSIONS: Our data suggest that opportunities exist to further improve the use of HF therapeutics
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