X-Ray Spectroscopy of Stars

(abridged) Non-degenerate stars of essentially all spectral classes are soft X-ray sources. Low-mass stars on the cooler part of the main sequence and their pre-main sequence predecessors define the dominant stellar population in the galaxy by number. Their X-ray spectra are reminiscent, in the broadest sense, of X-ray spectra from the solar corona. X-ray emission from cool stars is indeed ascribed to magnetically trapped hot gas analogous to the solar coronal plasma. Coronal structure, its thermal stratification and geometric extent can be interpreted based on various spectral diagnostics. New features have been identified in pre-main sequence stars; some of these may be related to accretion shocks on the stellar surface, fluorescence on circumstellar disks due to X-ray irradiation, or shock heating in stellar outflows. Massive, hot stars clearly dominate the interaction with the galactic interstellar medium: they are the main sources of ionizing radiation, mechanical energy and chemical enrichment in galaxies. High-energy emission permits to probe some of the most important processes at work in these stars, and put constraints on their most peculiar feature: the stellar wind. Here, we review recent advances in our understanding of cool and hot stars through the study of X-ray spectra, in particular high-resolution spectra now available from XMM-Newton and Chandra. We address issues related to coronal structure, flares, the composition of coronal plasma, X-ray production in accretion streams and outflows, X-rays from single OB-type stars, massive binaries, magnetic hot objects and evolved WR stars.Comment: accepted for Astron. Astrophys. Rev., 98 journal pages, 30 figures (partly multiple); some corrections made after proof stag

Anticholinergic drug burden tools/scales and adverse outcomes in different clinical settings: a systematic review of reviews

Background: Cumulative anticholinergic exposure (anticholinergic burden) has been linked to a number of adverse outcomes. To conduct research in this area, an agreed approach to describing anticholinergic burden is needed. Objective: This review set out to identify anticholinergic burden scales, to describe their rationale, the settings in which they have been used and the outcomes associated with them. Methods: A search was performed using the Healthcare Databases Advanced Search of MEDLINE, EMBASE, Cochrane, CINAHL and PsycINFO from inception to October 2016 to identify systematic reviews describing anticholinergic burden scales or tools. Abstracts and titles were reviewed to determine eligibility for review with eligible articles read in full. The final selection of reviews was critically appraised using the ROBIS tool and pre-defined data were extracted; the primary data of interest were the anticholinergic burden scales or tools used. Results: Five reviews were identified for analysis containing a total of 62 original articles. Eighteen anticholinergic burden scales or tools were identified with variation in their derivation, content and how they quantified the anticholinergic activity of medications. The Drug Burden Index was the most commonly used scale or tool in community and database studies, while the Anticholinergic Risk Scale was used more frequently in care homes and hospital settings. The association between anticholinergic burden and clinical outcomes varied by index and study. Falls and hospitalisation were consistently found to be associated with anticholinergic burden. Mortality, delirium, physical function and cognition were not consistently associated. Conclusions: Anticholinergic burden scales vary in their rationale, use and association with outcomes. This review showed that the concept of anticholinergic burden has been variably defined and inconsistently described using a number of indices with different content and scoring. The association between adverse outcomes and anticholinergic burden varies between scores and has not been conclusively established

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

Meeting abstrac

Heterosubtypic Neutralizing Monoclonal Antibodies Cross-Protective against H5N1 and H1N1 Recovered from Human IgM+ Memory B Cells

Background: The hemagglutinin (HA) glycoprotein is the principal target of protective humoral immune responses to influenza virus infections but such antibody responses only provide efficient protection against a narrow spectrum of HA antigenic variants within a given virus subtype. Avian influenza viruses such as H5N1 are currently panzootic and pose a pandemic threat. These viruses are antigenically diverse and protective strategies need to cross protect against diverse viral clades. Furthermore, there are 16 different HA subtypes and no certainty the next pandemic will be caused by an H5 subtype, thus it is important to develop prophylactic and therapeutic interventions that provide heterosubtypic protection. Methods and Findings: Here we describe a panel of 13 monoclonal antibodies (mAbs) recovered from combinatorial display libraries that were constructed from human IgM+ memory B cells of recent (seasonal) influenza vaccinees. The mAbs have broad heterosubtypic neutralizing activity against antigenically diverse H1, H2, H5, H6, H8 and H9 influenza subtypes. Restriction to variable heavy chain gene IGHV1-69 in the high affinity mAb panel was associated with binding to a conserved hydrophobic pocket in the stem domain of HA. The most potent antibody (CR6261) was protective in mice when given before and after lethal H5N1 or H1N1 challenge. Conclusions: The human monoclonal CR6261 described in this study could be developed for use as a broad spectrum agent for prophylaxis or treatment of human or avian influenza infections without prior strain characterization. Moreover, the CR6261 epitope could be applied in targeted vaccine strategies or in the design of novel antivirals. Finally our approach of screening the IgM+ memory repertoire could be applied to identify conserved and functionally relevant targets on other rapidly evolving pathogens

Enzyme production from food wastes using a biorefinery concept

According to Food and Agricultural Organization (FAO), one-third of food produced globally for human consumption (nearly 1.3 billion tonnes) is lost along the food supply chain. In many countries food waste is currently landfilled or incinerated together with other combustible municipal wastes for possible recovery of energy. However, these two options are facing more and more economic and environmental stresses. Due to its organic- and nutrient-rich nature, theoretically food waste can be converted to valuable products (e.g. bio-products such as methane, hydrogen, ethanol, enzymes, organic acids, chemicals and fuels) through various fermentation processes. Such conversion of food waste is potentially more profitable than its conversion to animal feed or transportation fuel. Food waste valorisation has therefore gained interest, with value added bio-products such as methane, hydrogen, ethanol, enzymes, organic acids, chemicals, and fuels. Therefore, the aim of this review is to provide information on the food waste situation with emphasis on Asia–Pacific countries and the state of the art food waste processing technologies to produce enzymes

First Measurement of the Hubble Constant from a Dark Standard Siren using the Dark Energy Survey Galaxies and the LIGO/Virgo Binary-Black-hole Merger GW170814

We present a multi-messenger measurement of the Hubble constant H 0 using the binary–black-hole merger GW170814 as a standard siren, combined with a photometric redshift catalog from the Dark Energy Survey (DES). The luminosity distance is obtained from the gravitational wave signal detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO)/Virgo Collaboration (LVC) on 2017 August 14, and the redshift information is provided by the DES Year 3 data. Black hole mergers such as GW170814 are expected to lack bright electromagnetic emission to uniquely identify their host galaxies and build an object-by-object Hubble diagram. However, they are suitable for a statistical measurement, provided that a galaxy catalog of adequate depth and redshift completion is available. Here we present the first Hubble parameter measurement using a black hole merger. Our analysis results in ${H}_{0}={75}_{-32}^{+40}\,\mathrm{km}\,{{\rm{s}}}^{-1}\,{\mathrm{Mpc}}^{-1}$, which is consistent with both SN Ia and cosmic microwave background measurements of the Hubble constant. The quoted 68% credible region comprises 60% of the uniform prior range [20, 140] km s−1 Mpc−1, and it depends on the assumed prior range. If we take a broader prior of [10, 220] km s−1 Mpc−1, we find {H}_{0 {78}_{-24}^{+96}\,\mathrm{km}\,{{\rm{s}}}^{-1}\,{\mathrm{Mpc}}^{-1} (57% of the prior range). Although a weak constraint on the Hubble constant from a single event is expected using the dark siren method, a multifold increase in the LVC event rate is anticipated in the coming years and combinations of many sirens will lead to improved constraints on H 0

First-principle description of magnonic PdnFem multilayers

Ab-initio calculations are used to determine the parameters that determine magnonic band structure of PdnFem multilayers (n = 2, m <= 8). We obtain the layer-resolved magnetization, the exchange coupling, and the magnetic anisotropy of the Pd-Fe structures. The Fe moment is 3.0 mu(B) close to the Pd layers and 2.2 mu(B) in the middle of the Fe layers. An intriguing but not usually considered aspect is that the elemental Pd is nonmagnetic, similar to Cu spacer layers in other multilayer systems. This leads to a pre-asymptotic ferromagnetic coupling through the Pd (about 40 mJ/m(2)). Furthermore, the Pd acquires a small moment due to spin polarization by neighboring Fe atoms, which translates into magnetic anisotropy. The anisotropies are large, in the range typical for L1(0) structures, which is beneficial for high-frequency applications. (C) 2011 American Institute of Physics. doi:10.1063/1.3556763

Microstructure and properties of hot extruded Cu-1 wt% Al2O3 nano-composites synthesized by various techniques

Cu-1 wt% Al(2)0(3) nano-composites were prepared by three different methods, namely mechanical alloying, combustion synthesis and electrical explosion of wire, in order to investigate the effect of power processing technique on microstructure and ambient properties. The powders produced by these techniques were hydrogen reduced at 500 degrees C and subsequently vacuum encapsulated in copper container followed by consolidation using hot extrusion at 800 C and 600 MPa to nearly full density. As-synthesized composite powders as well as the extruded samples were characterized by scanning electron microscope, X-ray diffraction, transmission electron microscope, thermal conductivity and electrical conductivity. Microhardness and room temperature deformation behavior in compression at a strain rate of 10(-4) s(-1) were measured. The mechanically milled powders, upon consolidation, exhibited a finer grain size of 146 nm and a hardness of 164 HV1.0 compared to that obtained by two other techniques, which ranged between 179-390 nm and 135-156 HV1.0, respectively. The physical and mechanical properties were found to vary with grain size according to the Hall-Petch type relationship, irrespective of the processing technique employed for getting these grain sizes. (C) 2013 Elsevier B.V. All rights reserved

Dynamic strain ageing in fine grained Cu-1 wt%Al2O3 composite processed by two step ball milling and spark plasma sintering

Cu-1 wt%Al2O3 composite powder, prepared by mechanical milling and consolidated by spark plasma sintering to have about 98-99% of theoretical density, were characterized by scanning electron microscope, focused ion beam microscope, X-ray diffraction, nanoindentation and transmission electron microscope. The mechanically milled powders, upon consolidation, exhibited a finer grain size of 2 mu m. Tensile deformation behavior of this composite, at ambient temperature but over the strain rates of 10(-4) s(-1) to 5 x 10(-2) s(-1), exhibited typical manifestations of dynamic strain ageing in the form of serrations and negative strain rate dependence of flow stress. The yield and ultimate tensile strengths, and so also the elongation decrease gradually with increase in strain rate. Such variation was also shown by nanoindentation hardness as a function of loading rate over 1-100 mN/s. The observed results are explained by the dislocation structure evolved from its interaction with Al2O3 dispersoids and impurity atoms like Fe, C and O coming from the powder processing. (C) 2015 Elsevier B.V. All rights reserved