Background-Community acquired pneumonia remains an important cause ofhospital admission and carries an appreciable mortality. Criteria for the assessment of severity during admission have been developed by the British Thoracic Society (BTS). A study was performed to determine the sensitivity and specificity of a
Complexation of cationic fluorosurfactants to well-defined acrylic acid plasma polymer surfaces gives rise to oleophobic/hydrophilic behavior. This is in marked contrast to the usual oleophobic/hydrophobic liquid repellent attributes of conventional polyelectrolyte−fluorosurfactant complexes formed by solution-phase synthesis.
Recent all-sky surveys have led to the discovery of new types of transients. These include stars disrupted by the central supermassive black hole, and supernovae that are 10–100 times more energetic than typical ones. However, the nature of even more energetic transients that apparently occur in the innermost regions of their host galaxies is hotly debated1,2,3. Here we report the discovery of the most energetic of these to date: PS1-10adi, with a total radiated energy of ~2.3 × 1052 erg. The slow evolution of its light curve and persistently narrow spectral lines over ∼ 3 yr are inconsistent with known types of recurring black hole variability. The observed properties imply powering by shock interaction between expanding material and large quantities of surrounding dense matter. Plausible sources of this expanding material are a star that has been tidally disrupted by the central black hole, or a supernova. Both could satisfy the energy budget. For the former, we would be forced to invoke a new and hitherto unseen variant of a tidally disrupted star, while a supernova origin relies principally on environmental effects resulting from its nuclear location. Remarkably, we also discover that PS1-10adi is not an isolated case. We therefore surmise that this new population of transients has previously been overlooked due to incorrect association with underlying central black hole activity
We present a detailed characterization of the X‐ray spectral properties of 761 type 1 active galactic nuclei (AGN), selected from a cross‐correlation of the SDSS DR5 quasar catalogue and the incremental version of the second XMM–Newton serendipitous X‐ray source catalogue 2XMMi‐DR2. The X‐ray spectrum of each source has been fitted with models based on a simple power law to which additional cold absorption and/or soft‐excess features have been added if an F‐test at 99 per cent significance required them. The distribution of best‐fitting photon indices, Γ, has been fitted with a Gaussian with mean 〈Γ〉= 1.99 ± 0.01 and dispersion σ〈Γ〉= 0.30 ± 0.01; however, this does not provide a good representation of the distribution due to sources with very flat or steep Γ values. A highly significant trend for decreasing Γ values with increasing 2–10 keV luminosity, LX, has been seen but only a weak trend with redshift has been found. Intrinsic cold absorption has been detected in ∼4 per cent of the sample and soft‐excess emission has been detected in ∼8 per cent. These values are lower limits due to the detectability being limited by the quality of the spectra and we suggest that the intrinsic values may be as high as ∼25 and ∼80 per cent, respectively. The levels of rest‐frame absorption are higher than expected for type 1 objects (NH= 1021–1023 cm−2) and the fraction of absorbed sources and the NH values were not seen to vary with LX or z. The average blackbody temperature used to model the soft excesses is 〈kT〉= 0.17 ± 0.09 keV. This temperature has been found to correlate with LX but not the blackbody luminosity or the black hole mass which do correlate with each other. A strong correlation has been found between the luminosities in the blackbody and power‐law components, suggesting that a similar fraction is reprocessed from the blackbody to the power‐law component for the entire luminosity range of objects. A positive correlation between Γ and the X‐ray derived Eddington ratio has been found for the sources whose mass was determined using the Hβ line, but a negative correlation has been found where the C iv line was used. No correlation has been found where the Mg ii line was used. No significant correlations have been found between the blackbody temperature, luminosity or black hole mass with Eddington ratio, despite a link between the power law and blackbody production being indicated. The sample includes 552 confirmed radio‐quiet quasars (RQQ) and 75 confirmed radio‐loud quasars (RLQ). The RLQ have been found to have higher LX values than their RQQ counterparts, suggesting an additional X‐ray component, perhaps related to a jet, is present in these sources. This component may also be the cause of the flatter Γ values seen in RLQ.
These findings have implications for both standard treatment protocols and vaccine strategies. The high rate of coinfection may make it difficult to develop simple clinical predictors of bacterial infection. In the setting of a developed country with efficient patient evacuation services, management algorithms that focus on disease severity and need for hospital referral will be most useful to health staff in remote communities. Pneumococcal conjugate vaccines will be required to reduce the high attack rate of pneumococcal disease.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.