5 research outputs found
Revisiting X-ray-Bright-Optically-Normal-Galaxies with the Chandra Source Catalog
X-ray bright optically normal galaxies (XBONGs) are galaxies with X-ray
luminosities consistent with those of active galactic nuclei (AGNs) but no
evidence of AGN optical emission lines. Crossmatching the Chandra Source
Catalog version 2 (CSC2) with the Sloan Digital Sky Survey (SDSS) sample of
spectroscopically classified galaxies, we have identified 817 XBONG candidates
with LX > 1042 erg s-1 and X-ray to optical flux ratio FXO > 0.1. Comparisons
with WISE colors and NIR, optical, UV, and radio luminosities show that the
loci of XBONGs are in-between those of control samples of normal galaxies and
quasars and are consistent with low-luminosity quasars. We find that 43% of the
XBONG sample have X-ray colors suggesting NH > 1022 cm-2, double the fraction
in the QSO sample, suggesting that a large fraction of XBONG are highly
obscured AGNs. However, ~50% of the XBONGs are not obscured and have X-ray
colors harder than those of normal galaxies. Some of these XBONGs have
spatially extended X-ray emission. These characteristics suggest that they may
be unidentified galaxy groups and clusters. Using the X-ray luminosity
functions of QSOs and galaxies/groups/clusters, we estimate the approximate
fraction of extended XBONGs to be < 20%. We also assess the approximate
fraction of XBONGs whose AGN signatures are diluted by stellar light of host
galaxies to be ~30%, based on their redshift and deviation from the
extrapolation of the QSO LX-Lr relation.Comment: Submitted ApJ. 29 pages, 17 figure
The Chandra Source Catalog Normal Galaxy Sample
We present an extensive and well-characterized Chandra X-ray Galaxy Catalog
(CGC) of 8557 galaxy candidates in the redshift range z ~ 0.04 - 0.7, optical
luminosity 1010 - 1011 Lro, and X-ray luminosity (0.5-7 keV) LX = 2x1040 -
2x1043 erg s-1. We estimate ~5% false match fraction and contamination by QSOs.
The CGC was extracted from the Chandra Source Catalog version 2 (CSC2) by
cross-correlating with optical and IR all-sky survey data, including SDSS,
PanSTARRS, DESI Legacy, and WISE. Our selection makes use of two main criteria
that we have tested on the subsample with optical spectroscopical
identification. (1) A joint selection based on X-ray luminosity (LX) and X-ray
to optical flux ratio (FXO), which recovers 63% of the spectroscopically
classified galaxies with a small contamination fraction (7%), a significant
improvement over methods using LX or FXO alone (< 50% recovery). (2) A joint
W1-W2 (W12) WISE color and LX selection that proves effective in excluding QSOs
and improves our selection by recovering 72% of the spectroscopically
classified galaxies and reducing the contamination fraction (4%). Of the CGC,
24% was selected by means of optical spectroscopy; 30% on the basis of LX, FXO,
and W12; and 46% by using either the LX-FXO or the LX-W12 selection criteria.
We have individually examined the data for galaxies with z < 0.1, which may
include more than one CSC2 X-ray source, leading to the exclusion of 110 local
galaxies. Our catalog also includes near-IR and UV data and galaxy
morphological types.Comment: submitted ApJS, 35 pages, 11 figure
Extremely bright x-ray pulsar breaks all the rules
Swift J0243.6+6124 is the first known ultraluminous X-ray pulsar in our Galaxy. This system is an interacting X-ray binary, composed of a rapidly spinning and highly magnetized (≈ 1012 G) neutron star accreting material from the disk of its massive Be companion. Be/X-ray binaries are highly variable and prone to frequent X-ray outbursts. The X-ray pulsar of Swift J0243 is ultraluminous, meaning that it emits at luminosities greater than the Eddington limit for a 1.4 Msun neutron star assuming spherical accretion, Ledd = 1.8 × 1038 erg s −1 . The system reached a peak luminosity L\u3e 1039 erg s−1 during its 2017 outburst. This luminosity is about 10× the Eddington limit for a 1.4 Msun neutron star. The Galactic location of this system allows for the study of super-Eddington accretion as an analog of distant ultraluminous X-ray sources.
I used data from the Neil Gehrels Swift X-ray Telescope to investigate the evolution of the spectral and temporal properties of this system. The goal with this dataset was to understand how accretion onto the neutron star varies in and of out of the super-Eddington regime. I searched for characteristic transitions that could reveal changes in the accretion geometry with luminosity. During the super- Eddington outburst of Swift J0243, the spin period dropped by 0.7%, the pulsed fraction nearly doubled, the hardness ratio reached its lowest point, and the pulse shape changed from single-peaked to double-peaked. Such changes may reflect
Positive Patient Postoperative Outcomes with Pharmacotherapy: A Narrative Review including Perioperative-Specialty Pharmacist Interviews
The influence of pharmacotherapy regimens on surgical patient outcomes is increasingly appreciated in the era of enhanced recovery protocols and institutional focus on reducing postoperative complications. Specifics related to medication selection, dosing, frequency of administration, and duration of therapy are evolving to optimize pharmacotherapeutic regimens for many enhanced recovery protocolized elements. This review provides a summary of recent pharmacotherapeutic strategies, including those configured within electronic health record (EHR) applications and functionalities, that are associated with the minimization of the frequency and severity of postoperative complications (POCs), shortened hospital length of stay (LOS), reduced readmission rates, and cost or revenue impacts. Further, it will highlight preventive pharmacotherapy regimens that are correlated with improved patient preparation, especially those related to surgical site infection (SSI), venous thromboembolism (VTE), nausea and vomiting (PONV), postoperative ileus (POI), and emergence delirium (PoD) as well as less commonly encountered POCs such as acute kidney injury (AKI) and atrial fibrillation (AF). The importance of interprofessional collaboration in all periprocedural phases, focusing on medication management through shared responsibilities for drug therapy outcomes, will be emphasized. Finally, examples of collaborative care through shared mental models of drug stewardship and non-medical practice agreements to improve operative throughput, reduce operative stress, and increase patient satisfaction are illustrated
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Efficacy and safety of two neutralising monoclonal antibody therapies, sotrovimab and BRII-196 plus BRII-198, for adults hospitalised with COVID-19 (TICO): a randomised controlled trial
We aimed to assess the efficacy and safety of two neutralising monoclonal antibody therapies (sotrovimab [Vir Biotechnology and GlaxoSmithKline] and BRII-196 plus BRII-198 [Brii Biosciences]) for adults admitted to hospital for COVID-19 (hereafter referred to as hospitalised) with COVID-19.
In this multinational, double-blind, randomised, placebo-controlled, clinical trial (Therapeutics for Inpatients with COVID-19 [TICO]), adults (aged ≥18 years) hospitalised with COVID-19 at 43 hospitals in the USA, Denmark, Switzerland, and Poland were recruited. Patients were eligible if they had laboratory-confirmed SARS-CoV-2 infection and COVID-19 symptoms for up to 12 days. Using a web-based application, participants were randomly assigned (2:1:2:1), stratified by trial site pharmacy, to sotrovimab 500 mg, matching placebo for sotrovimab, BRII-196 1000 mg plus BRII-198 1000 mg, or matching placebo for BRII-196 plus BRII-198, in addition to standard of care. Each study product was administered as a single dose given intravenously over 60 min. The concurrent placebo groups were pooled for analyses. The primary outcome was time to sustained clinical recovery, defined as discharge from the hospital to home and remaining at home for 14 consecutive days, up to day 90 after randomisation. Interim futility analyses were based on two seven-category ordinal outcome scales on day 5 that measured pulmonary status and extrapulmonary complications of COVID-19. The safety outcome was a composite of death, serious adverse events, incident organ failure, and serious coinfection up to day 90 after randomisation. Efficacy and safety outcomes were assessed in the modified intention-to-treat population, defined as all patients randomly assigned to treatment who started the study infusion. This study is registered with ClinicalTrials.gov, NCT04501978.
Between Dec 16, 2020, and March 1, 2021, 546 patients were enrolled and randomly assigned to sotrovimab (n=184), BRII-196 plus BRII-198 (n=183), or placebo (n=179), of whom 536 received part or all of their assigned study drug (sotrovimab n=182, BRII-196 plus BRII-198 n=176, or placebo n=178; median age of 60 years [IQR 50–72], 228 [43%] patients were female and 308 [57%] were male). At this point, enrolment was halted on the basis of the interim futility analysis. At day 5, neither the sotrovimab group nor the BRII-196 plus BRII-198 group had significantly higher odds of more favourable outcomes than the placebo group on either the pulmonary scale (adjusted odds ratio sotrovimab 1·07 [95% CI 0·74–1·56]; BRII-196 plus BRII-198 0·98 [95% CI 0·67–1·43]) or the pulmonary-plus complications scale (sotrovimab 1·08 [0·74–1·58]; BRII-196 plus BRII-198 1·00 [0·68–1·46]). By day 90, sustained clinical recovery was seen in 151 (85%) patients in the placebo group compared with 160 (88%) in the sotrovimab group (adjusted rate ratio 1·12 [95% CI 0·91–1·37]) and 155 (88%) in the BRII-196 plus BRII-198 group (1·08 [0·88–1·32]). The composite safety outcome up to day 90 was met by 48 (27%) patients in the placebo group, 42 (23%) in the sotrovimab group, and 45 (26%) in the BRII-196 plus BRII-198 group. 13 (7%) patients in the placebo group, 14 (8%) in the sotrovimab group, and 15 (9%) in the BRII-196 plus BRII-198 group died up to day 90.
Neither sotrovimab nor BRII-196 plus BRII-198 showed efficacy for improving clinical outcomes among adults hospitalised with COVID-19.
US National Institutes of Health and Operation Warp Spee