176 research outputs found
Influence of Partial Replacement of Nickel by Nitrogen on Microstructure and Mechanical Properties of Austenitic Stainless Steel
Drive-up INR testing and phone-based consultations service during COVID-19 pandemic in a pharmacist-lead anticoagulation clinic in Qatar: Monitoring, clinical, resource utilization, and patient- oriented outcomes
Background: Coronavirus disease 2019 (COVID-19) pandemic has resulted in unprecedented pressure on healthcare systems and led to widespread utilization of telemedicine or telehealth services. Combined with teleclinics, using drive-up fingerstick International normalized ratio (INR) testing was recommended to decrease exposure risk of anticoagulation patients. Objective: To evaluate the impact of transitioning from clinic-based anticoagulation management services to drive-up and phone-based services during COVID-19 pandemic in Qatar. Methods: The study comprised of two components: a retrospective cohort study of all eligible patients who attended anticoagulation clinic over 1-year period (6Â months before and 6Â months after service transition) and a cross-sectional survey of eligible patients who agreed to provide data about their satisfaction with the new service. Monitoring parameters, clinical outcomes, and resource utilization related to warfarin therapy were compared before and after service transition. Patients' experience was explored through a structured survey. Results: There was no statistically significant difference between clinic-based and phone-based anticoagulation services in mean time and number of visits within therapeutic range (PÂ =.67; PÂ =.06 respectively); mean number of extreme subtherapeutic and supratherapeutic INR values (PÂ =.32 and PÂ =.34, respectively); incidence of thromboembolic complications and warfarin related hospitalization. There was one reported bleeding and one emergency visit (0.9%) in the phone-based group vs none in the clinic-based group. Frequency of INR testing and compliance to attending clinics appointments declined significantly (PÂ =.002; PÂ =.001, respectively). Overall, patients were highly satisfied with the new service. The majority of patients found it better (51.6%) or just as good as the traditional service (44.5%). Patients who preferred the new service were significantly younger than their counterparts (PÂ =.005). Conclusion: The service of drive-up INR testing and phone-based consultations was shown to be comparable to traditional anticoagulation service, a finding that supports maintaining such services as part of the new normal after the pandemic is over
Improving white dwarfs as chronometers with gaia parallaxes and spectroscopic metallicities
White dwarfs (WDs) offer unrealized potential in solving two problems in astrophysics: stellar age accuracy and precision. WD cooling ages can be inferred from surface temperatures and radii, which can be constrained with precision by high-quality photometry and parallaxes. Accurate and precise Gaia parallaxes along with photometric surveys provide information to derive cooling and total ages for vast numbers of WDs. Here we analyze 1372 WDs found in wide binaries with main-sequence (MS) companions and report on the cooling and total age precision attainable in these WD+MS systems. The total age of a WD can be further constrained if its original metallicity is known because the MS lifetime depends on metallicity at fixed mass, yet metallicity is unavailable via spectroscopy of the WD. We show that incorporating spectroscopic metallicity constraints from 38 wide binary MS companions substantially decreases internal uncertainties in WD total ages compared to a uniform constraint. Averaged over the 38 stars in our sample, the total (internal) age uncertainty improves from 21.04% to 16.77% when incorporating the spectroscopic constraint. Higher mass WDs yield better total age precision; for eight WDs with zero-age MS masses â„2.0 Mâ, the mean uncertainty in total ages improves from 8.61% to 4.54% when incorporating spectroscopic metallicities. We find that it is often possible to achieve 5% total age precision for WDs with progenitor masses above 2.0 Mâ if parallaxes with â€1% precision and Pan-STARRS g, r, and i photometry with â€0.01 mag precision are available
The Origins of the Circumgalactic Medium in the FIRE Simulations
We use a particle tracking analysis to study the origins of the
circumgalactic medium (CGM), separating it into (1) accretion from the
intergalactic medium (IGM), (2) wind from the central galaxy, and (3) gas
ejected from other galaxies. Our sample consists of 21 FIRE-2 simulations,
spanning the halo mass range log(Mh/Msun) ~ 10-12 , and we focus on z=0.25 and
z=2. Owing to strong stellar feedback, only ~L* halos retain a baryon mass
>~50% of their cosmic budget. Metals are more efficiently retained by halos,
with a retention fraction >~50%. Across all masses and redshifts analyzed >~60%
of the CGM mass originates as IGM accretion (some of which is associated with
infalling halos). Overall, the second most important contribution is wind from
the central galaxy, though gas ejected or stripped from satellites can
contribute a comparable mass in ~L* halos. Gas can persist in the CGM for
billions of years, resulting in well-mixed halo gas. Sight lines through the
CGM are therefore likely to intersect gas of multiple origins. For low-redshift
~L* halos, cool gas (T<10^4.7 K) is distributed on average preferentially along
the galaxy plane, however with strong halo-to-halo variability. The metallicity
of IGM accretion is systematically lower than the metallicity of winds
(typically by >~1 dex), although CGM and IGM metallicities depend significantly
on the treatment of subgrid metal diffusion. Our results highlight the multiple
physical mechanisms that contribute to the CGM and will inform observational
efforts to develop a cohesive picture.Comment: 23 pages, 22 figures. Minor revisions from previous version. Online
interactive visualizations available at zhafen.github.io/CGM-origins and
zhafen.github.io/CGM-origins-pathline
Understanding Dwarf Galaxies in order to Understand Dark Matter
Much progress has been made in recent years by the galaxy simulation
community in making realistic galaxies, mostly by more accurately capturing the
effects of baryons on the structural evolution of dark matter halos at high
resolutions. This progress has altered theoretical expectations for galaxy
evolution within a Cold Dark Matter (CDM) model, reconciling many earlier
discrepancies between theory and observations. Despite this reconciliation, CDM
may not be an accurate model for our Universe. Much more work must be done to
understand the predictions for galaxy formation within alternative dark matter
models.Comment: Refereed contribution to the Proceedings of the Simons Symposium on
Illuminating Dark Matter, to be published by Springe
Non-contrasted Computed Tomography for the Accurate Measurement of Liver Steatosis in Obese Patients
Amorphous formulations of indomethacin and griseofulvin prepared by electrospinning
Following an array of optimization
experiments, two series of electrospun
polyvinylpyrrolidone (PVP) fibers were prepared. One set of fibers
contained various loadings of indomethacin, known to form stable glasses,
and the other griseofulvin (a poor glass former). Drug loadings of
up to 33% w/w were achieved. Electron microscopy data showed the fibers
largely to comprise smooth and uniform cylinders, with evidence for
solvent droplets in some samples. In all cases, the drug was found
to exist in the amorphous physical state in the fibers on the basis
of X-ray diffraction and differential scanning calorimetry (DSC) measurements.
Modulated temperature DSC showed that the relationship between a formulationâs
glass transition temperature (<i>T</i><sub>g</sub>) and
the drug loading follows the GordonâTaylor equation, but not
the Fox equation. The results of GordonâTaylor analysis indicated
that the drug/polymer interactions were stronger with indomethacin.
The interactions between drug and polymer were explored in more detail
using molecular modeling simulations and again found to be stronger
with indomethacin; the presence of significant intermolecular forces
was further confirmed using IR spectroscopy. The amorphous form of
both drugs was found to be stable after storage of the fibers for
8 months in a desiccator (relative humidity <25%). Finally, the
functional performance of the fibers was studied; in all cases, the
drug-loaded fibers released their drug cargo very rapidly, offering
accelerated dissolution over the pure drug
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