248 research outputs found
Acceptability, feasibility and cost of point of care testing for sexually transmitted infections among South African adolescents where syndromic management is standard of care
BACKGROUND: Young people (YP) in southern Africa are at substantial risk of HIV and sexually transmitted infections (STIs). Despite the epidemiological and biological link between STIs and HIV transmission and acquisition, infections such as Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) remain widely undiagnosed. Syndromic STI management is the standard of care in low- and middle-income countries (LMICs) despite a high prevalence of asymptomatic infections. We conducted an observational study to explore the acceptability, feasibility, and cost of a STI test-and-treat service for YP in Cape Town. METHODS: YP attending a mobile clinic (MC) and a youth centre clinic (YC) were offered STI screening. Urine testing for CT and NG using a 90-min molecular point-of-care (POC) test on the GeneXpert platform was conducted and treatment provided. Data were collated on demographics, sexual behaviour, presence of symptoms, uptake of same-day treatment, prevalence of CT/NG, and service acceptability. RESULTS: Three hundred sixty six participants were enrolled (median age 20, 83% female).57% (209/366) of participants tested positive for either CT (126/366, 34%) or NG (57/366, 16%) or co-infection (26/366, 7%). Clinical symptoms were a poor predictor of GeneXpert diagnosed CT or NG, with a sensitivity of 46.8% and 54.0% for CT and NG respectively. Although half of participants initially chose to receive same day results and treatment, only a third waited for results on the day. The majority of participants (91%) rated the service highly via a post-visit acceptability questionnaire. CONCLUSION: Curable STIs are highly prevalent in this population. STI screening using POC testing was feasible and acceptability was high. The study provides further impetus for moving policy beyond syndromic management of STIs in South Africa
The use of various organic solvents to tailor the properties of Ibuprofen-glucosamine HCl solid dispersions
A fast release dosage form is desirable to improve the absorption of poorly water soluble drugs. Ibuprofen (IBU) is a BCS class II drug that exhibits poor dissolution rate in the gastrointestinal (GI) tract. The aim of the present study is to use various organic solvents to prepare solid dispersions of IBU in the presence of glucosamine HCl (GL), which acts as a carrier to enhance the dissolution of ibuprofen. Different ratios of ibuprofen and glucosamine were dissolved in various organic solvents to obtain the solid dispersions of ibuprofen-glucosamine mixtures. The physic-chemical/solid state analysis of the samples investigated using SEM, DSC, FT-IR and XRPD, particle size analysis and in vitro dissolution studies showed that the type of solvent has a big influence on the dissolution. Ibuprofen-glucosamine solid dispersions obtained from acetone produced better dissolution compared to that of other organic solvents. The effect of water in binary mixtures of acetone or ethanol was also investigated and the results showed that when the ratio of acetone to water was 75:25, the highest dissolution was obtained. Solid state analysis ruled out any chemical interaction between the dug and carrier even in the presence of various organic solvents which indicates a good stability of the solid dispersions to enhance the dissolution rate of ibuprofen. It was also investigated via XRPD analysis that the ibuprofen retained its crystallinity without any adverse effect on the dissolution rates
Measurement of the Atmospheric Spectrum with IceCube
We present a measurement of the atmospheric spectrum at energies
between 0.1 TeV and 100 TeV using data from the first year of the complete
IceCube detector. Atmospheric originate mainly from the decays of kaons
produced in cosmic-ray air showers. This analysis selects 1078 fully contained
events in 332 days of livetime, then identifies those consistent with particle
showers. A likelihood analysis with improved event selection extends our
previous measurement of the conventional fluxes to higher energies. The
data constrain the conventional flux to be times a
baseline prediction from a Honda's calculation, including the knee of the
cosmic-ray spectrum. A fit to the kaon contribution () to the neutrino
flux finds a kaon component that is times the baseline
value. The fitted/measured prompt neutrino flux from charmed hadron decays
strongly depends on the assumed astrophysical flux and shape. If the
astrophysical component follows a power law, the result for the prompt flux is
times a calculated flux based on the work by Enberg, Reno
and Sarcevic.Comment: PRD accepted versio
The IceCube Neutrino Observatory - Contributions to ICRC 2015 Part II: Atmospheric and Astrophysical Diffuse Neutrino Searches of All Flavors
Papers on atmospheric and astrophysical diffuse neutrino searches of all
flavors submitted to the 34th International Cosmic Ray Conference (ICRC 2015,
The Hague) by the IceCube Collaboration.Comment: 66 pages, 36 figures, Papers submitted to the 34th International
Cosmic Ray Conference, The Hague 2015, v2 has a corrected author lis
A combined maximum-likelihood analysis of the high-energy astrophysical neutrino flux measured with IceCube
Evidence for an extraterrestrial flux of high-energy neutrinos has now been
found in multiple searches with the IceCube detector. The first solid evidence
was provided by a search for neutrino events with deposited energies
TeV and interaction vertices inside the instrumented volume. Recent
analyses suggest that the extraterrestrial flux extends to lower energies and
is also visible with throughgoing, -induced tracks from the Northern
hemisphere. Here, we combine the results from six different IceCube searches
for astrophysical neutrinos in a maximum-likelihood analysis. The combined
event sample features high-statistics samples of shower-like and track-like
events. The data are fit in up to three observables: energy, zenith angle and
event topology. Assuming the astrophysical neutrino flux to be isotropic and to
consist of equal flavors at Earth, the all-flavor spectrum with neutrino
energies between 25 TeV and 2.8 PeV is well described by an unbroken power law
with best-fit spectral index and a flux at 100 TeV of
.
Under the same assumptions, an unbroken power law with index is disfavored
with a significance of 3.8 () with respect to the best
fit. This significance is reduced to 2.1 () if instead we
compare the best fit to a spectrum with index that has an exponential
cut-off at high energies. Allowing the electron neutrino flux to deviate from
the other two flavors, we find a fraction of at Earth.
The sole production of electron neutrinos, which would be characteristic of
neutron-decay dominated sources, is rejected with a significance of 3.6
().Comment: 16 pages, 10 figures; accepted for publication in The Astrophysical
Journal; updated one referenc
The IceCube Neutrino Observatory - Contributions to ICRC 2015 Part III: Cosmic Rays
Papers on cosmic rays submitted to the 34th International Cosmic Ray
Conference (ICRC 2015, The Hague) by the IceCube Collaboration.Comment: 83 pages, 52 figues, Papers submitted to the 34th International
Cosmic Ray Conference, The Hague 2015, v2 has a corrected author lis
Characterization of the Atmospheric Muon Flux in IceCube
Muons produced in atmospheric cosmic ray showers account for the by far
dominant part of the event yield in large-volume underground particle
detectors. The IceCube detector, with an instrumented volume of about a cubic
kilometer, has the potential to conduct unique investigations on atmospheric
muons by exploiting the large collection area and the possibility to track
particles over a long distance. Through detailed reconstruction of energy
deposition along the tracks, the characteristics of muon bundles can be
quantified, and individual particles of exceptionally high energy identified.
The data can then be used to constrain the cosmic ray primary flux and the
contribution to atmospheric lepton fluxes from prompt decays of short-lived
hadrons.
In this paper, techniques for the extraction of physical measurements from
atmospheric muon events are described and first results are presented. The
multiplicity spectrum of TeV muons in cosmic ray air showers for primaries in
the energy range from the knee to the ankle is derived and found to be
consistent with recent results from surface detectors. The single muon energy
spectrum is determined up to PeV energies and shows a clear indication for the
emergence of a distinct spectral component from prompt decays of short-lived
hadrons. The magnitude of the prompt flux, which should include a substantial
contribution from light vector meson di-muon decays, is consistent with current
theoretical predictions.Comment: 36 pages, 39 figure
The search for transient astrophysical neutrino emission with IceCube-DeepCore
We present the results of a search for astrophysical sources of brief transient neutrino emission using IceCube and DeepCore data acquired between 2012 May 15 and 2013 April 30. While the search methods employed in this analysis are similar to those used in previous IceCube point source searches, the data set being examined consists of a sample of predominantly sub-TeV muon-neutrinos from the Northern Sky (-5 degrees < delta < 90 degrees) obtained through a novel event selection method. This search represents a first attempt by IceCube to identify astrophysical neutrino sources in this relatively unexplored energy range. The reconstructed direction and time of arrival of neutrino events are used to search for any significant self-correlation in the data set. The data revealed no significant source of transient neutrino emission. This result has been used to construct limits at timescales ranging from roughly 1 s to 10 days for generic soft-spectra transients. We also present limits on a specific model of neutrino emission from soft jets in core-collapse supernovae
Search for Dark Matter Annihilation in the Galactic Center with IceCube-79
The Milky Way is expected to be embedded in a halo of dark matter particles,
with the highest density in the central region, and decreasing density with the
halo-centric radius. Dark matter might be indirectly detectable at Earth
through a flux of stable particles generated in dark matter annihilations and
peaked in the direction of the Galactic Center. We present a search for an
excess flux of muon (anti-) neutrinos from dark matter annihilation in the
Galactic Center using the cubic-kilometer-sized IceCube neutrino detector at
the South Pole. There, the Galactic Center is always seen above the horizon.
Thus, new and dedicated veto techniques against atmospheric muons are required
to make the southern hemisphere accessible for IceCube. We used 319.7 live-days
of data from IceCube operating in its 79-string configuration during 2010 and
2011. No neutrino excess was found and the final result is compatible with the
background. We present upper limits on the self-annihilation cross-section,
\left, for WIMP masses ranging from 30 GeV up to
10 TeV, assuming cuspy (NFW) and flat-cored (Burkert) dark matter halo
profiles, reaching down to cm s, and
cm s for the
channel, respectively.Comment: 14 pages, 9 figures, Submitted to EPJ-C, added references, extended
limit overvie
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