695 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

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    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

    Dispersion and release of embelin from electrospun biodegradable, polymeric, membranes

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    In this work, microfiber meshes containing embelin, a poorly water-soluble bioactive agent, were prepared by solubilizing embelin in a biodegradable and biocompatible polymer matrix of poly(ε-caprolactone) (PCL). Plain or drug-loaded, highly porous, fibrous membranes with a high area-to-volume ratio were obtained by electrospinning. Non-woven microfibrous meshes were formed by uniform bead-free fibers with a mean diameter of 1.2 μm. Non-porous films were obtained by solution casting, and were used for comparison. The drug-loading content of the prepared systems was appropriate for topical applications. The thermal properties revealed that the crystallinity of embelin significantly decreased, the drug having almost completely dissolved in the PCL fibers. The in situ bioavailability of embelin, an antimycotic agent, is an important aspect to consider in topical drug applications. The drug-loaded systems presented different contact areas with the biological environment. When comparing the ability to expose embelin with the biological environment of the prepared systems, drug-loaded fibrous scaffolds showed a higher bioavailability of the bioactive agent because of an increase by 86% in the area-to-volume ratio, providing an effective area per unit mass that was 5.8-fold higher than that of the film. For the meshes, 90% embelin release was observed after 12h of exposure to phosphate-buffered saline, whereas for the films a comparable level of release occurred only after 72h.Fil: Cortez Tornello, Pablo Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Feresin, Gabriela Egly. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Tapia, Alejandro. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Veiga, Itiara G.. Universidade Estadual de Campinas; BrasilFil: Moraes, Ângela M.. Universidade Estadual de Campinas; BrasilFil: Abraham, Gustavo Abel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; ArgentinaFil: Cuadrado, Teresita Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentin

    A combined maximum-likelihood analysis of the high-energy astrophysical neutrino flux measured with IceCube

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    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 30\gtrsim30 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, νμ\nu_\mu-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 2.50±0.09-2.50\pm0.09 and a flux at 100 TeV of (6.71.2+1.1)1018GeV1s1sr1cm2\left(6.7_{-1.2}^{+1.1}\right)\cdot10^{-18}\,\mathrm{GeV}^{-1}\mathrm{s}^{-1}\mathrm{sr}^{-1}\mathrm{cm}^{-2}. Under the same assumptions, an unbroken power law with index 2-2 is disfavored with a significance of 3.8 σ\sigma (p=0.0066%p=0.0066\%) with respect to the best fit. This significance is reduced to 2.1 σ\sigma (p=1.7%p=1.7\%) if instead we compare the best fit to a spectrum with index 2-2 that has an exponential cut-off at high energies. Allowing the electron neutrino flux to deviate from the other two flavors, we find a νe\nu_e fraction of 0.18±0.110.18\pm0.11 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 σ\sigma (p=0.014%p=0.014\%).Comment: 16 pages, 10 figures; accepted for publication in The Astrophysical Journal; updated one referenc

    Measurement of the Atmospheric νe\nu_e Spectrum with IceCube

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    We present a measurement of the atmospheric νe\nu_e spectrum at energies between 0.1 TeV and 100 TeV using data from the first year of the complete IceCube detector. Atmospheric νe\nu_e 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 νe\nu_e fluxes to higher energies. The data constrain the conventional νe\nu_e flux to be 1.30.3+0.41.3^{+0.4}_{-0.3} times a baseline prediction from a Honda's calculation, including the knee of the cosmic-ray spectrum. A fit to the kaon contribution (ξ\xi) to the neutrino flux finds a kaon component that is ξ=1.30.4+0.5\xi =1.3^{+0.5}_{-0.4} 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 0.00.0+3.00.0^{+3.0}_{-0.0} 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

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    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

    Characterization of the Atmospheric Muon Flux in IceCube

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    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

    Search for Dark Matter Annihilation in the Galactic Center with IceCube-79

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    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 41024\simeq 4 \cdot 10^{-24} cm3^3 s1^{-1}, and 2.61023\simeq 2.6 \cdot 10^{-23} cm3^3 s1^{-1} for the νν\nu\overline{\nu} channel, respectively.Comment: 14 pages, 9 figures, Submitted to EPJ-C, added references, extended limit overvie

    The IceCube Neutrino Observatory - Contributions to ICRC 2015 Part III: Cosmic Rays

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    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
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