4,083 research outputs found

    Contemporary surgical practice in the management of anal fistula: results from an international survey

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    Background Management of anal fistula (AF) remains challenging with many controversies. The purpose of this study was to explore current surgical practice in the management of AF with a focus on technical variations among surgeons. Methods An online survey was conducted by inviting all surgeons and physicians on the membership directory of European Society of Coloproctology and American Society of Colon and Rectal Surgeons. An invitation was extended to others via social media. The survey had 74 questions exploring diagnostic and surgical techniques. Results In March 2018, 3572 physicians on membership directory were invited to take part in the study 510 of whom (14%) responded to the survey. Of these respondents, 492 (96%) were surgeons. Respondents were mostly colorectal surgeons (84%) at consultant level (84%), age ≥ 40 years (64%), practicing in academic (53%) or teaching (30%) hospitals, from the USA (36%) and Europe (34%). About 80% considered fistulotomy as the gold standard treatment for simple fistulas. Endorectal advancement flap was performed using partial- (42%) or full-thickness (44%) flaps. Up to 38% of surgeons performed ligation of the intersphincteric fistula tract (LIFT) sometimes with technical variations. Geographic and demographic differences were found in both the diagnostic and therapeutic approaches to AF. Declared rates of recurrence and fecal incontinence with these techniques were variable and did not correlate with surgeons’ experience. Only 1–4% of surgeons were confident in performing the most novel sphincter-preserving techniques in patients with Crohn’s disease. Conclusions Profound technical variations exist in surgical management of AF, making it difficult to reproduce and compare treatment outcomes among different centers

    Temperature dependent fluorescence in disordered Frenkel chains: interplay of equilibration and local band-edge level structure

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    We model the optical dynamics in linear Frenkel exciton systems governed by scattering on static disorder and lattice vibrations, and calculate the temperature dependent fluorescence spectrum and lifetime. The fluorescence Stokes shift shows a nonmonotonic behavior with temperature, which derives from the interplay of the local band-edge level structure and thermal equilibration. The model yields excellent fits to experiments performed on linear dye aggregates.Comment: 4 pages, 3 figure

    Determinants of adult vaccination at inner-city health centers: A descriptive study

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    BACKGROUND: Pneumococcal polysaccharide vaccination rates among adults 65 years and older or less than 65 years with high risk medical conditions are still below Healthy People 2010 recommended levels of 90%. This study was designed to: 1) assess self-reported pneumococcal vaccination rates following health center level interventions to increase adult vaccination rates; and 2) determine factors associated with vaccination. METHODS: Tailored interventions to increase immunizations were implemented at two inner-city health centers. We surveyed 375 patients 50 years of age and older. Multivariate logistic regression examines the predictors of 1) self-reported pneumococcal vaccination and 2) combined self-reported influenza and pneumococcal vaccination. Both of these models were stratified by age group (50–64 years and 65 years and older). RESULTS: Pneumococcal vaccination rates were 45% by self-report, 55% by medical record review, 69% for patients 65 years old and older, 32% for patients 50–64 years; they did not differ by race. Receipt of the previous season's influenza vaccine was significantly related to pneumococcal vaccination among both younger and older patients. Receiving both the pneumococcal vaccine and the most recent influenza vaccine compared with receiving neither, among younger patients was related to unemployment, more frequent physician visits, and belief that those who do not receive the flu shot are more susceptible to the flu. For older patients, receipt of both vaccines was related to nonsmoking status, believing that friends/family think the patient should be vaccinated, seeing posters advertising flu shot clinics, and belief that those who do not receive the flu shot are more susceptible to the flu. CONCLUSION: Our findings suggest that improving overall pneumococcal vaccination rates among eligible adults, has the potential to eliminate racial disparities. Interventions delivering vaccination messages specific to older and younger adult groups may be the best strategy for improving adult vaccination rates

    Formation of finite antiferromagnetic clusters and the effect of electronic phase separation in Pr{_0.5}Ca{_0.5}Mn{_0.975}Al{_0.025}O{_3}

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    We report the first experimental evidence of a magnetic phase arising due to the thermal blocking of antiferromagnetic clusters in the weakened charge and orbital ordered system Pr{_0.5}Ca{_0.5}Mn{_0.975}Al{_0.025}O{_3}. The third order susceptibility (\chi_3) is used to differentiate this transition from a spin or cluster glass like freezing mechanism. These clusters are found to be mesoscopic and robust to electronic phase separation which only enriches the antiphase domain walls with holes at the cost of the bulk, without changing the size of these clusters. This implies that Al substitution provides sufficient disorder to quench the length scales of the striped phases.Comment: 4 Post Script Figure

    Influence of polymer excluded volume on the phase behavior of colloid-polymer mixtures

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    We determine the depletion-induced phase-behavior of hard sphere colloids and interacting polymers by large-scale Monte Carlo simulations using very accurate coarse-graining techniques. A comparison with standard Asakura-Oosawa model theories and simulations shows that including excluded volume interactions between polymers leads to qualitative differences in the phase diagrams. These effects become increasingly important for larger relative polymer size. Our simulations results agree quantitatively with recent experiments.Comment: 5 pages, 4 figures submitted to Physical Review Letter

    Search for a 33.9 MeV/c^2 Neutral Particle in Pion Decay

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    The E815 (NuTeV) neutrino experiment has performed a search for a 33.9 MeV/c^2 weakly-interacting neutral particle produced in pion decay. Such a particle may be responsible for an anomaly in the timing distribution of neutrino interactions in the KARMEN experiment. E815 has searched for this particle's decays in an instrumented decay region; no evidence for this particle was found. The search is sensitive to pion branching ratios as low as 10^-13.Comment: 4 pages; 5 figure

    Lorentz- and CPT-violating models for neutrino oscillations

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    A class of calculable global models for neutrino oscillations based on Lorentz and CPT violation is presented. One simple example matches established neutrino data from accelerator, atmospheric, reactor, and solar experiments, using only two degrees of freedom instead of the usual five. A third degree of freedom appears in the model, and it naturally generates the MiniBooNE low-energy anomalies. More involved models in this class can also accommodate the LSND anomaly and neutrino-antineutrino differences of the MINOS type. The models predict some striking signals in various ongoing and future experiments.Comment: 17 pages two-column REVTe

    First Measurement of Monoenergetic Muon Neutrino Charged Current Interactions

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    We report the first measurement of monoenergetic muon neutrino charged current interactions. MiniBooNE has isolated 236 MeV muon neutrino events originating from charged kaon decay at rest (K+μ+νμK^+ \rightarrow \mu^+ \nu_\mu) at the NuMI beamline absorber. These signal νμ\nu_\mu-carbon events are distinguished from primarily pion decay in flight νμ\nu_\mu and νμ\overline{\nu}_\mu backgrounds produced at the target station and decay pipe using their arrival time and reconstructed muon energy. The significance of the signal observation is at the 3.9σ\sigma level. The muon kinetic energy, neutrino-nucleus energy transfer (ω=EνEμ\omega=E_\nu-E_\mu), and total cross section for these events is extracted. This result is the first known-energy, weak-interaction-only probe of the nucleus to yield a measurement of ω\omega using neutrinos, a quantity thus far only accessible through electron scattering.Comment: 6 pages, 4 figure
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