628 research outputs found
What is the evidence base of used aggregated antibiotic resistance percentages to change empirical antibiotic treatment? A scoping review
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251404.pdf (Publisherâs version ) (Open Access)OBJECTIVES: Antibiotic resistance requires continuous monitoring by experts to decide whether empirical antibiotic therapies (EATs) should be replaced by alternative antibiotics. The exact moment and criteria for this change are unclear and generally based on consensus between experts. This scoping review aims to identify from the literature the resistance thresholds used for a change in EAT and the criteria on which they are based. METHODS: Scoping review for which a comprehensive structured literature search was conducted. Rayyan, software for systematic reviews, was used for the screening of abstracts and titles. Data sources were Pubmed and a hand-search of reference lists and grey literature. Papers were eligible if they concerned any type of bacterial infectious disease and mentioned or defined antibiotic resistance thresholds for decision-making purposes for EAT. The inclusion and analysis of articles was done by two researchers; any conflicts were resolved through discussion or by consulting a third reviewer. RESULTS: We identified 3146 unique papers. Following title/abstract screening, 125 papers were comprehensively read, and 16 papers were included. The included papers gave thresholds for urinary tract infections, respiratory tract infections, meningitis, skin and soft tissue infections, gonorrhoea, and bone and joint infections. Six criteria were found that were commonly used to base the thresholds on. These were: disease severity, efficacy of treatment, adverse drug events, risk of Clostridioides difficile infection, costs, and increased resistance. The number of criteria used to define each threshold varied from one to six between papers. CONCLUSIONS: The thresholds used for EATs are few, commonly based on expert opinion estimates, and can therefore have broad ranges. Used criteria underlying reported thresholds are heterogenous and require standardization. Considering the rising trend in resistance, there is a clear need for rigid tools to determine thresholds in order to support guideline development with the best and timely evidence
Total Donor Chimerism in the Day 21 Bone Marrow Predicts Sustained Donor Neutrophil Engraftment Following Double Unit Cord Blood Transplantation (CBT)
Global change and groundwater
Groundwater (contained in sediments and rocks) constitutes the planetâs predominant reserve of fresh water, commonly with storage times from decades to centuries and millennia. Groundwater resources thus provide an excellent âbufferâ against the effects of climate variability on surface-water supplies, because of the generally large and widely-
distributed storage reserves of aquifer systems. But questions
arise as to how naturally resilient are groundwater reserves themselves to global change, and whether we are doing enough to help conserve and protect them
Significance of E-lesions in Hodgkin lymphoma and the creation of a new consensus definition:a report from SEARCH
The International Staging Evaluation and Response Criteria Harmonization for Childhood, Adolescent, and Young Adult Hodgkin Lymphoma (SEARCH for CAYAHL) seeks to provide an appropriate, universal differentiation between E-lesions and stage IV extranodal disease in Hodgkin lymphoma (HL). A literature search was performed through the PubMed and Google Scholar databases using the terms âHodgkin disease,â and âextranodal,â âextralymphatic,â âE lesions,â âE stage,â or âE disease.â Publications were reviewed for the number of participants; median age and age range; diagnostic modalities used for staging; and the definition, incidence, and prognostic significance of E-lesions. Thirty-six articles describing 12 640 patients met the inclusion criteria. Most articles reported staging per the Ann Arbor (72%, 26/36) or Cotswolds modification of the Ann Arbor staging criteria (25%, 9/36), and articles rarely defined E-lesions or disambiguated âextranodal disease.â The overall incidence of E-lesions for patients with stage I-III HL was 11.5% (1330/11 602 unique patients). Available stage-specific incidence analysis of 3888 patients showed a similar incidence of E-lesions in stage II (21.2%) and stage III (21.9%), with E-lesions rarely seen with stage I disease (1.1%). E-lesions likely remain predictive, but we cannot unequivocally conclude that identifying E-lesions in HL imparts prognostic value in the modern era of the more selective use of targeted radiation therapy. A harmonized E-lesion definition was reached based on the available evidence and the consensus of the SEARCH working group. We recommend that this definition of E-lesion be applied in future clinical trials with explicit reporting to confirm the prognostic value of E-lesions.</p
Flux noise in high-temperature superconductors
Spontaneously created vortex-antivortex pairs are the predominant source of
flux noise in high-temperature superconductors. In principle, flux noise
measurements allow to check theoretical predictions for both the distribution
of vortex-pair sizes and for the vortex diffusivity. In this paper the
flux-noise power spectrum is calculated for the highly anisotropic
high-temperature superconductor Bi-2212, both for bulk crystals and for
ultra-thin films. The spectrum is basically given by the Fourier transform of
the temporal magnetic-field correlation function. We start from a
Berezinskii-Kosterlitz-Thouless type theory and incorporate vortex diffusion,
intra-pair vortex interaction, and annihilation of pairs by means of a
Fokker-Planck equation to determine the noise spectrum below and above the
superconducting transition temperature. We find white noise at low frequencies
omega and a spectrum proportional to 1/omega^(3/2) at high frequencies. The
cross-over frequency between these regimes strongly depends on temperature. The
results are compared with earlier results of computer simulations.Comment: 9 pages, 4 PostScript figures, to be published in Phys. Rev.
Dynamic Scaling and Two-Dimensional High-Tc Superconductors
There has been ongoing debate over the critical behavior of two-dimensional
superconductors; in particular for high Tc superconductors. The conventional
view is that a Kosterlitz-Thouless-Berezinskii transition occurs as long as
finite size effects do not obscure the transition. However, there have been
recent suggestions that a different transition actually occurs which
incorporates aspects of both the dynamic scaling theory of Fisher, Fisher, and
Huse and the Kosterlitz-Thouless-Berezinskii transition. Of general interest is
that this modified transition apparently has a universal dynamic critical
exponent. Some have countered that this apparent universal behavior is rooted
in a newly proposed finite-size scaling theory; one that also incorporates
scaling and conventional two-dimensional theory. To investigate these issues we
study DC voltage versus current data of a 12 angstrom thick YBCO film. We find
that the newly proposed scaling theories have intrinsic flexibility that is
relevant to the analysis of the experiments. In particular, the data scale
according to the modified transition for arbitrarily defined critical
temperatures between 0 K and 19.5 K, and the temperature range of a successful
scaling collapse is related directly to the sensitivity of the measurement.
This implies that the apparent universal exponent is due to the intrinsic
flexibility rather than some real physical property. To address this intrinsic
flexibility, we propose a criterion which would give conclusive evidence for
phase transitions in two-dimensional superconductors. We conclude by reviewing
results to see if our criterion is satisfied.Comment: 14 page
First Measurement of Z/gamma* Production in Compton Scattering of Quasi-real Photons
We report the first observation of Z/gamma* production in Compton scattering
of quasi-real photons. This is a subprocess of the reaction e+e- to
e+e-Z/gamma*, where one of the final state electrons is undetected.
Approximately 55 pb-1 of data collected in the year 1997 at an e+e-
centre-of-mass energy of 183 GeV with the OPAL detector at LEP have been
analysed. The Z/gamma* from Compton scattering has been detected in the
hadronic decay channel. Within well defined kinematic bounds, we measure the
product of cross-section and Z/gamma* branching ratio to hadrons to be
(0.9+-0.3+-0.1) pb for events with a hadronic mass larger than 60 GeV,
dominated by (e)eZ production. In the hadronic mass region between 5 GeV and 60
GeV, dominated by (e)egamma* production, this product is found to be
(4.1+-1.6+-0.6) pb. Our results agree with the predictions of two Monte Carlo
event generators, grc4f and PYTHIA.Comment: 18 pages, LaTeX, 5 eps figures included, submitted to Physics Letters
Calsequestrin as a risk factor in Gravesâ hyperthyroidism and Gravesâ ophthalmopathy patients
Background: The pathogenesis of Gravesâ ophthalmopathy (GO), Gravesâ hyperthyroidism (GH) and the mechanisms for its link to thyroid autoimmunity are poorly understood. Our research focuses on the role of the skeletal muscle calcium binding protein calsequestrin (CASQ1) in thyroid. We measured the concentration of the CASQ1 protein correlating levels with parameters of the eye signs, CASQ1 antibody levels and CASQ1 gene polymorphism rs3838284. Methods: CASQ1 protein was measured by quantitative Western Blotting. The protein concentrations were expressed as pmol/mg total protein by reference to CASQ1 standards. Results: Western blot analysis showed the presence of two forms of CASQ1 in the thyroid. The mean concentration of CASQ1 protein was significantly reduced in patients with Gravesâ disease, compared to thyroid from control subjects with multi-nodular goitre or thyroid cancer. Although in patients with GO it was lower than that, compared with patients with GH this difference was not significant. Reduced CASQ1 in Gravesâ thyroid correlated with the homozygous genotype of the rs3838284 CASQ1 polymorphism. Conclusions: Decreased CASQ1 in the thyroid of patients with Gravesâ disease compared to thyroid from control subjects is not explained but may reflect consumption of the protein during an autoimmune reaction against CASQ1 in the thyroid
Search for Higgs Bosons in e+e- Collisions at 183 GeV
The data collected by the OPAL experiment at sqrts=183 GeV were used to
search for Higgs bosons which are predicted by the Standard Model and various
extensions, such as general models with two Higgs field doublets and the
Minimal Supersymmetric Standard Model (MSSM). The data correspond to an
integrated luminosity of approximately 54pb-1. None of the searches for neutral
and charged Higgs bosons have revealed an excess of events beyond the expected
background. This negative outcome, in combination with similar results from
searches at lower energies, leads to new limits for the Higgs boson masses and
other model parameters. In particular, the 95% confidence level lower limit for
the mass of the Standard Model Higgs boson is 88.3 GeV. Charged Higgs bosons
can be excluded for masses up to 59.5 GeV. In the MSSM, mh > 70.5 GeV and mA >
72.0 GeV are obtained for tan{beta}>1, no and maximal scalar top mixing and
soft SUSY-breaking masses of 1 TeV. The range 0.8 < tanb < 1.9 is excluded for
minimal scalar top mixing and m{top} < 175 GeV. More general scans of the MSSM
parameter space are also considered.Comment: 49 pages. LaTeX, including 33 eps figures, submitted to European
Physical Journal
Measurement of the Strong Coupling alpha s from Four-Jet Observables in e+e- Annihilation
Data from e+e- annihilation into hadrons at centre-of-mass energies between
91 GeV and 209 GeV collected with the OPAL detector at LEP, are used to study
the four-jet rate as a function of the Durham algorithm resolution parameter
ycut. The four-jet rate is compared to next-to-leading order calculations that
include the resummation of large logarithms. The strong coupling measured from
the four-jet rate is alphas(Mz0)=
0.1182+-0.0003(stat.)+-0.0015(exp.)+-0.0011(had.)+-0.0012(scale)+-0.0013(mass)
in agreement with the world average. Next-to-leading order fits to the
D-parameter and thrust minor event-shape observables are also performed for the
first time. We find consistent results, but with significantly larger
theoretical uncertainties.Comment: 25 pages, 15 figures, Submitted to Euro. Phys. J.
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