2,114 research outputs found

    The potential negative impact of antibiotic pack on antibiotic stewardship in primary care in Switzerland: a modelling study.

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    BACKGROUND: In Switzerland, oral antibiotics are dispensed in packs rather than by exact pill-count. We investigated whether available packs support compliance with recommended primary care treatment regimens for common infections in children and adults. METHODS: Hospital-based guidelines for oral community -based treatment of acute otitis media, sinusitis, tonsillopharyngitis, community-acquired pneumonia and afebrile urinary tract infection were identified in 2017 in an iterative process by contacting hospital pharmacists and infectious diseases specialists. Furthermore, newly available national guidelines published in 2019 were reviewed. Available pack sizes for recommended solid, dispersible and liquid antibiotic formulations were retrieved from the Swiss pharmaceutical register and compared with recommended regimens to determine optimal (no leftovers) and adequate (optimal +/- one dose) matches. RESULTS: A large variety of recommended regimens were identified. For adults, optimal and adequate packs were available for 25/70 (36%) and 8/70 (11%) regimens, respectively. Pack-regimen matching was better for WHO Watch (optimal: 15/24, 63%) than Access antibiotics (optimal: 7/39, 18%). For the four paediatric weight-examples and 42 regimens involving child-appropriate formulations, optimal and adequate packs were available for only 14/168 (8%) and 27/168 (16%), respectively. Matching was better for older children with higher body and for longer treatment courses > 7 days. CONCLUSIONS: Fixed antibiotic packs often do not match recommended treatment regimens, especially for children, potentially resulting in longer than necessary treatments and leftover doses in the community. As part of national stewardship, a move to an exact pill-count system, including for child-appropriate solid formulations, should be considered

    Unambiguous state discrimination in quantum cryptography with weak coherent states

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    The use of linearly independent signal states in realistic implementations of quantum key distribution (QKD) enables an eavesdropper to perform unambiguous state discrimination. We explore quantitatively the limits for secure QKD imposed by this fact taking into account that the receiver can monitor to some extend the photon number statistics of the signals even with todays standard detection schemes. We compare our attack to the beamsplitting attack and show that security against beamsplitting attack does not necessarily imply security against the attack considered here.Comment: 10 pages, 6 figures, updated version with added discussion of beamsplitting attac

    Unambiguous State Discrimination of Coherent States with Linear Optics: Application to Quantum Cryptography

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    We discuss several methods for unambiguous state discrimination of N symmetric coherent states using linear optics and photodetectors. One type of measurements is shown to be optimal in the limit of small photon numbers for any N. For the special case of N=4 this measurement can be fruitfully used by the receiving end (Bob) in an implementation of the BB84 quantum key distribution protocol using faint laser pulses. In particular, if Bob detects only a single photon the procedure is equivalent to the standard measurement that he would have to perform in a single-photon implementation of BB84, if he detects two photons Bob will unambiguously know the bit sent to him in 50% of the cases without having to exchange basis information, and if three photons are detected, Bob will know unambiguously which quantum state was sent.Comment: 5 RevTeX pages, 2 eps figure

    ``Plug and play'' systems for quantum cryptography

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    We present a time-multiplexed interferometer based on Faraday mirrors, and apply it to quantum key distribution. The interfering pulses follow exactly the same spatial path, ensuring very high stability and self balancing. Use of Faraday mirrors compensates automatically any birefringence effects and polarization dependent losses in the transmitting fiber. First experimental results show a fringe visibility of 0.9984 for a 23km-long interferometer, based on installed telecom fibers.Comment: LaTex, 6 pages, with 2 Postscript figures, Submitted to Applied Physics Letter

    Field quantization in inhomogeneous anisotropic dielectrics with spatio-temporal dispersion

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    A quantum damped-polariton model is constructed for an inhomogeneous anisotropic linear dielectric with arbitrary dispersion in space and time. The model Hamiltonian is completely diagonalized by determining the creation and annihilation operators for the fundamental polariton modes as specific linear combinations of the basic dynamical variables. Explicit expressions are derived for the time-dependent operators describing the electromagnetic field, the dielectric polarization and the noise term in the latter. It is shown how to identify bath variables that generate the dissipative dynamics of the medium.Comment: 24 page

    Experimental test of higher-order Laguerre–Gauss modes in the 10 m Glasgow prototype interferometer

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    Brownian noise of dielectric mirror coatings is expected to be one of the limiting noise sources, at the peak sensitivity, of next generation ground based interferometric gravitational wave (GW) detectors. The use of higher-order Laguerre–Gauss (LG) beams has been suggested to reduce the effect of coating thermal noise in future generations of gravitational wave detectors. In this paper we describe the first test of interferometry with higher-order LG beams in an environment similar to a full-scale gravitational wave detector. We compare the interferometric performance of higher-order LG modes and the fundamental mode beams, injected into a 10 m long suspended cavity that features a finesse of 612, a value chosen to be typical of future gravitational wave detectors. We found that the expected mode degeneracy of the injected LG3, 3 beam was resolved into a multiple peak structure, and that the cavity length control signal featured several nearby zero crossings. The break up of the mode degeneracy is due to an astigmatism (defined as |Rcy − Rcx|) of 5.25 ± 0.5 cm on one of our cavity mirrors with a radius of curvature (Rc) of 15 m. This observation agrees well with numerical simulations developed with the FINESSE software. We also report on how these higher-order mode beams respond to the misalignment and mode mismatch present in our 10 m cavity. In general we found the LG3, 3 beam to be considerably more susceptible to astigmatism and mode mismatch than a conventional fundamental mode beam. Therefore the potential application of higher-order Laguerre–Gauss beams in future gravitational wave detectors will impose much more stringent requirements on both mode matching and mirror astigmatism
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