973 research outputs found

    Bichromatic UV detection system for atomically-resolved imaging of ions

    Full text link
    We present a compact and bichromatic imaging system, located outside of the vacuum chamber of a trapped ion apparatus, that collects the fluorescence of 230.6 nm and 369.5 nm photons simultaneously on a shared EMCCD camera. The system contains two lens doublets, consisting of a sphere and an asphere. It provides a numerical aperture of 0.45 and 0.40 at 230.6 nm and 369.5 nm, respectively, and enables spatially resolved state detection with a large field of view of 300 μ\mum for long 115^{115}In+^+/172^{172}Yb+^+ Coulomb crystals. Instead of diffraction limited imaging for one wavelength, the focus in this system is on simultaneous single-ion resolved imaging of both species over a large field with special attention to the deep UV wavelength (230.6 nm) and the low scattering rate of In+^+ ions. The introduced concept is applicable to other dual-species applications

    Sub-kelvin temperature management in ion traps for optical clocks

    Full text link
    The uncertainty of the ac Stark shift due to thermal radiation represents a major contribution to the systematic uncertainty budget of state-of-the-art optical atomic clocks. In the case of optical clocks based on trapped ions, the thermal behavior of the rf-driven ion trap must be precisely known. This determination is even more difficult when scalable linear ion traps are used. Such traps enable a more advanced control of multiple ions and have become a platform for new applications in quantum metrology, simulation and computation. Nevertheless, their complex structure makes it more difficult to precisely determine its temperature in operation and thus the related systematic uncertainty. We present here scalable linear ion traps for optical clocks, which exhibit very low temperature rise under operation. We use a finite-element model refined with experimental measurements to determine the thermal distribution in the ion trap and the temperature at the position of the ions. The trap temperature is investigated at different rf-drive frequencies and amplitudes with an infrared camera and integrated temperature sensors. We show that for typical trapping parameters for In+\mathrm{In}^{+}, Al+\mathrm{Al}^{+}, Lu+\mathrm{Lu}^{+}, Ca+\mathrm{Ca}^{+}, Sr+\mathrm{Sr}^{+} or Yb+\mathrm{Yb}^{+} ions, the temperature rise at the position of the ions resulting from rf heating of the trap stays below 700 mK and can be controlled with an uncertainty on the order of a few 100 mK maximum.Comment: 18 page

    Molecular epidemiology of carbapenem-resistant Acinetobacter baumannii in New Caledonia

    Get PDF
    ABSTRACTCarbapenem-resistant Acinetobacter baumannii (CR-Ab) ranked third, with a frequency of 24.8%, among 202 strains of multidrug-resistant bacteria isolated from clinical samples in the main hospital of New Caledonia in 2004. All CR-Ab isolates were analysed by isoelectric focusing, conjugation, pulsed-field gel electrophoresis and PCR for the presence of carbapenemase genes. Fifty CR-Ab isolates produced carbapenemase OXA-23. The isolates belonged to a single clone presenting several subtypes, suggesting an endemic situation. This study further illustrates the widespread prevalence of carbapenemase OXA-23-producing CR-Ab isolates in the South Pacific

    Management of female genital mutilation / cutting-related obstetric complications: a training evaluation

    Get PDF
    Although female genital mutilation/cutting (FGM/C) is a prevalent practice in Liberia, healthcare workers lack the capacity to provide adequate care for FGM/C survivors. Therefore, Liberian nurses, physician assistants, midwives and trained traditional midwives were trained in sexual, obstetric and psychosocial care for FGM/C survivors in 2019. Through questionnaires, we assessed knowledge acquisition, trainee attitudes towards FGM/C care and acceptability to implement WHO-endorsed recommendations. The questionnaires were analyzed using descriptive statistics for quantitative data and an inductive approach for qualitative data. A total of 99 female and 34 male trainees participated. Most trainees perceived FGM/C as harmful to women''s health, as a violation of women''s rights and showed a willingness to change their clinical practice. While 82.8% (n = 74/90) perceived their role in advocating against FGM/C, 10.0% (n = 9/90) felt that they should train traditional circumcisers to practice FGM/C safely. The pre-training FGM/C knowledge test demonstrated higher scores among physician assistants (13.86 ± 3.02 points) than among nurses (12.11 ± 3.12 points) and midwives (11.75 ± 2.27 points). After the training, the mean test score increased by 1.69 points, from 12.18 (±2.91) points to 13.87 (±2.65) points. The trainings successfully increased theoretical knowledge of FGM/C-caused health effects and healthcare workers'' demonstrated willingness to implement evidence-based guidelines when providing care to FMG/C survivors

    Emergence of Escherichia coli producing OXA-48 β-lactamase in the community in Switzerland

    Get PDF
    The emergence and worldwide spread of carbapenemase-producing Enterobacteriaceae is of great concern to public health services. The aim of this study was to investigate the occurrence of carbapenemase-producing Enterobacteriaceae in the community in Switzerland.Findings: One thousand and eighty-six stool samples of healthy humans (staff members of a food-processing company which were screened for the occurrence of salmonellae) were collected in September 2014. After an initial enrichment-step, carbapenemase-producing Enterobacteriaceae were isolated from the carbapenem-containing selective medium SUPERCARBA II. Grown colonies from 11 samples were screened by PCR for the presence of bla KPC, bla NDM, bla OXA-48 and bla VIM. A single OXA-48-producing Escherichia coli was detected. Phylogenetic grouping and multi-locus sequence typing (MLST) revealed that this strain belonged to D:ST38, a type which had been previously reported in the UK, France, Lebanon and Egypt.Conclusions: The results of this study show that OXA-48-producing Enterobacteriaceae have started to spread into the community in Switzerland, and a continuous monitoring is necessary to better understand their dissemination in the human population as well as in animals and the environment

    EVALUATION OF PREHOSPITAL BLOOD PRODUCTS TO ATTENUATE ACUTE COAGULOPATHY OF TRAUMA IN A MODEL OF SEVERE INJURY AND SHOCK IN ANESTHETIZED PIGS

    Get PDF
    This material is licensed under the terms of the Open Government Licence except where otherwise statedUK Ministry of Defence

    How to detect carbapenemase producers? A literature review of phenotypic and molecular methods

    Get PDF
    © 2014 Elsevier B.V. This review describes the current state-of-art of carbapenemase detection methods. Identification of carbapenemases is first based on conventional phenotypic tests including antimicrobial susceptibility testing, modified-Hodge test and carbapenemase-inhibitor culture tests. Second, molecular characterization of carbapenemase genes by PCR sequencing is essential. Third, innovative biochemical and spectrometric detection may be applied
    corecore