77 research outputs found

    Functional outcomes in adult patients with herpes simplex encephalitis admitted to the ICU: a multicenter cohort study

    Get PDF
    PURPOSE: We aimed to study the association of body temperature and other admission factors with outcomes of herpes simplex encephalitis (HSE) adult patients requiring ICU admission. METHODS: We conducted a retrospective multicenter study on patients diagnosed with HSE in 47 ICUs in France, between 2007 and 2017. Fever was defined as a body temperature higher or equal to 38.3 °C. Multivariate logistic regression analysis was used to identify factors associated with poor outcome at 90 days, defined by a score of 3-6 (indicating moderate-to-severe disability or death) on the modified Rankin scale. RESULTS: Overall, 259 patients with a score on the Glasgow coma scale of 9 (6-12) and a body temperature of 38.7 (38.1-39.2) °C at admission were studied. At 90 days, 185 (71%) patients had a poor outcome, including 44 (17%) deaths. After adjusting for age, fever (OR = 2.21; 95% CI 1.18-4.16), mechanical ventilation (OR = 2.21; 95% CI 1.21-4.03), and MRI brain lesions > 3 lobes (OR = 3.04; 95% CI 1.35-6.81) were independently associated with poor outcome. By contrast, a direct ICU admission, as compared to initial admission to the hospital wards (i.e., indirect ICU admission), was protective (OR = 0.52; 95% CI 0.28-0.95). Sensitivity analyses performed after adjustment for functional status before admission and reason for ICU admission yielded similar results. CONCLUSIONS: In HSE adult patients requiring ICU admission, several admission factors are associated with an increased risk of poor functional outcome. The identification of potentially modifiable factors, namely, elevated admission body temperature and indirect ICU admission, provides an opportunity for testing further intervention strategies

    Who needs contacts? Optical fiber poling by induction

    No full text
    Conventional thermal poling methods require direct physical contact to internal fibers electrodes. Here, we report a novel indirect method in which external fields are used to charge floating internal electrodes to generate depletion regions for SHG

    Highly efficient surface enhanced Raman scattering using microstructured optical fibers with enhanced plasmonic interactions

    No full text
    Microstructured optical fibers "MOFs" represent a promising platform technology for fully integrated photonic-plasmonic devices. In this paper, we experimentally investigate the properties of two MOF templates impregnated with silver nanoparticles via a high pressure chemical deposition technique. By comparing fiber templates with different air filling fractions, we have quantified the importance of an increased field-particle overlap for improved surface enhanced Raman scattering sensitivity for the next generation of optical fiber sensors

    Experimental observation of whispering gallery modes in novel silicon microcylindrical resonators

    No full text
    Microresonators that support whispering gallery modes (WGMs) are ideal systems for studying nonlinear phenomena at low thresholds due to the small mode volumes and the high quality (Q) factors and, as such, they are currently generating much scientific interest [1]. A variety of geometries have been investigated including microspheres, microdisks, toroids and micropillars, using a range of dielectrics and, more recently, semiconductor materials. One of the major challenges in fabricating semiconductor microresonators is obtaining the smooth, defect-free, surfaces required for high Q operation. In this paper, we present a novel approach to fabricating high quality silicon microcylindrical resonators starting from the silicon optical fibre platform [2]. The silicon fibres are fabricated using a high pressure chemical deposition technique to fill silica capillaries with the semiconductor material. This process can be easily modified to fill capillaries of various internal diameters with the deposited material taking on the pristine smoothness of the capillary walls (0.1 nm RMS). As an optical material, silicon is particularly attractive due to its broad transparency window that extends from the telecoms band to the mid-IR (~1.2–7µm), as well as its high optical damage threshold and large nonlinearities

    Time and spectrally resolved enhanced fluorescence using silver nanoparticle impregnated polycarbonate substrates

    No full text
    Silver nanoparticle impregnated polycarbonate strips have been investigated as substrates for metal-enhanced photoluminescence of a blue emitting dye molecule (coumarin 102). By considering simultaneous time and spectrally resolved photoluminescence we observed fluorescence enhancement resulting from plasmon coupling with an increase in the emission by a factor of ~8.5 with an associated reduction in the photon lifetime. We relate the fast and slow components of the observed emission decay to the presence of both monomers and aggregates in the films and we discuss their different responses to the plasmon coupling

    Mid-infrared transmission properties of amorphous germanium optical fibers

    No full text
    Germanium optical fibers have been fabricated using a high pressure chemical deposition technique to deposit the semiconductor material inside a silica capillary. The amorphous germanium core material has a small percentage of hydrogen that saturates the dangling bonds to reduce absorption loss. Optical transmission measurements were performed to determine the linear losses over a broad mid-infrared wavelength range with the lowest loss recorded at 10.6 µm. The extended transmission range measured in the germanium fibers demonstrates their potential for use in mid-infrared applications

    Thermal nonlinearity in silicon microcylindrical resonators

    No full text
    We explore the thermally induced nonlinearity in hydrogenated amorphous silicon microcylindrical resonators that are fabricated from the silicon optical fiber platform. In particular, we use a pump-probe technique to experimentally demonstrate thermally induced optical modulation and determine the response time. Through characterization of the thermal properties and the associated resonance wavelength shifts we will show that it is possible to infer the material absorption coefficient for a range of whispering gallery mode resonators

    Erratum: Highly efficient blue photoluminescence from colloidal lead-iodide nanoparticles:(Journal of Physics D: Applied Physics (2006) 39 (1477-80))

    No full text
    In a recent paper (Finlayson C E and Sazio P J A 2006 J. Phys. D: Appl. Phys. 39 1477–80) we reported on the properties of colloidal lead (II) iodide nanoparticles, synthesized via a route using coordinating solvents. Our samples were characterized as having highly efficient and photostable photoluminescence in the blue region of the visible spectrum. Subsequent experiments show the observed behaviour of these nanoparticles during nucleation and ripening to be more complicated than originally reported and we believe that the observed photoluminescence may be related to extraneous factors, beyond the experimental methods as previously described
    • …
    corecore