484 research outputs found

    Shoulder dysfunction in intensive care survivors:an investigation into prevalence, risk factors and impact on upper limb function

    Get PDF
    Background: Limitations in function and quality of life have been reported in intensive care unit survivors for many years after hospital discharge. Shoulder dysfunction is a cause of functional limitation in other patient populations, and has been suggested as a potential cause in intensive care unit survivors. Despite this, the prevalence of shoulder dysfunction, its impact on upper limb function and risk factors for its development are unknown in intensive care unit survivors. Methods: A cohort study of intensive care unit survivors from a single general intensive care unit was undertaken using prospective and retrospective data. Participants underwent a series of shoulder assessments up to 6 months after hospital discharge to identify shoulder dysfunction and upper limb impairment. Multivariable analysis was used to investigate the risk factors for developing shoulder dysfunction. Results: Shoulder dysfunction was present in 76% of participants, with 42% presenting with ongoing shoulder dysfunction at 6 months after hospital discharge. Functional impairment of the upper limb was present in 48% of participants and severe impairment in 18%. None of the risk factors analysed were independently associated with shoulder dysfunction. Conclusions: Shoulder dysfunction is a common problem in intensive care unit survivors, and is a source of functional impairment. Further investigation addressing risk factors for its development, and therapeutic interventions to address this problem is required

    The effectiveness of prehabilitation interventions on biopsychosocial and service outcomes pre and post upper gastrointestinal surgery : a systematic review

    Get PDF
    Purpose. This review synthesised the evidence for the effect of prehabilitation interventions on biopsychosocial and service outcomes. Materials and Methods. A systematic review was conducted. 10 databases were searched to December 2023. Prospective experimental studies exploring prehabilitation interventions in adults undergoing upper gastrointestinal surgery were included. Prehabilitation was any preoperative intervention to improve physical or psychological outcomes. Included studies required a comparator group or alternative preoperative intervention as well as baseline, presurgical and postoperative assessment points. Study quality was assessed using the Cochrane risk of bias tool (v.2). Data synthesis was narrative (SWiM guidance). Results. 6028 studies were screened, with 25 studies included. Prehabilitation interventions were: inspiratory muscle training (five studies n = 450); exercise (nine studies n = 683); psychological (one study n = 400); and nutritional (ten studies n = 487). High quality studies showed preoperative improvements in impairments directly targeted by the interventions. Generally, these did not translate into functional or postoperative improvements, but multimodal interventions were more promising. Conclusion. Current evidence supports prehabilitation as safe to preserve or improve preoperative function. Heterogeneity in outcomes and variable study quality means definitive conclusions regarding interventions are not yet possible, limiting implementation. Agreement of clinical outcomes and cost effectiveness evaluation is required

    Effect of Silicon Content on Carbide Precipitation and Low-Temperature Toughness of Pressure Vessel Steels

    Get PDF
    Cr – Mn – Mo – Ni pressure vessel steels containing 0.54 and 1.55% Si are studied. Metallographic and fractographic analyses of the steels after tempering at 650 and 700°C are performed. The impact toughness at – 30°C and the hardness of the steels are determined. The mass fraction of the carbide phase in the steels is computed with the help of the J-MatPro 4.0 software

    Searching for gravitational waves from Cassiopeia A with LIGO

    Get PDF
    We describe a search underway for periodic gravitational waves from the central compact object in the supernova remnant Cassiopeia A. The object is the youngest likely neutron star in the Galaxy. Its position is well known, but the object does not pulse in any electromagnetic radiation band and thus presents a challenge in searching the parameter space of frequency and frequency derivatives. We estimate that a fully coherent search can, with a reasonable amount of time on a computing cluster, achieve a sensitivity at which it is theoretically possible (though not likely) to observe a signal even with the initial LIGO noise spectrum. Cassiopeia A is only the second object after the Crab pulsar for which this is true. The search method described here can also obtain interesting results for similar objects with current LIGO sensitivity.Comment: 8 pages, 1 figure; accepted to Classical and Quantum Gravit

    Upper limits on the strength of periodic gravitational waves from PSR J1939+2134

    Get PDF
    The first science run of the LIGO and GEO gravitational wave detectors presented the opportunity to test methods of searching for gravitational waves from known pulsars. Here we present new direct upper limits on the strength of waves from the pulsar PSR J1939+2134 using two independent analysis methods, one in the frequency domain using frequentist statistics and one in the time domain using Bayesian inference. Both methods show that the strain amplitude at Earth from this pulsar is less than a few times 102210^{-22}.Comment: 7 pages, 1 figure, to appear in the Proceedings of the 5th Edoardo Amaldi Conference on Gravitational Waves, Tirrenia, Pisa, Italy, 6-11 July 200

    Improving the sensitivity to gravitational-wave sources by modifying the input-output optics of advanced interferometers

    Get PDF
    We study frequency dependent (FD) input-output schemes for signal-recycling interferometers, the baseline design of Advanced LIGO and the current configuration of GEO 600. Complementary to a recent proposal by Harms et al. to use FD input squeezing and ordinary homodyne detection, we explore a scheme which uses ordinary squeezed vacuum, but FD readout. Both schemes, which are sub-optimal among all possible input-output schemes, provide a global noise suppression by the power squeeze factor, while being realizable by using detuned Fabry-Perot cavities as input/output filters. At high frequencies, the two schemes are shown to be equivalent, while at low frequencies our scheme gives better performance than that of Harms et al., and is nearly fully optimal. We then study the sensitivity improvement achievable by these schemes in Advanced LIGO era (with 30-m filter cavities and current estimates of filter-mirror losses and thermal noise), for neutron star binary inspirals, and for narrowband GW sources such as low-mass X-ray binaries and known radio pulsars. Optical losses are shown to be a major obstacle for the actual implementation of these techniques in Advanced LIGO. On time scales of third-generation interferometers, like EURO/LIGO-III (~2012), with kilometer-scale filter cavities, a signal-recycling interferometer with the FD readout scheme explored in this paper can have performances comparable to existing proposals. [abridged]Comment: Figs. 9 and 12 corrected; Appendix added for narrowband data analysi

    Analysis of LIGO data for gravitational waves from binary neutron stars

    Get PDF
    We report on a search for gravitational waves from coalescing compact binary systems in the Milky Way and the Magellanic Clouds. The analysis uses data taken by two of the three LIGO interferometers during the first LIGO science run and illustrates a method of setting upper limits on inspiral event rates using interferometer data. The analysis pipeline is described with particular attention to data selection and coincidence between the two interferometers. We establish an observational upper limit of R<\mathcal{R}<1.7 \times 10^{2}peryearperMilkyWayEquivalentGalaxy(MWEG),with90coalescencerateofbinarysystemsinwhicheachcomponenthasamassintherange13 per year per Milky Way Equivalent Galaxy (MWEG), with 90% confidence, on the coalescence rate of binary systems in which each component has a mass in the range 1--3 M_\odot$.Comment: 17 pages, 9 figure

    Searching for gravitational waves from known pulsars

    Get PDF
    We present upper limits on the amplitude of gravitational waves from 28 isolated pulsars using data from the second science run of LIGO. The results are also expressed as a constraint on the pulsars' equatorial ellipticities. We discuss a new way of presenting such ellipticity upper limits that takes account of the uncertainties of the pulsar moment of inertia. We also extend our previous method to search for known pulsars in binary systems, of which there are about 80 in the sensitive frequency range of LIGO and GEO 600.Comment: Accepted by CQG for the proceeding of GWDAW9, 7 pages, 2 figure

    Setting upper limits on the strength of periodic gravitational waves from PSR J1939+2134 using the first science data from the GEO 600 and LIGO detectors

    Get PDF
    Data collected by the GEO 600 and LIGO interferometric gravitational wave detectors during their first observational science run were searched for continuous gravitational waves from the pulsar J1939+2134 at twice its rotation frequency. Two independent analysis methods were used and are demonstrated in this paper: a frequency domain method and a time domain method. Both achieve consistent null results, placing new upper limits on the strength of the pulsar's gravitational wave emission. A model emission mechanism is used to interpret the limits as a constraint on the pulsar's equatorial ellipticity

    First LIGO search for gravitational wave bursts from cosmic (super)strings

    Get PDF
    We report on a matched-filter search for gravitational wave bursts from cosmic string cusps using LIGO data from the fourth science run (S4) which took place in February and March 2005. No gravitational waves were detected in 14.9 days of data from times when all three LIGO detectors were operating. We interpret the result in terms of a frequentist upper limit on the rate of gravitational wave bursts and use the limits on the rate to constrain the parameter space (string tension, reconnection probability, and loop sizes) of cosmic string models.Comment: 11 pages, 3 figures. Replaced with version submitted to PR
    corecore