575 research outputs found

    MRSA eradication of newly acquired lower respiratory tract infection in cystic fibrosis

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    UK cystic fibrosis (CF) guidelines recommend eradication of methicillin-resistant Staphylococcus aureus (MRSA) when cultured from respiratory samples. As there is no clear consensus as to which eradication regimen is most effective, we determined the efficacy of eradication regimens used in our CF centre and long-term clinical outcome. All new MRSA positive sputum cultures (n=37) that occurred between 2000 and 2014 were reviewed. Eradication regimen characteristics and clinical, microbiological and long-term outcome data were collected. Rifampicin plus fusidic acid was the most frequently used regimen (24 (65%) out of 37 patients), with an overall success rate of 79% (19 out of 24 patients). Eradication failure was more likely in patients with an additional MRSA-positive peripheral screening swab (p=0.03) and was associated with worse survival (p=0.04). Our results demonstrate the feasibility and clinical benefits of MRSA eradication. As peripheral colonisation was associated with lower eradication success, strategies combining systemic and topical treatments should be considered to optimise outcomes in CF patients

    Free space-coupled superconducting nanowire single photon detectors for infrared optical communications

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    This paper describes the construction of a cryostat and an optical system with a free-space coupling efficiency of 56.5% +/- 3.4% to a superconducting nanowire single-photon detector (SNSPD) for infrared quantum communication and spectrum analysis. A 1K pot decreases the base temperature to T = 1.7 K from the 2.9 K reached by the cold head cooled by a pulse-tube cryocooler. The minimum spot size coupled to the detector chip was 6.6 +/- 0.11 {\mu}m starting from a fiber source at wavelength, {\lambda} = 1.55 {\mu}m. We demonstrated efficient photon counting on a detector with an 8 x 7.3 {\mu}m^2 area. We measured a dark count rate of 95 +/- 3.35 kcps and a system detection efficiency of 1.64% +/- 0.13%. We explain the key steps that are required to further improve the coupling efficiency.Comment: 16 pages, double-space

    The Benard problem: A comparison of finite difference and spectral collocation eigen value solutions

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    The application of spectral methods, using a Chebyshev collocation scheme, to solve hydrodynamic stability problems is demonstrated on the Benard problem. Implementation of the Chebyshev collocation formulation is described. The performance of the spectral scheme is compared with that of a 2nd order finite difference scheme. An exact solution to the Marangoni-Benard problem is used to evaluate the performance of both schemes. The error of the spectral scheme is at least seven orders of magnitude smaller than finite difference error for a grid resolution of N = 15 (number of points used). The performance of the spectral formulation far exceeded the performance of the finite difference formulation for this problem. The spectral scheme required only slightly more effort to set up than the 2nd order finite difference scheme. This suggests that the spectral scheme may actually be faster to implement than higher order finite difference schemes

    Priorities for the professional development of registered nurses in nursing homes: a Delphi study

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    Objective: to establish a consensus on the care and professional development needs of registered nurses (RNs) employed by UK care homes. Design: two-stage, online modified Delphi study. Setting and participants: a panel (n = 352) of individuals with experience, expertise or interest in care home nursing: (i) care home nurses and managers; (ii) community healthcare professionals (including general practitioners, geriatricians, specialist and district nurses); and (iii) nurse educators in higher education. Results: RNs employed by nursing homes require particular skills, knowledge, competence and experience to provide high-quality care for older residents. The most important responsibilities for the nursing home nurse were: promoting dignity, personhood and wellbeing, ensuring resident safety and enhancing quality of life. Continuing professional development priorities included personal care, dementia care and managing long-term conditions. The main barrier to professional development was staff shortages. Nursing degree programmes were perceived as inadequately preparing nurses for a nursing home role. Nursing homes could improve by providing supportive learning opportunities for students and fostering challenging and rewarding careers for newly RNs. Conclusion: if nurses employed by nursing homes are not fit for purpose, the consequences for the wider health and social-care system are significant. Nursing homes, the NHS, educational and local authorities need to work together to provide challenging and rewarding career paths for RNs and evaluate them. Without well-trained, motivated staff, a high-quality care sector will remain merely an aspiration

    A nanoCryotron comparator can connect single-flux quantum circuits to conventional electronics

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    Integration with conventional electronics offers a straightforward and economical approach to upgrading existing superconducting technologies, such as scaling up superconducting detectors into large arrays and combining single flux quantum (SFQ) digital circuits with semiconductor logic and memories. However, direct output signals from superconducting devices (e.g., Josephson junctions) are usually not compatible with the input requirements of conventional devices (e.g., transistors). Here, we demonstrate the use of a single three-terminal superconducting-nanowire device, called the nanocryotron (nTron), as a digital comparator to combine SFQ circuits with mature semiconductor circuits such as complementary metal oxide semiconductor (CMOS) circuits. Since SFQ circuits can digitize output signals from general superconducting devices and CMOS circuits can interface existing CMOS-compatible electronics, our results demonstrate the feasibility of a general architecture that uses an nTron as an interface to realize a super-hybrid system consisting of superconducting detectors, superconducting quantum electronics, CMOS logic and memories, and other conventional electronics

    Comprehensive Investigation of the Caveolin 2 Gene: Resequencing and Association for Kidney Transplant Outcomes

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    Caveolae are plasma membrane structures formed from a complex of the proteins caveolin-1 and caveolin-2. Caveolae interact with pro-inflammatory cytokines and are dysregulated in fibrotic disease. Although caveolae are present infrequently in healthy kidneys, they are abundant during kidney injury. An association has been identified between a CAV1 gene variant and long term kidney transplant survival. Chronic, gradual decline in transplant function is a persistent problem in kidney transplantation. The aetiology of this is diverse but fibrosis within the transplanted organ is the common end point. This study is the first to investigate the association of CAV2 gene variants with kidney transplant outcomes. Genomic DNA from donors and recipients of 575 kidney transplants performed in Belfast was investigated for common variation in CAV2 using a tag SNP approach. The CAV2 SNP rs13221869 was nominally significant for kidney transplant failure. Validation was sought in an independent group of kidney transplant donors and recipients from Dublin, Ireland using a second genotyping technology. Due to the unexpected absence of rs13221869 from this cohort, the CAV2 gene was resequenced. One novel SNP and a novel insertion/deletion in CAV2 were identified; rs13221869 is located in a repetitive region and was not a true variant in resequenced populations. CAV2 is a plausible candidate gene for association with kidney transplant outcomes given its proximity to CAV1 and its role in attenuating fibrosis. This study does not support an association between CAV2 variation and kidney transplant survival. Further analysis of CAV2 should be undertaken with an awareness of the sequence complexities and genetic variants highlighted by this study

    Universal scaling of the critical temperature for thin films near the superconducting-to-insulating transition

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    Thin superconducting films form a unique platform for geometrically-confined, strongly-interacting electrons. They allow an inherent competition between disorder and superconductivity, which in turn enables the intriguing superconducting-to-insulator transition and believed to facilitate the comprehension of high-Tc superconductivity. Furthermore, understanding thin film superconductivity is technologically essential e.g. for photo-detectors, and quantum-computers. Consequently, the absence of an established universal relationships between critical temperature (TcT_c), film thickness (dd) and sheet resistance (RsR_s) hinders both our understanding of the onset of the superconductivity and the development of miniaturised superconducting devices. We report that in thin films, superconductivity scales as d.d^.Tc(Rs)T_c(R_s). We demonstrated this scaling by analysing the data published over the past 46 years for different materials (and facilitated this database for further analysis). Moreover, we experimentally confirmed the discovered scaling for NbN films, quantified it with a power law, explored its possible origin and demonstrated its usefulness for superconducting film-based devices.Comment: 100 pages, 37 figure

    Clinical characteristics and prognosis of cardiac amyloidosis defined by mass spectrometry-based proteomics in an Australian cohort.

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    Cardiac amyloidosis has a very poor prognosis, but it is the nature of the involved precursor protein that ultimately dictates treatment and survival. We report the clinical characteristics and survival of 47 cardiac amyloid patients across 2 Australian centres including 39 patients evaluated for definitive amyloid subtype utilising laser microdissection and tandem mass spectrometry (LMD-MS). A quarter of patients (n=12) were classified as wild type transthyretin amyloidosis (ATTRwt), 33 patients as light or heavy chain amyloidosis (AL or AH), and 2 as hereditary mutant transthyretin amyloidosis (ATTRv). Greater left ventricular hypertrophy (IV septum 22 vs. 15 mm, p=0.005) and history of cardiac arrhythmia (75% vs. 31%, p=0.016) were significantly associated with ATTRwt patients compared with AL/AH patients. AL patients demonstrated significantly shorter median survival compared to ATTRwt patients (3.5 vs. 37 months, (P=0.007)). New York heart association (NYHA) class III-IV symptoms or plasma cells ≥ 10% at diagnosis, were the only independent predictors of worse survival in AL patients on multivariate analysis. In the era of novel therapies for both AL amyloid and ATTR, identification of the correct amyloid subtype is essential in making therapeutic decisions and providing accurate prognostic information to patients. This article is protected by copyright. All rights reserved
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