232 research outputs found

    Cu NMR Study of Detwinned Single Crystals of Ortho--II YBCO6.5

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    Copper NMR has been used as a local probe of the oxygen ordering in Ortho--II YBa2Cu3O6.5 crystals grown in BaZrO3 crucibles. Line assignments have been made to each of the expected crystallographically inequivalent sites. The presence of distinct and narrow lines for these sites as well as the lack of a line known to be associated with oxygen defects indicates that these crystals are highly stoichiometric. Our estimate of the lower limit on the chain length is consistent with that derived from X-ray diffraction measurements. In addition, we have found no evidence for static magnetic moments, in contrast to some previous results.Comment: 11 pages, 7 figures, submitted to Physica

    Concerning Order and Disorder in the Ensemble of Cu-O Chain Fragments in Oxygen Deficient Planes of Y-Ba-Cu-O

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    In connection with numerous X-ray and neutron investigations of some high temperature superconductors (YBa2_2Cu3_3O6+x_{6+x} and related compounds) a non-trivial part of the structure factor, coming from partly disordered Cu-O-\dots-O-Cu chain fragments, situated within basal planes, CuOx_x, can be a subject of theoretical interest. Closely connected to such a diffusive part of the structure factor are the correlation lengths, which are also available in neutron and X-ray diffraction studies and depend on a degree of oxygen disorder in a basal plane. The quantitative measure of such a disorder can be associated with temperature of a sample anneal, TqT_q, at which oxygen in a basal plane remains frozen-in high temperature equilibrium after a fast quench of a sample to room or lower temperature. The structure factor evolution with xx is vizualized in figures after the numerical calculations. The theoretical approach employed in the paper has been developed for the orthorhombic state of YBCO.Comment: Revtex, 27 pages, 14 PostScript figures upon request, ITP/GU/94/0

    Peristomal Skin Complications Are Common, Expensive, and Difficult to Manage: A Population Based Cost Modeling Study

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    BACKGROUND: Peristomal skin complications (PSCs) are the most common post-operative complications following creation of a stoma. Living with a stoma is a challenge, not only for the patient and their carers, but also for society as a whole. Due to methodological problems of PSC assessment, the associated health-economic burden of medium to longterm complications has been poorly described. AIM: The aim of the present study was to create a model to estimate treatment costs of PSCs using the standardized assessment Ostomy Skin Tool as a reference. The resultant model was applied to a real-life global data set of stoma patients (n = 3017) to determine the prevalence and financial burden of PSCs. METHODS: Eleven experienced stoma care nurses were interviewed to get a global understanding of a treatment algorithm that formed the basis of the cost analysis. The estimated costs were based on a seven week treatment period. PSC costs were estimated for five underlying diagnostic categories and three levels of severity. The estimated treatment costs of severe cases of PSCs were increased 2-5 fold for the different diagnostic categories of PSCs compared with mild cases. French unit costs were applied to the global data set. RESULTS: The estimated total average cost for a seven week treatment period (including appliances and accessories) was 263€ for those with PSCs (n = 1742) compared to 215€ for those without PSCs (n = 1172). A co-variance analysis showed that leakage level had a significant impact on PSC cost from 'rarely/never' to 'always/often' p<0.00001 and from 'rarely/never' to 'sometimes' p = 0.0115. CONCLUSION: PSCs are common and troublesome and the consequences are substantial, both for the patient and from a health economic viewpoint. PSCs should be diagnosed and treated at an early stage to prevent long term, debilitating and expensive complications

    Do Multidisciplinary Team (MDT) processes influence survival in patients with colorectal cancer? A population-based experience

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    BACKGROUND: MDT (multidisciplinary team) meetings are considered an essential component of care for patients with cancer. However there is remarkably little direct evidence that such meetings improve outcomes. We assessed whether or not MDT (multidisciplinary team) processes influenced survival in a cohort of patients with colorectal cancer. METHODS: Observational study of a population-based cohort of 586 consecutive patients with colorectal cancer diagnosed in Tayside (Scotland) during 2006 and 2007. RESULTS: Recommendations from MDT meetings were implemented in 411/586 (70.1 %) of patients, the MDT+ group. The remaining175/586 (29.9 %) were either never discussed at an MDT, or recommendations were not implemented, MDT- group. The 5-year cause-specific survival (CSS) rates were 63.1 % (MDT+) and 48.2 % (MDT-), p < 0.0001. In analysis confined to patients who survived >6 weeks after diagnosis, the rates were 63.2 % (MDT+) and 57.7 % (MDT-), p = 0.064. The adjusted hazard rate (HR) for death from colorectal cancer was 0.73 (0.53 to 1.00, p = 0.047) in the MDT+ group compared to the MDT- group, in patients surviving >6 weeks the adjusted HR was 1.00 (0.70 to 1.42, p = 0.987). Any benefit from the MDT process was largely confined to patients with advanced disease: adjusted HR ((early)) 1.32 (0.69 to 2.49, p = 0.401); adjusted HR((advanced)) 0.65 (0.45 to 0.96, p = 0.031). CONCLUSIONS: Adequate MDT processes are associated with improved survival for patients with colorectal cancer. However, some of this effect may be more apparent than real – simply reflecting selection bias. The MDT process predominantly benefits the 40 % of patients who present with advanced disease and conveys little demonstrable advantage to patients with early tumours. These results call into question the current belief that all new patients with colorectal cancer should be discussed at an MDT meeting

    Systematic review of patient preference and adherence to the correct use of graduated compression stockings to prevent deep vein thrombosis in surgical patients

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    Aim: To explore patient preference and adherence to thigh and knee length graduated compression stockings for the prevention of deep vein thrombosis in surgical patients. Background: Hospitalised patients are at risk of developing deep vein thrombosis. Mechanical methods of prophylaxis include compression stockings, available as knee or thigh length. Patient adherence to correct stocking use is of critical importance to their effectiveness. Design: Systematic review of quantitative evidence. Data sources: Eleven databases were searched from inception to 2013 for systematic reviews of compression stockings. Reviews were screened for relevant primary studies and update searches of eight electronic sources were undertaken (2010-2014). Review methods: Randomised controlled trials and observational studies of surgical patients using compression stockings were quality assessed and data were extracted on patient adherence and preference. A narrative summary is presented. Results: Nine randomised controlled trials and seven observational studies were included in the systematic review. There was substantial variation between studies in terms of patient characteristics, interventions and methods of outcome assessment. Conclusion: Patient adherence was generally higher with knee length than thigh length stockings. However, the studies reflect patient adherence in a hospital setting only, where patients are observed by healthcare professionals; it is likely that adherence reduces once patients have been discharged from hospital. Patients preferred knee length stockings over thigh length stockings. In many clinical settings any difference in efficacy between thigh length and knee length stockings may be rendered irrelevant by patient preference for and likely better adherence to knee length stockings
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