3,364 research outputs found
Kondo effect in a one dimensional d-wave superconductor
We derive a solvable resonant-level type model, to describe an impurity spin
coupled to zero-energy bound states localized at the edge of a one dimensional
d-wave superconductor. This results in a two-channel Kondo effect with a quite
unusual low-temperature thermodynamics. For instance, the local impurity
susceptibility yields a finite maximum at zero temperature (but no
logarithmic-divergence) due to the splitting of the impurity in two Majorana
fermions. Moreover, we make comparisons with the Kondo effect occurring in a
two dimensional d-wave superconductor.Comment: 9 pages, final version; To be published in Europhysics Letter
Disease severity adversely affects delivery of dialysis in acute renal failure
Background/Aims: Methods of intermittent hemodialysis (IHD) dose quantification in acute renal failure (ARF) are not well defined. This observational study was designed to evaluate the impact of disease activity on delivered single pool Kt/V-urea in ARF patients. Methods: 100 patients with severe ARF (acute intrinsic renal disease in 18 patients, nephrotoxic acute tubular necrosis in 38 patients, and septic ARF in 44 patients) were analyzed during four consecutive sessions of IHD, performed for 3.5-5 h every other day or daily. Target IHD dose was a single pool Kt/V-urea of 1.2 or more per dialysis session for all patients. Prescribed Kt/V-urea was calculated from desired dialyzer clearance (K), desired treatment time (t) and anthropometric estimates for urea distribution volume (V). The desired clearance (K) was estimated from prescribed blood flow rate and manufacturer's charts of in vivo data obtained in maintenance dialysis patients. Delivered single pool Kt/V-urea was calculated using the Daugirdas equation. Results: None of the patients had prescription failure of the target dose. The delivered IHD doses were substantially lower than the prescribed Kt/V values, particularly in ARF patients with sepsis/septic shock. Stratification according to disease severity revealed that all patients with isolated ARF, but none with 3 or more organ failures and none who needed vasopressive support received the target dose. Conclusion: Prescription of target IHD dose by single pool Kt/V-urea resulted in suboptimal dialysis dose delivery in critically ill patients. Numerous patient-related and treatment-immanent factors acting in concert reduced the delivered dose. Copyright (C) 2007 S. Karger AG, Basel
Hydroxymethylglutaryl-CoA reductase inhibition with simvastatin in acute lung injury to reduce pulmonary dysfunction (HARP-2) trial : study protocol for a randomized controlled trial
Acute lung injury (ALI) is a common devastating clinical syndrome characterized by life-threatening respiratory failure requiring mechanical ventilation and multiple organ failure. There are in vitro, animal studies and pre-clinical data suggesting that statins may be beneficial in ALI. The Hydroxymethylglutaryl-CoA reductase inhibition with simvastatin in Acute lung injury to Reduce Pulmonary dysfunction (HARP-2) trial is a multicenter, prospective, randomized, allocation concealed, double-blind, placebo-controlled clinical trial which aims to test the hypothesis that treatment with simvastatin will improve clinical outcomes in patients with ALI
Effect of individual patient risk, centre, surgeon and anaesthetist on length of stay in hospital after cardiac surgery: Association of Cardiothoracic Anaesthesia and Critical Care (ACTACC) consecutive cases series study of 10 UK specialist centres.
OBJECTIVES: To determine the relative contributions of patient risk profile, local and individual clinical practice on length of hospital stay after cardiac surgery. DESIGN: Ten-year audit of prospectively collected consecutive cardiac surgical cases. Case-mix adjusted outcomes were analysed in models that included random effects for centre, surgeon and anaesthetist. SETTING: UK centres providing adult cardiac surgery. PARTICIPANTS: 10 of 36 UK specialist centres agreed to provide outcomes for all major cardiac operations over 10 years. After exclusions (duplicates, cases operated by more than one consultant, deaths and procedures for which the EuroSCORE risk score for cardiac surgery is not appropriate), there were 107 038 cardiac surgical procedures between April 2002 and March 2012, conducted by 127 consultant surgeons and 190 consultant anaesthetists. MAIN OUTCOME MEASURE: Length of stay (LOS) up to 3 months postoperatively. RESULTS: The principal component of variation in outcomes was patient risk (represented by the EuroSCORE and remaining patient heterogeneity), accounting for 95.43% of the variation for postoperative LOS. The impact of the surgeon and centre was moderate (intra-class correlation coefficients ICC=2.79% and 1.59%, respectively), whereas the impact of the anaesthetist was negligible (ICC=0.19%). Similarly, 96.05% of the variation for prolonged LOS (>11 days) was attributable to the patient, with surgeon and centre less but still influential components (ICC=2.12% and 1.66%, respectively, 0.17% only for anaesthetists). Adjustment for year of operation resulted in minor reductions in variation attributable to surgeons (ICC=2.52% for LOS and 2.23% for prolonged LOS). CONCLUSIONS: Patient risk profile is the primary determinant of variation in LOS, and as a result, current initiatives to reduce hospital stay by modifying consultant performance are unlikely to have a substantial impact. Therefore, substantially reducing hospital stay requires shifting away from a one-size-fits-all approach to cardiac surgery, and seeking alternative treatment options personalised to high-risk patients
The ethics of distress: Toward a framework for determining the ethical acceptability of distressing health promotion advertising
© 2014 International Union of Psychological Science. Distressing health promotion advertising involves the elicitation of negative emotion to increase the likelihood that health messages will stimulate audience members to adopt healthier behaviors. Irrespective of its effectiveness, distressing advertising risks harming audience members who do not consent to the intervention and are unable to withdraw from it. Further, the use of these approaches may increase the potential for unfairness or stigmatization toward those targeted, or be considered unacceptable by some sections of the public. We acknowledge and discuss these concerns, but, using the public health ethics literature as a guide, argue that distressing advertising can be ethically defensible if conditions of effectiveness, proportionality necessity, least infringement, and public accountability are satisfied. We do not take a broad view as to whether distressing advertising is ethical or unethical, because we see the evidence for both the effectiveness of distressing approaches and their potential to generate iatrogenic effects to be inconclusive. However, we believe it possible to use the current evidence base to make informed estimates of the likely consequences of specific message presentations. Messages can be pre-tested and monitored to identify and deal with potential problems. We discuss how advertisers can approach the problems of deciding on the appropriate intensity of ethical review, and evaluating prospective distressing advertising campaigns against the conditions outlined
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