Distinguishing d-wave from highly anisotropic s-wave superconductors

Systematic impurity doping in the Cu-O plane of the hole-doped cuprate superconductors may allow one to decide between unconvention al ("d-wave") and anisotropic conventional ("s-wave") states as possible candidates for the order parameter in these materials. We show that potential scattering of any strength always increases the gap minima of such s-wave states, leading to activated behavior in temperature with characteristic impurity concentration dependence in observable quantities such as the penetration depth. A magnetic component to the scattering may destroy the energy gap and give rise to conventional gapless behavior, or lead to a nonmonotonic dependence of the gap on impurity concentration. We discuss how experiments constrain this analysis.Comment: 5 page

Heart failure events in randomized controlled trials for adults receiving maintenance dialysis: a meta-epidemiologic study

Background and hypothesis: Heart failure is characterized as cardiac dysfunction resulting in elevated cardiac filling pressures with symptoms and signs of congestion. Distinguishing heart failure from other causes of similar presentations in patients with kidney failure is challenging but necessary, and is needed in randomized controlled trials (RCTs) to accurately estimate treatment effects. The objective of this study was to review heart failure events, their diagnostic criteria and adjudication in RCTs of patients with kidney failure treated with dialysis. We hypothesized that heart failure events, diagnostic criteria and adjudication were infrequently reported in RCTs in dialysis. Methods: We conducted a meta-epidemiologic systematic review of RCTs from high impact medical, nephrology and cardiology journals from 2000 to 2020. RCTs were eligible if they enrolled adults receiving maintenance dialysis for kidney failure and evaluated any intervention. Results. Of 561 RCTs in patients receiving dialysis, 36 (6.4%) reported heart failure events as primary (10, 27.8%) or secondary (31, 86.1%) outcomes. 10 of the 36 (27.8%) RCTs provided heart failure event diagnostic criteria and 5 of these 10 (50%) adjudicated heart failure events. These 10 RCTs included event diagnostic criteria for heart failure or heart failure hospitalizations, and their criteria included dyspnea (5/10), edema (2/10), rales/crackles (4/10), chest x-ray pulmonary edema or vascular redistribution (4/10), treatment in an acute setting (6/10) and ultrafiltration or dialysis (4/10). No study explicitly distinguished heart failure from volume overload secondary to non-adherence or underdialysis. Conclusion: Overall, we found that heart failure events are infrequently reported in RCTs in dialysis and are heterogeneously defined. Further research is required to develop standardized diagnostic criteria that are practical and meaningful to patients and clinicians

Myocardial Infarction in Major Noncardiac Surgery: Epidemiology, Pathophysiology and Prevention

The number of subjects undergoing major noncardiac surgery who are at risk for perioperative myocardial infarction (MI) is growing worldwide. It has been estimated that 500,000 to 900,000 patients suffer major perioperative cardiovascular complications every year, with consequent heavy, long-term prognostic implications and costs. It is well known that perioperative MIs don’t share the same pathophysiology as nonsurgical MIs but the relative role of the different, potential triggers has not been completely clarified. Many aspects of the perioperative management, including risk-stratification and prophylactic or postoperative interventions have also not been completely defined. Throughout recent years many resources have been invested to clarify these aspects and experts have developed indices and algorithm-based strategies to better assess the cardiac risk and to guide the perioperative management. The scope of the present review is to discuss the main aspects of perioperative MI in noncardiac surgery, with particular regard to epidemiology, pathophysiology, preoperative risk stratification, prophylaxis and therapy