Green function techniques in the treatment of quantum transport at the molecular scale

The theoretical investigation of charge (and spin) transport at nanometer length scales requires the use of advanced and powerful techniques able to deal with the dynamical properties of the relevant physical systems, to explicitly include out-of-equilibrium situations typical for electrical/heat transport as well as to take into account interaction effects in a systematic way. Equilibrium Green function techniques and their extension to non-equilibrium situations via the Keldysh formalism build one of the pillars of current state-of-the-art approaches to quantum transport which have been implemented in both model Hamiltonian formulations and first-principle methodologies. We offer a tutorial overview of the applications of Green functions to deal with some fundamental aspects of charge transport at the nanoscale, mainly focusing on applications to model Hamiltonian formulations.Comment: Tutorial review, LaTeX, 129 pages, 41 figures, 300 references, submitted to Springer series "Lecture Notes in Physics

Prognostic value of adenosine stress cardiovascular magnetic resonance in patients with low-risk chest pain

<p>Abstract</p> <p>Background</p> <p>Approximately 5% of patients with an acute coronary syndrome are discharged from the emergency room with an erroneous diagnosis of non-cardiac chest pain. Highly accurate non-invasive stress imaging is valuable for assessment of low-risk chest pain patients to prevent these errors. Adenosine stress cardiovascular magnetic resonance (AS-CMR) is an imaging modality with increasing application. The goal of this study was to evaluate the negative prognostic value of AS-CMR among low-risk acute chest pain patients.</p> <p>Methods</p> <p>We studied 103 patients, mean 56.7 ± 12.3 years of age, with chest pain and no electrocardiographic evidence of ischemia and negative cardiac biomarkers of necrosis, who were admitted to the Cardiac Decision Unit of our institution. All patients underwent AS-CMR. A negative AS-CMR was defined as absence of all the following: regional wall motion abnormalities at rest; perfusion defects during stress (adenosine) and rest; and myocardial scar on late gadolinium enhancement images. The patients were followed for a mean of 277 (range 161-462) days. The primary end point was defined as the combination of cardiac death, nonfatal acute myocardial infarction, re-hospitalization for chest pain, obstructive coronary artery disease (>50% coronary stenosis on invasive angiography) and coronary revascularization.</p> <p>Results</p> <p>In 14 patients (13.6%), AS-CMR was positive. The remaining 89 patients (86.4%), who had negative AS-CMR, were discharged. No patient with negative AS-CMR reached the primary end-point during follow-up. The negative predictive value of AS-CMR was 100%.</p> <p>Conclusion</p> <p>AS-CMR holds promise as a useful tool to rule out significant coronary artery disease in patients with low-risk chest pain. Patients with negative AS-CMR have an excellent short and mid-term prognosis.</p

Case management used to optimize cancer care pathways: A systematic review

<p>Abstract</p> <p>Background</p> <p>Reports of inadequate cancer patient care have given rise to various interventions to support cancer care pathways which, overall, seem poorly studied. Case management (CM) is one method that may support a cost-effective, high-quality patient-centred treatment and care.</p> <p>The purpose of this article was to summarise intervention characteristics, outcomes of interest, results, and validity components of the published randomized controlled trials (RCTs) examining CM as a method for optimizing cancer care pathways.</p> <p>Methods</p> <p>PubMed, Embase, Web of Science, CINAHL and The Cochrane Central Register of Controlled Trials were systematically searched for RCTs published all years up to August 2008. Identified papers were included if they passed the following standards. Inclusion criteria: 1) The intervention should meet the criteria for CM which includes multidisciplinary collaboration, care co-ordination, and it should include in-person meetings between patient and the case manager aimed at supporting, informing and educating the patient. 2) The intervention should focus on cancer patient care. 3) The intervention should aim to improve subjective or objective quality outcomes, and effects should be reported in the paper.</p> <p>Exclusion criteria: Studies centred on cancer screening or palliative cancer care.</p> <p>Data extraction was conducted in order to obtain a descriptive overview of intervention characteristics, outcomes of interest and findings. Elements of CONSORT guidelines and checklists were used to assess aspects of study validity.</p> <p>Results</p> <p>The searches identified 654 unique papers, of which 25 were retrieved for scrutiny. Seven papers were finally included. Intervention characteristics, outcomes studied, findings and methodological aspects were all very diverse.</p> <p>Conclusion</p> <p>Due to the scarcity of papers included (seven), significant heterogeneity in target group, intervention setting, outcomes measured and methodologies applied, no conclusions can be drawn about the effect of CM on cancer patient care.</p> <p>It is a major challenge that CM shrouds in a "black box", which means that it is difficult to determine which aspect(s) of interventions contribute to overall effects. More trials on rigorously developed CM interventions (opening up the "black box") are needed as is the re-testing of interventions and outcomes studied in various settings.</p

Assessment of acute myocardial infarction: current status and recommendations from the North American society for cardiovascular imaging and the European society of cardiac radiology

There are a number of imaging tests that are used in the setting of acute myocardial infarction and acute coronary syndrome. Each has their strengths and limitations. Experts from the European Society of Cardiac Radiology and the North American Society for Cardiovascular Imaging together with other prominent imagers reviewed the literature. It is clear that there is a definite role for imaging in these patients. While comparative accuracy, convenience and cost have largely guided test decisions in the past, the introduction of newer tests is being held to a higher standard which compares patient outcomes. Multicenter randomized comparative effectiveness trials with outcome measures are required

2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation: executive summary.

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