Semiclassical time--dependent propagation in three dimensions: How accurate is it for a Coulomb potential?

A unified semiclassical time propagator is used to calculate the semiclassical time-correlation function in three cartesian dimensions for a particle moving in an attractive Coulomb potential. It is demonstrated that under these conditions the singularity of the potential does not cause any difficulties and the Coulomb interaction can be treated as any other non-singular potential. Moreover, by virtue of our three-dimensional calculation, we can explain the discrepancies between previous semiclassical and quantum results obtained for the one-dimensional radial Coulomb problem.Comment: 8 pages, 4 figures (EPS

Penumbra indigo percutaneous aspiration thrombectomy system in the treatment of aortic endograft iliac limb occlusion: results from an Italian Multicentre Registry

Objective: This study aimed to evaluate the safety and effectiveness of the Penumbra Indigo percutaneous aspiration thrombectomy (PAT) system in the clinical presentation of iliac limb occlusion (ILO) after endovascular aortic repair (EVAR).Methods: A retrospective, observational, multicentre study conducted in eight Italian vascular centres. Consecutive patients presenting with ILO after EVAR were eligible. To assess vessel revascularisation, Thrombo-aspiration In Peripheral Ischaemia (TIPI) classification (score 0-3) was used at presentation (t1), after PAT (t2), and after adjunctive procedures (t3). Successful revascularisation was considered TIPI 2-3 (near complete or complete). Primary intra-operative outcomes were technical success (TS) of Indigo PAT and combined TS of PAT associated with adjunctive procedures when needed. Primary follow up outcomes were safety and effectiveness at one, six, and 12 months.Results: From September 2019 to December 2021, there were 48 ILO and 17 patients (35%) [median age 75 years, IQR 71, 83 years; male, 14 (82%); urgent, 8 (47%)] were treated and enrolled. The median time after primary EVAR was 24 months (IQR 0, 42 months). The median clot age from ILO diagnosis to PAT was three days (IQR 1, 12 days). Ten patients (59%) presented with limb threatening ischaemia. At t1, TIPI 0 and 1 was present in 13 (76%) and four (24%) cases, respectively. At t2, primary TS (TIPI 2-3) was achieved in 14 cases (82%) after Indigo PAT (p < .001). Fifteen patients (88%) required adjunctive procedures (14 re-linings, one surgical patch angioplasty). At t3, combined TS was achieved in 16 cases (94%). Intra-operative complication included one (6%) distal embolisation, treated successfully. The 30 day mortality was one case (6%) due to pneumonia. At one, six, and 12 months, clinical success was 100% without ILO recurrence. The median follow up was 23 months (IQR 11, 41 months): at 18 months, survival and freedom from re-intervention were 91 + 8% and 90 + 9%, respectively.Conclusion: This study reports for the first time the efficacy and safety of Penumbra Indigo PAT for ILO after EVAR, with promising technical and clinical success up to one year

Ferumoxytol-enhanced magnetic resonance imaging in acute myocarditis

Objectives Ultrasmall superparamagnetic particles of iron oxide (USPIO)-enhanced MRI can detect tissue-resident macrophage activity and identify cellular inflammation within tissues. We hypothesised that USPIO-enhanced MRI would provide a non-invasive imaging technique that would improve the diagnosis and management of patients with acute myocarditis. Methods Ten volunteers and 14 patients with suspected acute myocarditis underwent T2, T2* and late gadolinium enhancement (LGE) 3T MRI, with further T2* imaging at 24 hours after USPIO (ferumoxytol, 4 mg/kg) infusion, at baseline and 3 months. Myocardial oedema and USPIO enhancement were determined within areas of LGE as well as throughout the myocardium. Results Myocarditis was confirmed in nine of the 14 suspected cases of myocarditis. There was greater myocardial oedema in regions of LGE in patients with myocarditis when compared with healthy volunteer myocardium (T2 value, 57.1±5.3 vs 46.7±1.6 ms, p0.05). Imaging after 3 months in patients with myocarditis revealed a reduction in volume of LGE, a reduction in oedema measures within regions displaying LGE and improvement in ejection fraction (mean −19.7 mL, 95% CI (−0.5 to −40.0)), −5.8 ms (−0.9 to −10.7) and +6% (0.5% to 11.5%), respectively, p<0.05 for all). Conclusion In patients with acute myocarditis, USPIO-enhanced MRI does not provide additional clinically relevant information to LGE and T2 mapping MRI. This suggests that tissue-resident macrophages do not provide a substantial contribution to the myocardial inflammation in this condition. Clinical trial registration NCT02319278; Results

An evaluation of metal removal during wastewater treatment: The potential to achieve more stringent final effluent standards

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2011 Taylor & Francis.Metals are of particular importance in relation to water quality, and concern regarding the impact of these contaminants on biodiversity is being encapsulated within the latest water-related legislation such as the Water Framework Directive in Europe and criteria revisions to the Clean Water Act in the United States. This review undertakes an evaluation of the potential of 2-stage wastewater treatment consisting of primary sedimentation and biological treatment in the form of activated sludge processes, to meet more stringent discharge consents that are likely to be introduced as a consequence. The legislation, sources of metals, and mechanisms responsible for their removal are discussed, to elucidate possible pathways by which the performance of conventional processes may be optimized or enhanced. Improvements in effluent quality, achievable by reducing concentrations of suspended solids or biochemical oxygen demand, may also reduce metal concentrations although meeting possible requirements for the removal of copper my be challenging

Quantification of macrophage-driven inflammation during myocardial infarction with 18F-LW223, a novel TSPO radiotracer with binding independent of the rs6971 human polymorphism

Myocardial infarction (MI) is one of the leading causes of death worldwide, and inflammation is central to tissue response and patient outcomes. The 18-kDa translocator protein (TSPO) has been used in PET as an inflammatory biomarker. The aims of this study were to screen novel, fluorinated, TSPO radiotracers for susceptibility to the rs6971 genetic polymorphism using in vitro competition binding assays in human brain and heart; assess whether the in vivo characteristics of our lead radiotracer, 18F-LW223, are suitable for clinical translation; and validate whether 18F-LW223 can detect macrophage-driven inflammation in a rat MI model. Methods: Fifty-one human brain and 29 human heart tissue samples were screened for the rs6971 polymorphism. Competition binding assays were conducted with 3H-PK11195 and the following ligands: PK11195, PBR28, and our novel compounds (AB5186 and LW223). Naïve rats and mice were used for in vivo PET kinetic studies, radiometabolite studies, and dosimetry experiments. Rats underwent permanent coronary artery ligation and were scanned using PET/CT with an invasive input function at 7 d after MI. For quantification of PET signal in the hypoperfused myocardium, K1 (rate constant for transfer from arterial plasma to tissues) was used as a surrogate marker of perfusion to correct the binding potential for impaired radiotracer transfer from plasma to tissue (BPTC). Results: LW223 binding to TSPO was not susceptible to the rs6971 genetic polymorphism in human brain and heart samples. In rodents, 18F-LW223 displayed a specific uptake consistent with TSPO expression, a slow metabolism in blood (69% of parent at 120 min), a high plasma free fraction of 38.5%, and a suitable dosimetry profile (effective dose of 20.5–24.5 μSv/MBq). 18F-LW223 BPTC was significantly higher in the MI cohort within the infarct territory of the anterior wall relative to the anterior wall of naïve animals (32.7 ± 5.0 vs. 10.0 ± 2.4 cm3/mL/min, P ≤ 0.001). Ex vivo immunofluorescent staining for TSPO and CD68 (macrophage marker) resulted in the same pattern seen with in vivo BPTC analysis. Conclusion: 18F-LW223 is not susceptible to the rs6971 genetic polymorphism in in vitro assays, has favorable in vivo characteristics, and is able to accurately map macrophage-driven inflammation after MI