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Measurements and simulations show that plasma relaxation processes in the reversed field pinch drive and redistribute both magnetic flux and momentum. To examine this relaxation process, a new 3D Mach B-dot probe has been constructed. This probe collects ion saturation currents through six molybdenum electrodes arranged on the flattened vertices of an octahedron made of boron nitride (BN). The ion saturation current flows through configurable voltage dividers for measurement and returns through one of six selectable return electrodes equally spaced along the 12 cm BN probe arm. In addition, the probe arm houses three B-dot magnetic pickup coils in the BN stalk immediately below to the octahedron, to measure the local magnetic field. Inserted in the Madison Symmetric Torus (MST) during deuterium discharges with 220 kA plasma current, density of 0.8 × 1013 cm−3, the probe collects ion saturation currents with sawtooth-like peaks correlated with relaxation events. This compact octahedral design fitting six Mach electrode surfaces within a 1 cm3 cube will enable future multi-point, multi-field probes compatible with the 1.5 in. ports of MST. Such probes will allow for flow circulation, current, and canonical vorticity to be calculated in the center of the finite difference stencil formed by the measurement locations. [ABSTRACT FROM AUTHOR]

We demonstrate the efficient injection of a pulsed positron beam into a magnetic dipole trap and investigate the ensuing particle dynamics in the inhomogeneous electric and magnetic fields. Bunches of ∼10^{5}e^{+} were transferred from a buffer-gas trap into the field of a permanent magnet using a lossless E×B drift technique. The Δt≈0.2µs pulses were short compared to the toroidal rotation period, τ_{d}≈16µs, and e^{+} confinement time, τ_{c}≈0.6 s. The redistribution dynamics were studied by measuring the delayed γ-ray emission as the trap was emptied. This work extends the record for the number of low-energy positrons held in a dipole trap by two orders of magnitude and represents a significant advance toward the confinement of an electron-positron pair plasma.

When using rapid deployment surgical aortic valve replacement (RD SAVR) in treating bicuspid aortic valve morphology (BAV), several challenges are faced due to annular asymmetry. The Sievers classification has been traditionally used for the description of BAV morphology. In this study, we aimed to conduct a retrospective feasibility analysis of RD SAVR in relation to the Sievers classification. From January 2014 to March 2022, 31 patients with BAV morphology (15 patients with Sievers type 0 BAV and 16 with Sievers type 1 BAV) underwent RD SAVR. Specific surgical techniques were applied depending on the BAV morphology. Comparable clinical outcomes were observed. No paravalvular leaks and no valvular re-interventions occurred in either group. CPB and cross-clamping times, as well as the prosthesis sizes used, were also not significantly different. Postoperative mean gradients were comparable in both groups. No significant distinction was found between the groups in terms of postoperative pacemaker indication, postoperative stroke, or death. Annular symmetry can be adequately restored through precise prosthesis sizing and placement according to an individual's valve morphology regardless of the Sievers classification of BAV by choosing a different landmark for the initial suture. RD SAVR seems to be a safe approach for any bicuspid morphology, with good hemodynamic results and time-saving potential in experienced hands.

Background: Although the incidence of stroke in the young is rising, data on long-term outcomes in these patients are scarce. We thus aimed to investigate the long-term risk of recurrent vascular events and mortality in a multicenter study., Methods: We followed 396 consecutive patients aged 18-55 years with ischemic stroke (IS) or transient ischemic attack (TIA) enrolled in three European centers during the period 2007-2010. A detailed outpatient clinical follow-up assessment was performed between 2018 and 2020. When an in-person follow-up visit was not possible, outcome events were assessed using electronic records and registry data., Results: During a median follow-up of 11.8 (IQR 10.4-12.7) years, 89 (22.5%) patients experienced any recurrent vascular event, 62 (15.7%) had any cerebrovascular event, 34 (8.6%) had other vascular events, and 27 (6.8%) patients died. Cumulative 10-year incidence rate per 1000 person-years was 21.6 (95% CI 17.1-26.9) for any recurrent vascular event and 14.9 (95% CI 11.3-19.3) for any cerebrovascular event. The prevalence of cardiovascular risk factors increased over time, and 22 (13.5%) patients lacked any secondary preventive medication at the in-person follow-up. After adjustment for demographics and comorbidities, atrial fibrillation at baseline was found to be significantly associated with recurrent vascular events., Conclusions: This multicenter study shows a considerable risk of recurrent vascular events in young IS and TIA patients. Further studies should investigate whether detailed individual risk assessment, modern secondary preventive strategies, and better patient adherence may reduce recurrence risk., (© 2023 The Authors. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.)

Background: We analyzed the short-term and mid-term outcomes as well as the health-related quality of life (HRQOL) of octogenarians undergoing elective and urgent cardiac surgery., Patients and Methods: We retrospectively identified 688 consecutive octogenarians who underwent cardiac surgery at our center between January 2012 and December 2019. A propensity score matching was performed which resulted in the formation of 80 matched pairs. The patients were interviewed and the Short Form-36 survey was used to assess the HRQOL of survivors. Multivariable analysis incorporated binary logistic regression using a forward stepwise (conditional) model., Results: The median age of the matched cohort was 82 years ( p  = 0.937), among whom, 38.8% of patients were female ( p  = 0.196). The median EuroSCORE II of the matched cohort was 19.4% (10.1-39.1%). The duration of postoperative mechanical ventilation was found to be independently associated with in-hospital mortality (odds ratio: 1.01 [95% confidence interval: 1.0-1.02], p  = 0.038). The survival rates at 1, 2, and 5 years was 75.0, 72.0, and 46.0%, respectively. There was no difference in the total survival between the groups ( p  = 0.080). The physical health summary score was 41 (30-51) for the elective patients and 42 (35-49) for the nonelective octogenarians ( p  = 0.581). The median mental health summary scores were 56 (48-60) and 58 (52-60), respectively ( p  = 0.351)., Conclusion: Cardiac surgery can be performed in octogenarians with good results and survivors enjoy a good quality of life; however, the indication for surgery or especially for escalation of therapy should always be made prudently, reserved, and in consideration of patient expectations., Competing Interests: None declared., (Thieme. All rights reserved.)

Objectives: The aim of this study was to evaluate the surgical outcome of patients suffering from native aortic valve (NVE) or prosthetic aortic valve endocarditis (PVE) treated with the EDWARDS INTUITY Elite rapid-deployment valve prosthesis., Methods: Between February 2019 and June 2020, 25 patients suffering from NVE (n = 9; 36%) and PVE (n = 16; 64%) of the aortic valve received an INTUITY valve at our institution. Preoperative, operative and follow-up data were collected., Results: In our cohort, the mean EuroSCORE II was 13.4%. Eleven patients (44%) received concomitant aortic root patch plasty. Four patients (16%) received coronary artery bypass graft surgery, 3 patients (12%) received mitral valve repair and 2 patients (8%) underwent replacement of the ascending aorta. The cardiopulmonary bypass and aortic cross-clamp times were 124 ± 56 and 75 ± 39 min, respectively. The mean intensive care unit stay was 5 days. The mean size of the implanted prostheses was 25 ± 2 mm and the mean prosthesis transvalvular gradient 3 months after surgery was 9 ± 4 mmHg. During follow-up, no case of recurrent endocarditis occurred, 1 patient died of multisystem organ failure which had already been present preoperatively., Conclusions: Surgery for NVE and PVE of the aortic valve may be safely performed using the EDWARDS INTUITY Elite valve system. This procedure could be well implemented in cases with extensive infection, fragile root tissue and root abscesses requiring root reconstruction. In our institution, the rapid-deployment aortic valve replacement strategy has become an important tool in the armamentarium of the surgical endocarditis treatment., (© The Author(s) 2022. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Electron-positron pairs, produced in intense laser-solid interactions, are diagnosed using magnetic spectrometers with image plates, such as the National Ignition Facility Electron-Positron-Proton Spectrometers (EPPSs). Although modeling can help infer the quantitative value, the accuracy of the models needs to be verified to ensure measurement quality. The dispersion of low-energy electrons and positrons may be affected by fringe magnetic fields near the entrance of the EPPS. We have calibrated the EPPS with six electron beams from a Siemens Oncor linear accelerator (linac) ranging in energy from 2.7 MeV to 15.2 MeV as they enter the spectrometer. A Geant4 traveling-wave optical parametric amplifier of superfluorescence Monte Carlo simulation was set up to match depth dose curves and lateral profiles measured in water at 100 cm source-surface distance. An accurate relationship was established between the bending magnet current setting and the energy of the electron beam at the exit window. The simulations and measurements were used to determine the energy distributions of the six electron beams at the EPPS slit. Analysis of the scanned image plates together with the determined energy distribution arriving in the spectrometer provides improved dispersion curves for the EPPS.

Conversions between magnetic and kinetic energy occur over a range of plasma scales in astrophysical and solar dynamos and reconnection in the solar corona and the laboratory. Canonical flux tubes reconcile all plasma regimes with concepts of twists, writhes, and linkages. We present measurements of canonical flux tubes, their helicity, and their helicity transport in a gyrating plasma kink. The helicity gauge is removed with general techniques valid even if only a limited section of the plasma is measured. Temporal asymmetries in the helicities confirm irreducible 3D fields in the kink.