| 11. |
- Apponi, A., et al.
(författare)
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Heisenberg's uncertainty principle in the PTOLEMY project : A theory update
- 2022
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Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 106:5
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Tidskriftsartikel (refereegranskat)abstract
- We discuss the consequences of the quantum uncertainty on the spectrum of the electron emitted by the beta-processes of a tritium atom bound to a graphene sheet. We analyze quantitatively the issue recently raised by Cheipesh, Cheianov, and Boyarsky [Phys. Rev. D 104, 116004 (2021)], and discuss the relevant timescales and the degrees of freedom that can contribute to the intrinsic spread in the electron energy. We perform careful calculations of the potential between tritium and graphene with different coverages and geometries. With this at hand, we propose possible avenues to mitigate the effect of the quantum uncertainty.
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| 12. |
- Apponi, A., et al.
(författare)
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Implementation and optimization of the PTOLEMY transverse drift electromagnetic filter
- 2022
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Ingår i: Journal of Instrumentation. - : IOP Publishing Ltd. - 1748-0221. ; 17:5
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Tidskriftsartikel (refereegranskat)abstract
- The PTOLEMY transverse drift filter is a new concept to enable precision analysis of the energy spectrum of electrons near the tritium beta-decay endpoint. This paper details the implementation and optimization methods for successful operation of the filter for electrons with a known pitch angle. We present the first demonstrator that produces the required magnetic field properties with an iron return-flux magnet. Two methods for the setting of filter electrode voltages are detailed. The challenges of low-energy electron transport in cases of low field are discussed, such as the growth of the cyclotron radius with decreasing magnetic field, which puts a ceiling on filter performance relative to fixed filter dimensions. Additionally, low pitch angle trajectories are dominated by motion parallel to the magnetic field lines and introduce non-adiabatic conditions and curvature drift. To minimize these effects and maximize electron acceptance into the filter, we present a three-potential-well design to simultaneously drain the parallel and transverse kinetic energies throughout the length of the filter. These optimizations are shown, in simulation, to achieve low-energy electron transport from a 1 T iron core (or 3 T superconducting) starting field with initial kinetic energy of 18.6 keV drained to < 10 eV (< 1 eV) in about 80 cm. This result for low field operation paves the way for the first demonstrator of the PTOLEMY spectrometer for measurement of electrons near the tritium endpoint to be constructed at the Gran Sasso National Laboratory (LNGS) in Italy.
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| 15. |
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| 16. |
- Biancari, F, et al.
(författare)
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Late Myocardial Infarction and Repeat Revascularization after Coronary Artery Bypass Grafting in Patients with Prior Percutaneous Coronary Intervention
- 2022
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Ingår i: Journal of clinical medicine. - : MDPI AG. - 2077-0383. ; 11:19
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The aim of the present study was to evaluate the risk of late mortality and major adverse cardiovascular and cerebral events after coronary artery bypass grafting (CABG) in patients with prior percutaneous coronary intervention (PCI). Methods: A total of 2948 patients undergoing isolated CABGs were included in a prospective multicenter registry. Outcomes were adjusted for multiple covariates in logistic regression, Cox proportional hazards analysis and competing risk analysis. Results: In all, 2619 patients fulfilled the inclusion criteria of this analysis. Of them, 2199 (79.1%) had no history of PCI and 420 (20.9%) had a prior PCI. An adjusted analysis showed that a single prior PCI and multiple prior PCIs did not increase the risk of 30-day and 5-year mortality. Patients with multiple prior PCIs had a significantly higher risk of 5-year myocardial infarction (SHR 2.566, 95%CI 1.379–4.312) and repeat revascularization (SHR 1.774, 95%CI 1.140–2.763). Similarly, 30-day and 5-year mortality were not significantly increased in patients with prior PCI treatment of single or multiple vessels. Patients with multiple vessels treated with PCI had a significantly higher risk of 5-year myocardial infarction (SHR 2.640, 95%CI 1.497–4.658), repeat revascularization (SHR 1.648, 95%CI 1.029–2.638) and stroke (SHR 2.215, 95%CI 1.056–4.646) at 5-year. The risk for repeat revascularization was also increased with a prior single vessel PCI, but not for other outcomes. Conclusions: Among patients undergoing CABGs, multiple prior PCIs seem to increase the risk of late myocardial infarction and the need for repeat revascularization, but not the risk of mortality.
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| 17. |
- Biancari, F, et al.
(författare)
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Preoperative risk stratification of deep sternal wound infection after coronary surgery
- 2020
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Ingår i: Infection control and hospital epidemiology. - : Cambridge University Press (CUP). - 1559-6834 .- 0899-823X. ; 41:4, s. 444-451
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Tidskriftsartikel (refereegranskat)abstract
- Objective:To develop a risk score for deep sternal wound infection (DSWI) after isolated coronary artery bypass grafting (CABG).Design:Multicenter, prospective study.Setting:Tertiary-care referral hospitals.Participants:The study included 7,352 patients from the European multicenter coronary artery bypass grafting (E-CABG) registry.Intervention:Isolated CABG.Methods:An additive risk score (the E-CABG DSWI score) was estimated from the derivation data set (66.7% of patients), and its performance was assessed in the validation data set (33.3% of patients).Results:DSWI occurred in 181 (2.5%) patients and increased 1-year mortality (adjusted hazard ratio, 4.275; 95% confidence interval [CI], 2.804–6.517). Female gender (odds ratio [OR], 1.804; 95% CI, 1.161–2.802), body mass index ≥30 kg/m2(OR, 1.729; 95% CI, 1.166–2.562), glomerular filtration rate <45 mL/min/1.73 m2(OR, 2.410; 95% CI, 1.413–4.111), diabetes (OR, 1.741; 95% CI, 1.178–2.573), pulmonary disease (OR, 1.935; 95% CI, 1.178–3.180), atrial fibrillation (OR, 1.854; 95% CI, 1.096–3.138), critical preoperative state (OR, 2.196; 95% CI, 1.209–3.891), and bilateral internal mammary artery grafting (OR, 2.088; 95% CI, 1.422–3.066) were predictors of DSWI (derivation data set). An additive risk score was calculated by assigning 1 point to each of these independent risk factors for DSWI. In the validation data set, the rate of DSWI increased along with the E-CABG DSWI scores (score of 0, 1.0%; score of 1, 1.8%; score of 2, 2.2%; score of 3, 6.9%; score ≥4: 12.1%;P< .0001). Net reclassification improvement, integrated discrimination improvement, and decision curve analysis showed that the E-CABG DSWI score performed better than other risk scores.Conclusions:DSWI is associated with poor outcome after CABG, and its risk can be stratified using the E-CABG DSWI score.Trial registration:clinicaltrials.gov identifier: NCT02319083
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