| 1. |
|
|
| 2. |
- Ederle, Joerg, et al.
(författare)
-
Carotid artery stenting compared with endarterectomy in patients with symptomatic carotid stenosis (International Carotid Stenting Study): an interim analysis of a randomised controlled trial
- 2010
-
Ingår i: The Lancet. - 1474-547X. ; 375:9719, s. 985-997
-
Tidskriftsartikel (refereegranskat)abstract
- Background Stents are an alternative treatment to carotid endarterectomy for symptomatic carotid stenosis, but previous trials have not established equivalent safety and efficacy. We compared the safety of carotid artery stenting with that of carotid endarterectomy. Methods The International Carotid Stenting Study (ICSS) is a multicentre, international, randomised controlled trial with blinded adjudication of outcomes. Patients with recently symptomatic carotid artery stenosis were randomly assigned in a 1:1 ratio to receive carotid artery stenting or carotid endarterectomy. Randomisation was by telephone call or fax to a central computerised service and was stratified by centre with minimisation for sex, age, contralateral occlusion, and side of the randomised artery. Patients and investigators were not masked to treatment assignment. Patients were followed up by independent clinicians not directly involved in delivering the randomised treatment. The primary outcome measure of the trial is the 3-year rate of fatal or disabling stroke in any territory, which has not been analysed yet. The main outcome measure for the interim safety analysis was the 120-day rate of stroke, death, or procedural myocardial infarction. Analysis was by intention to treat (ITT). This study is registered, number ISRCTN25337470. Findings The trial enrolled 1713 patients (stenting group, n=855; endarterectomy group, n=858). Two patients in the stenting group and one in the endarterectomy group withdrew immediately after randomisation, and were not included in the ITT analysis. Between randomisation and 120 days, there were 34 (Kaplan-Meier estimate 4.0%) events of disabling stroke or death in the stenting group compared with 27 (3.2%) events in the endarterectomy group (hazard ratio [HR] 1.28, 95% CI 0.77-2.11). The incidence of stroke, death, or procedural myocardial infarction was 8.5% in the stenting group compared with 5.2% in the endarterectomy group (72 vs 44 events; HR 1.69, 1.16-2.45, p=0.006), Risks of any stroke (65 vs 35 events; HR 1.92, 1.27-2.89) and all-cause death (19 vs seven events; HR 2.76, 1.16-6.56) were higher in the stenting group than in the endarterectomy group. Three procedural myocardial infarctions were recorded in the stenting group, all of which were fatal, compared with four, all non-fatal, in the endarterectomy group. There was one event of cranial nerve palsy in the stenting group compared with 45 in the endarterectomy group. There were also fewer haematomas of any severity in the stenting group than in the endarterectomy group (31 vs 50 events; p=0.0197). Interpretation Completion of long-term follow-up is needed to establish the efficacy of carotid artery stenting compared with endarterectomy. In the meantime, carotid endarterectomy should remain the treatment of choice for patients suitable for surgery.
|
|
| 3. |
- Zouganelis, I., et al.
(författare)
-
The Solar Orbiter Science Activity Plan : Translating solar and heliospheric physics questions into action
- 2020
-
Ingår i: Astronomy and Astrophysics. - : EDP SCIENCES S A. - 0004-6361 .- 1432-0746. ; 642
-
Tidskriftsartikel (refereegranskat)abstract
- Solar Orbiter is the first space mission observing the solar plasma both in situ and remotely, from a close distance, in and out of the ecliptic. The ultimate goal is to understand how the Sun produces and controls the heliosphere, filling the Solar System and driving the planetary environments. With six remote-sensing and four in-situ instrument suites, the coordination and planning of the operations are essential to address the following four top-level science questions: (1) What drives the solar wind and where does the coronal magnetic field originate?; (2) How do solar transients drive heliospheric variability?; (3) How do solar eruptions produce energetic particle radiation that fills the heliosphere?; (4) How does the solar dynamo work and drive connections between the Sun and the heliosphere? Maximising the mission's science return requires considering the characteristics of each orbit, including the relative position of the spacecraft to Earth (affecting downlink rates), trajectory events (such as gravitational assist manoeuvres), and the phase of the solar activity cycle. Furthermore, since each orbit's science telemetry will be downloaded over the course of the following orbit, science operations must be planned at mission level, rather than at the level of individual orbits. It is important to explore the way in which those science questions are translated into an actual plan of observations that fits into the mission, thus ensuring that no opportunities are missed. First, the overarching goals are broken down into specific, answerable questions along with the required observations and the so-called Science Activity Plan (SAP) is developed to achieve this. The SAP groups objectives that require similar observations into Solar Orbiter Observing Plans, resulting in a strategic, top-level view of the optimal opportunities for science observations during the mission lifetime. This allows for all four mission goals to be addressed. In this paper, we introduce Solar Orbiter's SAP through a series of examples and the strategy being followed.
|
|
| 4. |
- Perrone, D., et al.
(författare)
-
Evolution of coronal hole solar wind in the inner heliosphere : Combined observations by Solar Orbiter and Parker Solar Probe
- 2022
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 668
-
Tidskriftsartikel (refereegranskat)abstract
- We study the radial evolution, from 0.1 AU to the Earth, of a homogeneous recurrent fast wind, coming from the same source on the Sun, by means of new measurements by both Solar Orbiter and Parker Solar Probe. With respect to previous radial studies, we extend, for the first time, the analysis of a recurrent fast stream at distances never reached prior to the Parker Solar Probe mission. Confirming previous findings, the observations show: (i) a decrease in the radial trend of the proton density that is slower than the one expected for a radially expanding plasma, due to the possible presence of a secondary beam in the velocity distribution function; (ii) a deviation for the magnetic field from the Parker prediction, supported by the strong Alfvenicity of the stream at all distances; and (iii) a slower decrease in the proton temperature with respect to the adiabatic prediction, suggesting the local presence of external heating mechanisms. Focusing on the radial evolution of the turbulence, from the inertial to the kinetic range along the turbulent cascade, we find that the slopes, in both frequency ranges, strongly depend on the different turbulence observed by the two spacecraft, namely a mostly parallel turbulence in the Parker Solar Probe data and a mostly perpendicular turbulence in the Solar Orbiter intervals. Moreover, we observe a decrease in the level of intermittency for the magnetic field during the expansion of the stream. Furthermore, we perform, for the first time, a statistical analysis of coherent structures around proton scales at 0.1 AU and we study how some of their statistical properties change from the Sun to the Earth. As expected, we find a higher occurrence of events in the Parker Solar Probe measurements than in the Solar Orbiter data, considering the ratio between the intervals length and the proton characteristic scales at the two radial distances. Finally, we complement this statistical analysis with two case studies of current sheets and vortex-like structures detected at the two radial distances, and we find that structures that belong to the same family have similar characteristics at different radial distances. This work provides an insight into the radial evolution of the turbulent character of solar wind plasma coming from coronal holes.
|
|
| 5. |
|
|
| 6. |
- Patnaik, Sobhan, et al.
(författare)
-
Crystallographic characterization of U 2 CrN 3 : A neutron diffraction and transmission electron microscopy approach
- 2023
-
Ingår i: Nuclear Materials and Energy. - : Elsevier BV. - 2352-1791. ; 35
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, neutron diffraction and transmission electron microscopy (TEM) have been implemented to study the crystallographic structure of the ternary phase U2CrN3 from pellet to nano scale respectively. Recently microstructural evaluation of this ternary phase has been performed for the first time in pellet condition, overcoming the Cr evaporation issue during the conventional sintering process. In this work for the first time, the crystallographic structure of the ordered ternary U2CrN3 phase, stabilized in pellet condition, has been obtained by implementing neutron diffraction. For this study, pellets of the composite material UN with 20 vol% CrN were fabricated by powder metallurgy by mixing UN and CrN powders followed by Spark Plasma Sintering (SPS). TEM was used to investigate the nanoscale structure with a thin lamella of the order of 100–140 nm produced by focused ion beam (FIB). The neutron data revealed the phase composition of the pellet to be primarily 54(8) wt.% U2CrN3, in good agreement with the stoichiometry of starting reagents (UN and CrN powder) and metallographic analysis. Neutron data analysis confirms that all the crystallographic sites in U2CrN3 phase are fully occupied reinforcing the fully stoichiometric composition of this phase, however, the position of the N at the 4i site was found to be closer to the Cr than previously thought. TEM and selected area electron diffraction rendered nano-level information and revealed the presence of nano domains along grain boundaries of UN and U2CrN3, indicating a formation mechanism of the ternary phase, where the phase likely nucleates as nano domains in UN grains from migration of Cr.
|
|
| 7. |
- Verscharen, Daniel, et al.
(författare)
-
The angular-momentum flux in the solar wind observed during Solar Orbiter's first orbit
- 2021
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 656
-
Tidskriftsartikel (refereegranskat)abstract
- Aims. We present the first measurements of the angular-momentum flux in the solar wind recorded by the Solar Orbiter spacecraft. Our aim is to validate these measurements to support future studies of the Sun's angular-momentum loss. Methods. We combined 60-min averages of the proton bulk moments and the magnetic field measured by the Solar Wind Analyser and the magnetometer onboard Solar Orbiter. We calculated the angular-momentum flux per solid-angle element using data from the first orbit of the mission's cruise phase in 2020. We separated the contributions from protons and from magnetic stresses to the total angular-momentum flux.Results. The angular-momentum flux varies significantly over time. The particle contribution typically dominates over the magnetic-field contribution during our measurement interval. The total angular-momentum flux shows the largest variation and is typically anti-correlated with the radial solar-wind speed. We identify a compression region, potentially associated with a co-rotating interaction region or a coronal mass ejection, which leads to a significant localised increase in the angular-momentum flux, albeit without a significant increase in the angular momentum per unit mass. We repeated our analysis using the density estimate from the Radio and Plasma Waves instrument. Using this independent method, we find a decrease in the peaks of positive angular-momentum flux, but otherwise, our results remain consistent.Conclusions. Our results largely agree with previous measurements of the solar wind's angular-momentum flux in terms of amplitude, variability, and dependence on radial solar-wind bulk speed. Our analysis highlights the potential for more detailed future studies of the solar wind's angular momentum and its other large-scale properties with data from Solar Orbiter. We emphasise the need for studying the radial evolution and latitudinal dependence of the angular-momentum flux in combination with data from Parker Solar Probe and other assets at heliocentric distances of 1 au and beyond.
|
|
