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- Ederle, Joerg, et al.
(författare)
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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
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Ingår i: The Lancet. - 1474-547X. ; 375:9719, s. 985-997
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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.
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| 3. |
- Norek, M., et al.
(författare)
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Synthesis and decomposition mechanisms of ternary Mg2COH5 studied using in situ synchrotron X-ray diffraction
- 2011
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Ingår i: International Journal of Hydrogen Energy. - : Elsevier BV. - 1879-3487 .- 0360-3199. ; 36:17, s. 10760-10770
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Tidskriftsartikel (refereegranskat)abstract
- A ternary Mg2COH5 hydride was synthesized using a novel method that relies on a relatively short mechanical milling time (1 h) of a 2:1 MgH2-Co powder mixture followed by sintering at a sufficiently high hydrogen pressure (>85 bar) and heating from RT to 500 degrees C. The ternary hydride forms in less than 2.5 h (including the milling time) with a yield of similar to 90% at similar to 300 degrees C. The mechanisms of formation and decomposition of ternary Mg2COH5 were studied in detail using an in situ synchrotron radiation powder X-ray diffraction (SR-PXD). The obtained experimental results are supported by morphological and microstructural investigations performed using SEM and high-resolution STEM. Additionally, thermal effects occurring during the desorption reaction were studied using DSC. The morphology of as-prepared ternary Mg2COH5 is characterized by the presence of porous particles with various shapes and sizes, which, in fact, are a type of nanocomposite consisting mainly of nanocrystallites with a size of similar to 5 nm. Mg2COH5 decomposes at approximately 300 degrees C to elemental Mg and Co. Additionally, at approximately 400 degrees C, MgCo is formed as precipitates inserted into the Mg Co matrix. During the rehydrogenation of the decomposed residues, prior to the formation of Mg2COH5, MgH2 appears, which confirms its key role in the synthesis of the ternary Mg2COH5. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
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| 4. |
- Polanski, M., et al.
(författare)
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Mg2NiH4 synthesis and decomposition reactions
- 2013
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Ingår i: International Journal of Hydrogen Energy. - : Elsevier BV. - 1879-3487 .- 0360-3199. ; 38:10, s. 4003-4010
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Tidskriftsartikel (refereegranskat)abstract
- A ternary Mg2NiH4 hydride was synthesized using method that relies on a relatively short mechanical milling time (one hour) of a 2:1 MgH2-Ni powder mixture followed by sintering at a sufficiently high hydrogen pressure (>85 bar) and temperature (>400 degrees C). The ternary hydride forms in less than 2.5 h (including the milling time) with a yield of similar to 90% as a mixture of two polymorphic forms. The mechanisms of formation and decomposition of ternary Mg2NiH4 under different hydrogen pressures were studied in detail using an in situ synchrotron radiation powder X-ray diffraction (SR-PXD) and high pressure DSC. The obtained experimental results are supported by morphological and microstructural investigations performed using SEM and high resolution STEM. Additionally, effects occurring during the desorption reaction were studied using DSC coupled with mass spectrometry. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
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| 5. |
- Polanski, M., et al.
(författare)
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Synthesis and decomposition mechanisms of Mg2FeH6 studied by in-situ synchrotron X-ray diffraction and high-pressure DSC
- 2010
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Ingår i: International Journal of Hydrogen Energy. - : Elsevier BV. - 1879-3487 .- 0360-3199. ; 35:8, s. 3578-3582
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Tidskriftsartikel (refereegranskat)abstract
- Synthesis and decomposition mechanisms of ternary Mg2FeH6 were investigated using in-situ synchrotron radiation powder X-ray diffraction (SR-PXD) and high-pressure differential scanning calorimetry (HP-DSC). Two routes for synthesis of Mg2FeH6 were studied. The first utilizes a ball-milled homogeneous MgH2-Fe powder mixture and the second uses a mixture of Fe and Mg formed by decomposition of the ternary hydride, Mg2FeH6. In both cases the reaction mixture was sintered in a temperature range from RT to 500 degrees C under a hydrogen pressure of 100-120 bar. The reaction mechanisms were established using in-situ SR-PXD. The formation of Mg2FeH6 consists of two steps with MgH2 as an intermediate compound, and the presence of magnesium was not observed. In contrast, the decomposition of Mg2FeH6 was found to be a single-step reaction. Additionally, both reactions were investigated using HP-DSC under similar conditions as in the SR-PXD experiments in order to estimate reaction enthalpies and temperatures. Mg2FeH6 was found to form from MgH2 and Fe under hydrogen pressure regardless of whether the MgH2 was introduced in the mixture or formed prior to creation of the ternary hydride. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.
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