Raman study of CFC tiles extracted from the toroidal pump limiter of Tore Supra

International audienceThe structure of six tiles extracted from the erosion and deposition zones (thin and thick deposition) of the Tore Supra toroidal pump limiter (TPL) have been analysed in the framework of the DITS campaign using micro-Raman spectroscopy. This post-mortem analysis gives information on both carbon structure and D content. We have found that the carbon structure is most often similar to that of plasma-deposited hard amorphous carbon layers. The role of the surface temperature during the discharge in the D content is investigated: in all locations where the temperature does not reach more than 500°C the D content seems to be roughly uniform with D/D+C ≈ 20%

Early Endarterectomy Carries a Lower Procedural Risk Than Early Stenting in Patients With Symptomatic Stenosis of the Internal Carotid Artery: Results From 4 Randomized Controlled Trials.

Patients undergoing carotid endarterectomy (CEA) for symptomatic stenosis of the internal carotid artery benefit from early intervention. Heterogeneous data are available on the influence of timing of carotid artery stenting (CAS) on procedural risk. We investigated the association between timing of treatment (0-7 days and >7 days after the qualifying neurological event) and the 30-day risk of stroke or death after CAS or CEA in a pooled analysis of individual patient data from 4 randomized trials by the Carotid Stenosis Trialists' Collaboration. Analyses were done per protocol. To obtain combined estimates, logistic mixed models were applied. Among a total of 4138 patients, a minority received their allocated treatment within 7 days after symptom onset (14% CAS versus 11% CEA). Among patients treated within 1 week of symptoms, those treated by CAS had a higher risk of stroke or death compared with those treated with CEA: 8.3% versus 1.3%, risk ratio, 6.7; 95% confidence interval, 2.1 to 21.9 (adjusted for age at treatment, sex, and type of qualifying event). For interventions after 1 week, CAS was also more hazardous than CEA: 7.1% versus 3.6%, adjusted risk ratio, 2.0; 95% confidence interval, 1.5 to 2.7 (P value for interaction with time interval 0.06). In randomized trials comparing stenting with CEA for symptomatic carotid artery stenosis, CAS was associated with a substantially higher periprocedural risk during the first 7 days after the onset of symptoms. Early surgery is safer than stenting for preventing future stroke. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00190398; URL: http://www.controlled-trials.com. Unique identifier: ISRCTN57874028; URL: http://www.controlled-trials.com. Unique identifier: ISRCTN25337470; URL: http://www.clinicaltrials.gov. Unique identifier: NCT00004732

Correlated Microscopic Observations of Arterial Responses to Intravascular Stenting

Percutaneous catheter implantation of intravascular stent prostheses has emerged as a novel clinical adjunct to balloon angioplasty in the treatment of obstructive atherosclerotic vascular disease. We have examined the cellular and subcellular responses to stenting in the coronary arteries of the dog and pig (both normal and atherosclerotic), and in the iliac arteries and aorta of the atherosclerotic rabbit, using scanning electron, transmission electron, and light microscopies. Stenting in these models resulted in a thrombotic reaction ranging from mild to severe, depending on species and antithrombotic therapy. Subsequent organization of thrombotic material with hyperplasia of smooth muscle and inflammatory cells, luminal recovering with endothelial or pseudoendothelial cells, and atrophy of the tunica media led to incorporation of the prosthesis into the arterial wall. Endothelial or pseudoendothelial cells were observed adherent to the prosthesis as early as one day after placement, and regeneration of a confluent periluminal cell layer occurred within 2 to 4 weeks. Persistent ultrastructural abnormalities of the periluminal cell layer were seen as late as 2 years after stenting, but the intimal hyperplastic response appeared limited

Progress Report on Target Development

The present document is the D08 deliverable report of work package 1 (Target Development) from the MEGAPIE TEST project of the 5th European Framework Program. Deliverable D08 is the progress report on the activities performed within WP 1. The due date of this deliverable was the 5th month after the start of the EU project. This coincided with a technical status meeting of the MEGAPIE Initiative, that was held in March 2002 in Bologna (Italy). The content of the present document reflects the status of the MEGAPIE target development at that stage. It gives an overview of the Target Design, the related Design Support activities and the progress of the work done for the safety assessment and licensing of the target

Raman micro-spectroscopy as a tool to measure the absorption coefficient and the erosion rate of hydrogenated amorphous carbon films heat-treated under hydrogen bombardment

We present a fast and simple way to determine the erosion rate and absorption coefficient of hydrogenated amorphous carbon films exposed to a hydrogen atomic source based on ex-situ Raman micro-spectroscopy. Results are compared to ellipsometry measurement. The method is applied to films eroded at different temperatures. A maximum of the erosion rate is found at ~ 450 {\degree}C in agreement with previous results. This technique is suitable for future quantitative studies on the erosion of thin carbonaceous films, especially of interest for plasma wall interactions occurring in thermonuclear fusion devices

"Assessment of effectiveness and security in high pressure postdilatation of bioresorbable vascular scaffolds during percutaneous coronary intervention. Study in a contemporary, non-selected cohort of Spanish patients"

OBJECTIVES: To determine security and benefits of high pressure postdilatation (HPP) of bioresorbable vascular scaffolds (BVS) in percutaneous coronary intervention (PCI) of complex lesions whatever its indication is. BACKGROUND: Acute scaffold disruption has been proposed as the main limitation of BVS when they are overexpanded. However, clinical implications of this disarray are not yet clear and more evidence is needed. METHODS: A total of 25 BVS were deployed during PCI of 14 complex lesions after mandatory predilatation. In all cases HPP was performed with NC balloon in a 1:1 relation to the artery. After that, optical coherence tomography (OCT) analyses were performed. RESULTS: Mean and maximal postdilatation pressure were 17±3.80 and 20 atmospheres (atm) respectively. Postdilatation balloon/scaffold diameter ratio was 1.01. A total of 39,590 struts were analyzed. Mean, minimal and maximal scaffold diameter were respectively: 3.09±0.34mm, 2.88±0.31mm and 3.31±0.40mm. Mean eccentricity index was 0.13±0.05. ISA percentage was 1.42% with a total of 564 malapposed struts. 89 struts were identified as disrupted, which represents a percentage of disrupted struts of 0.22%. At 30days, none of our patients died, suffered from stroke, stent thrombosis or needed target lesion revascularization (TLR). CONCLUSIONS: NC balloon HPP of BVS at more than 17atm (up to 20atm) is safe during PCI and allows to achieve better angiographic and clinical results