Integrated Hardfacing of Stellite-6 Using Hybrid Manufacturing Process

Hybrid manufacturing systems provide a platform for integrated additive, subtractive and inspection methods on a single machine setup. The present work explores use of hybrid manufacturing for hardfacing of performance components for improving wear resistance. In this work, Stellite-6 was applied to a 410 stainless steel substrate using a hybrid manufacturing system incorporating multi-axis directed energy deposition and machining. Experimental testing was conducted to determine the effects of hybrid manufacturing parameters on internal porosity, surface porosity and microstructure in the cladded material, as well as on the roughness of the final machined surface. Correlation between porosity measurements made by x-ray tomography and surface inspection is presented and determination of ideal process parameters for hardfacing of components using hybrid manufacturing systems is briefly discussed. A deposition process is presented and implemented on a large industrial component. The component is inspected using dye-penetrant testing and metallographic techniques.Mechanical Engineerin

Serotonin and Coronary Artery Disease

To the Editor: Two articles1,2 and an editorial3 in the March 7 issue reported a possible role for serotonin in the pathogenesis of clinical coronary ischemia. Golino et al. noted that “it is still uncertain whether serotonin is important in modulating coronary-artery tone in humans.” 1 McFadden et al. reported that the role of serotonin “in human coronary artery disease remains largely speculative.”2 In the accompanying editorial, Hillis and Lange noted that the reported data “suggest that treatment with a serotonin antagonist may be beneficial in patients with [unstable angina].”3 In a previously published report4 we reviewed the case of a. © 1991, Massachusetts Medical Society. All rights reserved

Pipeline for Uncoilable or Failed Aneurysms: Results From a Multicenter Clinical Trial

Purpose: To evaluate the safety and effectiveness of the Pipeline Embolization Device (PED; ev3/Covidien, Irvine, Calif) in the treatment of complex intracranial aneurysms. Materials and Methods: The Pipeline for Uncoilable or Failed Aneurysms is a multicenter, prospective, interventional, single-arm trial of PED for the treatment of uncoilable or failed aneurysms of the internal carotid artery. Institutional review board approval of the HIPAA-compliant study protocol was obtained from each center. After providing informed consent, 108 patients with recently unruptured large and giant wide-necked aneurysms were enrolled in the study. The primary effectiveness endpoint was angiographic evaluation that demonstrated complete aneurysm occlusion and absence of major stenosis at 180 days. The primary safety endpoint was occurrence of major ipsilateral stroke or neurologic death at 180 days. Results: PED placement was technically successful in 107 of 108 patients (99.1%). Mean aneurysm size was 18.2 mm; 22 aneurysms (20.4%) were giant (>25 mm). Of the 106 aneurysms, 78 met the study's primary effectiveness endpoint (73.6%; 95% posterior probability interval: 64.4%81.0%). Six of the 107 patients in the safety cohort experienced a major ipsilateral stroke or neurologic death (5.6%; 95% posterior probability interval: 2.6%-11.7%). Conclusion: PED offers a reasonably safe and effective treatment of large or giant intracranial internal carotid artery aneurysms, demonstrated by high rates of complete aneurysm occlusion and low rates of adverse neurologic events; even in aneurysms failing previous alternative treatments.WoSScopu

Neuroophthalmological Outcomes Associated With Use of the Pipeline Embolization Device: Analysis of the PUFS Trial Results

Object Neuroophthalmological morbidity is commonly associated with large and giant cavernous and supraclinoid internal carotid artery (ICA) aneurysms. The authors sought to evaluate the neuroophthalmological outcomes after treatment of these aneurysms with the Pipeline Embolization Device (PED). Methods The Pipeline for Uncoilable or Failed Aneurysms (PUFS) trial was an international, multicenter prospective trial evaluating the safety and efficacy of the PED. All patients underwent complete neuroophthalmological examinations both before the PED procedure and at a 6-month follow-up. All examinations were performed for the purpose of this study and according to study criteria. Results In total, 108 patients were treated in the PUFS trial, 98 of whom had complete neuroophthalmological follow-up. Of the patients with complete follow-up, 39 (40%) presented with a neuroophthalmological baseline deficit that was presumed to be attributable to the aneurysm, and patients with these baseline deficits had significantly larger aneurysms. In 25 of these patients (64%), the baseline deficit showed at least some improvement 6 months after PED treatment, whereas in 1 patient (2.6%), the deficits only worsened. In 5 patients (5%), new deficits had developed at the 6-month follow-up, while in another 6 patients (6%), deficits that were not originally assumed to be related to the aneurysm had improved by that time. A history of diabetes was associated with failure of the baseline deficits to improve after the treatment. The aneurysm maximum diameter was significantly larger in patients with a new deficit or a worse baseline deficit at 6 months postprocedure. Conclusions Patients treated with the PED for large and giant ICA aneurysms had excellent neuroophthalmological outcomes 6 months after the procedure, with deficits improving in most of the patients, very few deficits worsening, and few new deficits developing

Long-Term Clinical and Angiographic Outcomes Following Pipeline Embolization Device Treatment of Complex Internal Carotid Artery Aneurysms: Five-Year Results of the Pipeline for Uncoilable or Failed Aneurysms Trial

BACKGROUND: Early and mid-term safety and efficacy of aneurysm treatment with the Pipeline Embolization Device (PED) has been well demonstrated in prior studies. OBJECTIVE: To present 5-yr follow-up for patients treated in the Pipeline for Uncoilable or Failed Aneurysms clinical trial. METHODS: In our prospective, multicenter trial, 109 complex internal carotid artery (ICA) aneurysms in 107 subjects were treated with the PED. Patients were followed per a standardized protocol at 180 d and 1, 3, and 5 yr. Aneurysm occlusion, in-stent stenosis, modified Rankin Scale scores, and complications were recorded. RESULTS: The primary endpoint of complete aneurysm occlusion at 180 d (73.6%) was previously reported. Aneurysm occlusion for those patients with angiographic follow-up progressively increased over time to 86.8% (79/91), 93.4% (71/76), and 95.2% (60/63) at 1, 3, and 5 yr, respectively. Six aneurysms (5.7%) were retreated. New serious device-related events at 1, 3, and 5 yr were noted in 1% (1/96), 3.5% (3/85), and 0% (0/81) of subjects. There were 4 (3.7%) reported deaths in our trial. Seventy-eight (96.3%) of 81 patients with 5-yr clinical follow-up had modified Rankin Scale scores ≤2. No delayed neurological deaths or hemorrhagic or ischemic cerebrovascular events were reported beyond 6 mo. No recanalization of a previously occluded aneurysm was observed. CONCLUSION: Our 5-yr findings demonstrate that PED is a safe and effective treatment for large and giant wide-necked aneurysms of the intracranial ICA, with high rates of complete occlusion and low rates of delayed adverse events

Linguistic Annotation in/for Corpus Linguistics

This article surveys linguistic annotation in corpora and corpus linguistics. We first define the concept of ‘corpus’ as a radial category and then, in Sect.2, discuss a variety of kinds of information for which corpora are annotated and that are exploited in contemporary corpus linguistics. Section3 then exemplifies many current formats of annotation with an eye to highlighting both the diversity of formats currently available and the emergence of XML annotation as, for now, the most widespread form of annotation. Section4 summarizes and concludes with desiderata for future developments.This article surveys linguistic annotation in corpora and corpus linguistics. We first define the concept of ‘corpus’ as a radial category and then, in Sect.2, discuss a variety of kinds of information for which corpora are annotated and that are exploited in contemporary corpus linguistics. Section3 then exemplifies many current formats of annotation with an eye to highlighting both the diversity of formats currently available and the emergence of XML annotation as, for now, the most widespread form of annotation. Section4 summarizes and concludes with desiderata for future developments