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We propose a conceptual framework for describing and documenting sound installations from a visitor’s point of view. In the form of a taxonomy, the framework includes four complementary perspectives: sound sources, sound design approaches, visiting modalities and visual aspects. Its elaboration was informed by a review of contemporary sound installations in Quebec as well as a literature review on conceptual and theoretical frameworks on sound art and sound installations. Compared with existing frameworks, the taxonomy is useful for describing and comparing sound installations across meaningful perspectives from a visitor’s stance. To illustrate the potential benefits of the taxonomy and the diversity of installations it can portray, we provide a comparative analysis of four contemporary sound installations from different perspectives. We conclude with the use of this taxonomy for documentation purposes.

Background: The “1-3-6-12-day rule” for starting direct oral anticoagulants (DOACs) in patients with nonvalvular atrial fibrillation after acute ischemic stroke or transient ischemic attack recommends timings that may be later than used in clinical practice. We investigated more practical optimal timing of DOAC initiation according to stroke severity. Methods: The combined data of prospective registries in Japan, Stroke Acute Management with Urgent Risk-factor Assessment and Improvement-nonvalvular atrial fibrillation (September 2011 to March 2014) and RELAXED (February 2014 to April 2016) were used. Patients were divided into transient ischemic attack and 3 stroke subgroups by the National Institutes of Health Stroke Scale score: mild (0–7), moderate (8–15), and severe (≥16). The early treatment group was defined as patients starting DOACs earlier than the median initiation day in each subgroup. Outcomes included a composite of recurrent stroke or systemic embolism, ischemic stroke, and severe bleeding within 90 days. Six European prospective registries were used for validation. Results: In the 1797 derivation cohort patients, DOACs were started at median 2 days after transient ischemic attack and 3, 4, and 5 days after mild, moderate, and severe strokes, respectively. Stroke or systemic embolism was less common in Early Group (n=785)—initiating DOACS within 1, 2, 3, and 4 days, respectively—than Late Group (n=1012) (1.9% versus 3.9%; adjusted hazard ratio, 0.50 [95% CI, 0.27–0.89]), as was ischemic stroke (1.7% versus 3.2%, 0.54 [0.27–0.999]). Major bleeding was similarly common in the 2 groups (0.8% versus 1.0%). On validation, both ischemic stroke (2.4% versus 2.2%) and intracranial hemorrhage (0.2% versus 0.6%) were similarly common in Early (n=547) and Late (n=1483) Groups defined using derivation data. Conclusions: In Japanese and European populations, early DOAC initiation within 1, 2, 3, or 4 days according to stroke severity seemed to be feasible to decrease the risk of recurrent stroke or systemic embolism and no increase in major bleeding. These findings support ongoing randomized trials to better establish the optimal timing of DOAC initiation.

Continuing a trend of publications investigating sound art within a specific geographical context, this paper proposes an original view of the sound installation practice in Québec. This study is part of a research project aiming at building new theoretical and practical tools for the documentation of such artworks. In this paper we present the outcomes of the first phase and its connection with the bigger picture of the project, which is the questioning of the relevance of spatial audio recordings with six degrees of freedom (6DoF) for mediating the capture of knowledge relating to the sensory experience of a work. During the first phase, we developed a conceptual descriptive framework based on a mixed-methods approach, top-down and bottom-up, consisting in a systematic review of literature paralleled with a categorization of contemporary sound art production in Québec based on publicly available documentation. This process led to a formal and quantitative depiction of the Québec scene, which aims to guide both the selection of case studies for the next phases but also to be part of the conceptual tools for investigating the sensory experience of these works. This quantitative depiction of the scene will thus foster a qualitative investigation of the sensory experience of sound art installations and the knowledge that may be lost in standard written documentation practice with an original methodological framework.

Background: In patients with atrial fibrillation who suffered an ischemic stroke while on treatment with nonvitamin K antagonist oral anticoagulants, rates and determinants of recurrent ischemic events and major bleedings remain uncertain. Methods: This prospective multicenter observational study aimed to estimate the rates of ischemic and bleeding events and their determinants in the follow-up of consecutive patients with atrial fibrillation who suffered an acute cerebrovascular ischemic event while on nonvitamin K antagonist oral anticoagulant treatment. Afterwards, we compared the estimated risks of ischemic and bleeding events between the patients in whom anticoagulant therapy was changed to those who continued the original treatment. Results: After a mean follow-up time of 15.0±10.9 months, 192 out of 1240 patients (15.5%) had 207 ischemic or bleeding events corresponding to an annual rate of 13.4%. Among the events, 111 were ischemic strokes, 15 systemic embolisms, 24 intracranial bleedings, and 57 major extracranial bleedings. Predictive factors of recurrent ischemic events (strokes and systemic embolisms) included CHA 2 DS 2 -VASc score after the index event (odds ratio [OR], 1.2 [95% CI, 1.0–1.3] for each point increase; P =0.05) and hypertension (OR, 2.3 [95% CI, 1.0–5.1]; P =0.04). Predictive factors of bleeding events (intracranial and major extracranial bleedings) included age (OR, 1.1 [95% CI, 1.0–1.2] for each year increase; P =0.002), history of major bleeding (OR, 6.9 [95% CI, 3.4–14.2]; P =0.0001) and the concomitant administration of an antiplatelet agent (OR, 2.8 [95% CI, 1.4–5.5]; P =0.003). Rates of ischemic and bleeding events were no different in patients who changed or not changed the original nonvitamin K antagonist oral anticoagulants treatment (OR, 1.2 [95% CI, 0.8–1.7]). Conclusions: Patients suffering a stroke despite being on nonvitamin K antagonist oral anticoagulant therapy are at high risk of recurrent ischemic stroke and bleeding. In these patients, further research is needed to improve secondary prevention by investigating the mechanisms of recurrent ischemic stroke and bleeding.

Introduction The aim of this study in patients with acute posterior ischaemic stroke (PS) and atrial fibrillation (AF) was to evaluate (1) the risks of recurrent ischaemic event and severe bleeding and (2) these risks in relation with oral anticoagulant therapy (OAT) and its timing. Materials and Methods Patients with PS were prospectively included; the outcome events of these patients were compared with those of patients with anterior stroke (AS) which were taken from previous registries. The primary outcome was the composite of stroke recurrence, transient ischaemic attack, symptomatic systemic embolism, symptomatic cerebral bleeding and major extracranial bleeding occurring within 90 days from acute stroke. Results A total of 2470 patients were available for the analysis: 473 (19.1%) with PS and 1997 (80.9%) with AS. Over 90 days, 213 (8.6%) primary outcome events were recorded: 175 (8.7%) in patients with AS and 38 (8.0%) in those with PS. In patients who initiated OAT within 2 days, the primary outcome occurred in 5 out of 95 patients (5.3%) with PS compared to 21 out of 373 patients (4.3%) with AS (OR 1.07; 95% CI 0.39–2.94). In patients who initiated OAT between days 3 and 7, the primary outcome occurred in 3 out of 103 patients (2.9%) with PS compared to 26 out of 490 patients (5.3%) with AS (OR 0.54; 95% CI 0.16–1.80). Discussion our findings suggest that, when deciding the time to initiate oral anticoagulation, the location of stroke, either anterior or posterior, does not predict the risk of outcome events. Conclusions Patients with PS or AS and AF appear to have similar risks of ischaemic or haemorrhagic events at 90 days with no difference concerning the timing of initiation of OAT.

Background and Purpose— Despite treatment with oral anticoagulants, patients with nonvalvular atrial fibrillation (AF) may experience ischemic cerebrovascular events. The aims of this case-control study in patients with AF were to identify the pathogenesis of and the risk factors for cerebrovascular ischemic events occurring during non–vitamin K antagonist oral anticoagulants (NOACs) therapy for stroke prevention. Methods— Cases were consecutive patients with AF who had acute cerebrovascular ischemic events during NOAC treatment. Controls were consecutive patients with AF who did not have cerebrovascular events during NOACs treatment. Results— Overall, 713 cases (641 ischemic strokes and 72 transient ischemic attacks; median age, 80.0 years; interquartile range, 12; median National Institutes of Health Stroke Scale on admission, 6.0; interquartile range, 10) and 700 controls (median age, 72.0 years; interquartile range, 8) were included in the study. Recurrent stroke was classified as cardioembolic in 455 cases (63.9%) according to the A-S-C-O-D (A, atherosclerosis; S, small vessel disease; C, cardiac pathology; O, other causes; D, dissection) classification. On multivariable analysis, off-label low dose of NOACs (odds ratio [OR], 3.18; 95% CI, 1.95–5.85), atrial enlargement (OR, 6.64; 95% CI, 4.63–9.52), hyperlipidemia (OR, 2.40; 95% CI, 1.83–3.16), and CHA 2 DS 2 -VASc score (OR, 1.72 for each point increase; 95% CI, 1.58–1.88) were associated with ischemic events. Among the CHA 2 DS 2 -VASc components, age was older and presence of diabetes mellitus, congestive heart failure, and history of stroke or transient ischemic attack more common in patients who had acute cerebrovascular ischemic events. Paroxysmal AF was inversely associated with ischemic events (OR, 0.45; 95% CI, 0.33–0.61). Conclusions— In patients with AF treated with NOACs who had a cerebrovascular event, mostly but not exclusively of cardioembolic pathogenesis, off-label low dose, atrial enlargement, hyperlipidemia, and high CHA 2 DS 2 -VASc score were associated with increased risk of cerebrovascular events.

Background and Purpose— Bridging therapy with low-molecular-weight heparin reportedly leads to a worse outcome for acute cardioembolic stroke patients because of a higher incidence of intracerebral bleeding. However, this practice is common in clinical settings. This observational study aimed to compare (1) the clinical profiles of patients receiving and not receiving bridging therapy, (2) overall group outcomes, and (3) outcomes according to the type of anticoagulant prescribed. Methods— We analyzed data of patients from the prospective RAF and RAF-NOACs studies. The primary outcome was defined as the composite of ischemic stroke, transient ischemic attack, systemic embolism, symptomatic cerebral bleeding, and major extracerebral bleeding observed at 90 days after the acute stroke. Results— Of 1810 patients who initiated oral anticoagulant therapy, 371 (20%) underwent bridging therapy with full-dose low-molecular-weight heparin. Older age and the presence of leukoaraiosis were inversely correlated with the use of bridging therapy. Forty-two bridged patients (11.3%) reached the combined outcome versus 72 (5.0%) of the nonbridged patients ( P =0.0001). At multivariable analysis, bridging therapy was associated with the composite end point (odds ratio, 2.3; 95% CI, 1.4–3.7; P P =0.005) and hemorrhagic (odds ratio, 2.4; 95% CI, 1.2–4.9; P =0.01) end points separately. Conclusions— Our findings suggest that patients receiving low-molecular-weight heparin have a higher risk of early ischemic recurrence and hemorrhagic transformation compared with nonbridged patients.

INTRODUCTION: The postmortem examination still represents the reference standard for detecting the pathological nature of chronic neurodegenerative diseases (NDD). This approach displays intrinsic conceptual limitations since NDD represent a dynamic spectrum of partially overlapping phenotypes, shared pathomechanistic alterations that often give rise to mixed pathologies. AREAS COVERED: We scrutinized the international clinical diagnostic criteria of NDD and the literature to provide a roadmap toward a biomarker-based classification of the NDD spectrum. A few pathophysiological biomarkers have been established for NDD. These are time-consuming, invasive, and not suitable for preclinical detection. Candidate screening biomarkers are gaining momentum. Blood neurofilament light-chain represents a robust first-line tool to detect neurodegeneration tout court and serum progranulin helps detect genetic frontotemporal dementia. Ultrasensitive assays and retinal scans may identify Aβ pathology early, in blood and the eye, respectively. Ultrasound also represents a minimally invasive option to investigate the substantia nigra. Protein misfolding amplification assays may accurately detect α-synuclein in biofluids. EXPERT OPINION: Data-driven strategies using quantitative rather than categorical variables may be more reliable for quantification of contributions from pathophysiological mechanisms and their spatial-temporal evolution. A systems biology approach is suitable to untangle the dynamics triggering loss of proteostasis, driving neurodegeneration and clinical evolution.

Leukoaraiosis is one of the main contributors to mild cognitive impairment due to vascular damage (vascular MCI, VMCI), whose pathophysiology has not been fully elucidated yet. We aimed to shed light on such issue using functional MRI (fMRI). Sixteen patients with VMCI were enrolled and compared with twenty-five patients with MCI but without significant vascular damage (non-vascular MCI, NVMCI) and with fifteen healthy controls (HC). They all underwent fMRI with incidental verbal learning paradigm, using a 3T scanner. Differently from cases with NVMCI (versus HC), VMCI patients presented a higher BOLD activation in the right parieto-occipital cortex and a lower activation in the left superior and middle frontal gyri, anterior cingulum and in left fronto-opercular area when compared to HC. Cortical activation evaluated by fMRI may reflect specific patterns of damage and attempt of compensation in patients with MCI and different severity of leukoaraiosis.

Background: Leukoaraiosis (LA) is a common radiological finding in elderly, frequently associated with several clinical disorders, including unexplained dizziness. The pathogenesis of LA is multifactorial, with a dysfunction of cerebral microcirculation resulting in chronic hypoperfusion and tissue loss, with oxidative stress involved in this cascade. Objective: The aim of this study was to analyse some oxidative stress biomarkers in a cohort of LA patients. Method: Fifty-five consecutive patients (33 males, median age 75 years) with LA were recruited. In a subgroup of 33 patients with LA and unexplained dizziness, we have then performed an open study to evaluate if 60-day supplementation with a polyphenol compound may modify these biomarkers and influence quality of life, analysed with the Dizziness Handicap Inventory (DHI) scale. Results: At baseline, blood oxidative stress parameters values were outside normal ranges and compared to matched healthy controls. After the two months supplementation, we observed a significant decrement of advanced oxidation protein products values and a significant improvement of DHI. Conclusion: Oxidative stress biomarkers may be useful to detect redox imbalance in LA and to provide non-invasive tools to monitor disease status and response to therapy.

Spontaneous dissection of cervical arteries (sCAD) is a major cause of ischemic stroke in young patients, with an incidence varying from 1.7 to 3/100,000/year for extracranial internal carotid artery (ICAD) and 1 to 1.9/100,000/year for extracranial vertebral artery (VAD). Reliable epidemiological data on stroke incidence related to sCAD are scarce in Italy. This study aims to evaluate the incidence, clinical features, and outcome of cerebrovascular events related to sCAD and spontaneous intracranial arteries dissections (sIAD) in the city of Pisa (Italy). We retrospectively analyzed consecutive patients admitted between December 1997 and June 2015 with a diagnosis of stroke, TIA, or Bernard-Horner syndrome due to acute cervical or intracranial artery dissection. Considering that our hospital collects presumptively all patients hospitalized with sCAD coming from the referral geographical area, data may provide a good approximation to real incidence of sCAD in our population. Clinical and radiological features, acute treatment and outcome were collected. Seventy-seven cases were included (mean age 48.1±10.4 years, range 23-77,72.7% males), 66 residents in the district of Pisa. Crude incidence rate of cerebrovascular events due to intra or extracranial dissection was 1.88/100,000/year. The incidence of ICAD was 0.80/100,000/year and 0.43/100,000/year for VAD. Stroke occurred in 76.6% of patients. VAD was more prone to cause ischemic stroke and present with cervical pain or focal signs (p

Background and Purpose: The optimal timing for starting oral anticoagulant after an ischemic stroke related to atrial fibrillation remains a challenge, mainly in patients treated with systemic thrombolysis or mechanical thrombectomy. We aimed at assessing the incidence of early recurrence and major bleeding in patients with acute ischemic stroke and atrial fibrillation treated with thrombolytic therapy and/or thrombectomy, who then received oral anticoagulants for secondary prevention. Methods: We combined the dataset of the RAF and the RAF-NOACs (Early Recurrence and Major Bleeding in Patients With Acute Ischemic Stroke and Atrial Fibrillation Treated With Non–Vitamin K Oral Anticoagulants) studies, which were prospective observational studies carried out from January 2012 to March 2014 and April 2014 to June 2016, respectively. We included consecutive patients with acute ischemic stroke and atrial fibrillation treated with either vitamin K antagonists or nonvitamin K oral anticoagulants. Primary outcome was the composite of stroke, transient ischemic attack, symptomatic systemic embolism, symptomatic cerebral bleeding, and major extracerebral bleeding within 90 days from the inclusion. Treated-patients were propensity matched to untreated-patients in a 1:1 ratio after stratification by baseline clinical features. Results: A total of 2159 patients were included, 564 (26%) patients received acute reperfusion therapies. After the index event, 505 (90%) patients treated with acute reperfusion therapies and 1287 of 1595 (81%) patients untreated started oral anticoagulation. Timing of starting oral anticoagulant was similar in reperfusion-treated and untreated patients (median 7.5 versus 7.0 days, respectively). At 90 days, the primary study outcome occurred in 37 (7%) patients treated with reperfusion and in 146 (9%) untreated patients (odds ratio, 0.74 [95% CI, 0.50–1.07]). After propensity score matching, risk of primary outcome was comparable between the 2 groups (odds ratio, 1.06 [95% CI, 0.53–2.02]). Conclusions: Acute reperfusion treatment did not influence the risk of early recurrence and major bleeding in patients with atrial fibrillation–related acute ischemic stroke, who started on oral anticoagulant.

Objective:\ud It is not known whether patients with atrial fibrillation (AF) with ischemic stroke despite oral anticoagulant therapy are at increased risk for further recurrent strokes or how ongoing secondary prevention should be managed.\ud \ud Methods:\ud We conducted an individual patient data pooled analysis of 7 prospective cohort studies that recruited patients with AF and recent cerebral ischemia. We compared patients taking oral anticoagulants (vitamin K antagonists [VKA] or direct oral anticoagulants [DOAC]) prior to index event (OACprior ) with those without prior oral anticoagulation (OACnaive ). We further compared those who changed the type (ie, from VKA or DOAC, vice versa, or DOAC to DOAC) of anticoagulation (OACchanged ) with those who continued the same anticoagulation as secondary prevention (OACunchanged ). Time to recurrent acute ischemic stroke (AIS) was analyzed using multivariate competing risk Fine-Gray models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).\ud \ud Results:\ud We included 5,413 patients (median age = 78 years [interquartile range (IQR) = 71-84 years]; 5,136 [96.7%] had ischemic stroke as the index event, median National Institutes of Health Stroke Scale on admission = 6 [IQR = 2-12]). The median CHA2 DS2 -Vasc score (congestive heart failure, hypertension, age≥ 75 years, diabetes mellitus, stroke/transient ischemic attack, vascular disease, age 65-74 years, sex category) was 5 (IQR = 4-6) and was similar for OACprior (n = 1,195) and OACnaive (n = 4,119, p = 0.103). During 6,128 patient-years of follow-up, 289 patients had AIS (4.7% per year, 95% CI = 4.2-5.3%). OACprior was associated with an increased risk of AIS (HR = 1.6, 95% CI = 1.2-2.3, p = 0.005). OACchanged (n = 307) was not associated with decreased risk of AIS (HR = 1.2, 95% CI = 0.7-2.1, p = 0.415) compared with OACunchanged (n = 585).\ud \ud Interpretation:\ud Patients with AF who have an ischemic stroke despite previous oral anticoagulation are at a higher risk for recurrent ischemic stroke despite a CHA2 DS2 -Vasc score similar to those without prior oral anticoagulation. Better prevention strategies are needed for this high-risk patient group.

This paper describes the development phases of a damping system for combustion instability reduction in an annular type combustor for heavy-duty gas turbine applications. As reported by the authors in a previous paper, the full scale annular test rig allowed for an extensive characterization of the combustor with realistic acoustic boundaries at engine-relevant conditions. Emissions and operability assessment over a wide range of load conditions was performed, allowing the evaluation of the response of the system near the thermo-acoustic instability onset. The instability is quantified by its acoustic growth rate. This quantity is a crucial input in the design process of dampers. A methodology has been used to extract these growth rates form measured pulsation data. Experimentally determined growth rates have been evaluated for different fuel flow rate split between the main and the pilot injections, providing input to dampers preliminary design. Given current combustor architecture constraints, a first attempt configuration has been proposed and performances evaluated in the full annular rig. Dampers have been equipped with dynamic sensors and thermocouples with the purpose of measuring the growth rate abatement and the consequent NOx emissions reduction. A dedicated numerical toolbox, in-house developed by GE Power, has been used for both dampers preliminary design and growth rate reduction evaluation. Fine tuning of dampers elements as well as design assumptions adjustments required additional experimental evaluations and design iterations. Encouraged by the successful test in the concept phase, an optimized design for engine implementation was defined, that featured a significant increased damper volume, involving combustor parts re-design. The optimized configuration was finally tested in full annular rig and results demonstrated an important enhancement of operability while maintaining NOx emissions below the target levels.

Introduction: Blood biomarkers have not been widely studied in stroke-related seizures. In this study, we aimed to describe clinical factors and biomarkers present during acute stroke and to analyze their association with early-onset seizures. Methods: We retrospectively evaluated a panel of 14 blood biomarkers in 1115 patients with ischemic and hemorrhagic stroke. Biomarkers were normalized and standardized using Z scores. We also recorded stroke and epilepsy-related variables, including stroke severity (National Institute of Health Stroke Scale [NIHSS] scores), type, and causes, timefromonset of stroke to occurrence of early seizures, and type of seizure. Adjusted logistic regression modelswere built to identify clinical variables and biomarkers independently associated with early seizures. Results: Mean +/- standard deviation (SD) age was 72.3 +/- 13.2 years, and 56.8% of the patients were men. Thirtyeight patients (3.9%) developed early seizureswith a median time to onset of 1 day (interquartile range (IQR), 04). A higher NIHSS score (odds ratio [OR] = 1.046; 95% confidence interval (CI): 1.001-1.094; p = 0.044) and hemorrhagic stroke (OR= 2.133; 95% CI: 1.010-4.504; p= 0.047) were independently associatedwith a greater risk of early seizures. Independent blood biomarkers predictive of early seizures were lower levels of tumor necrosis factor receptor 1 (TNF-R1) (0.326) (p= 0.009; OR = 2.625; 95% CI: 1.271-5.420). The predictive power of the regression model was greater when clinical variables were combined with blood biomarkers (73.5%; 95% CI: 65.1%-81.9%) than when used alone (64%; 95% CI: 55%-72.9%). Conclusion: Higher NCAM and lower TNF-R1 levels may help predict the occurrence of early seizures. The combined use of these biomarkers and clinical variables could be useful for identifying patients at risk of seizures. (C) 2019 Elsevier Inc. All rights reserved.

This study investigated whether functional transcranial Doppler ultrasound (fTCD) is a suitable tool for studying hemispheric lateralization of language in patients with pre-perinatal left hemisphere (LH) lesions and right hemiparesis. Eighteen left-hemisphere-damaged children and young adults and 18 healthy controls were assessed by fTCD and fMRI to evaluate hemispheric activation during two language tasks: a fTCD animation description task and a fMRI covert rhyme generation task. Lateralization indices (LIs), measured by the two methods, differed significantly between the two groups, for a clear LH dominance in healthy participants and a prevalent activation of right hemisphere in more than 80% of brain-damaged patients. Distribution of participants in terms of left, right, and bilateral lateralization was highly concordant between fTCD and fMRI values. Moreover, right hemisphere language dominance in patients with left hemispheric lesions was significantly associated with severity of cortical and subcortical damage in LH. This study suggests that fTCD is an easily applicable tool that might be a valid alternative to fMRI for large-scale studies of patients with congenital brain lesions.

Background The relationship between different patterns of atrial fibrillation and early recurrence after an acute ischaemic stroke is unclear. Purpose In a prospective cohort study, we evaluated the rates of early ischaemic recurrence after an acute ischaemic stroke in patients with paroxysmal atrial fibrillation or sustained atrial fibrillation which included persistent and permanent atrial fibrillation. Methods In patients with acute ischaemic stroke, atrial fibrillation was categorised as paroxysmal atrial fibrillation or sustained atrial fibrillation. Ischaemic recurrences were the composite of ischaemic stroke, transient ischaemic attack and symptomatic systemic embolism occurring within 90 days from acute index stroke. Results A total of 2150 patients (1155 females, 53.7%) were enrolled: 930 (43.3%) had paroxysmal atrial fibrillation and 1220 (56.7%) sustained atrial fibrillation. During the 90-day follow-up, 111 ischaemic recurrences were observed in 107 patients: 31 in patients with paroxysmal atrial fibrillation (3.3%) and 76 with sustained atrial fibrillation (6.2%) (hazard ratio (HR) 1.86 (95% CI 1.24–2.81)). Patients with sustained atrial fibrillation were on average older, more likely to have diabetes mellitus, hypertension, history of stroke/ transient ischaemic attack, congestive heart failure, atrial enlargement, high baseline NIHSS-score and implanted pacemaker. After adjustment by Cox proportional hazard model, sustained atrial fibrillation was not associated with early ischaemic recurrences (adjusted HR 1.23 (95% CI 0.74–2.04)). Conclusions After acute ischaemic stroke, patients with sustained atrial fibrillation had a higher rate of early ischaemic recurrence than patients with paroxysmal atrial fibrillation. After adjustment for relevant risk factors, sustained atrial fibrillation was not associated with a significantly higher risk of recurrence, thus suggesting that the risk profile associated with atrial fibrillation, rather than its pattern, is determinant for recurrence.

Background and Purpose- Bridging therapy with low-molecular-weight heparin reportedly leads to a worse outcome for acute cardioembolic stroke patients because of a higher incidence of intracerebral bleeding. However, this practice is common in clinical settings. This observational study aimed to compare (1) the clinical profiles of patients receiving and not receiving bridging therapy, (2) overall group outcomes, and (3) outcomes according to the type of anticoagulant prescribed. Methods- We analyzed data of patients from the prospective RAF and RAF-NOACs studies. The primary outcome was defined as the composite of ischemic stroke, transient ischemic attack, systemic embolism, symptomatic cerebral bleeding, and major extracerebral bleeding observed at 90 days after the acute stroke. Results- Of 1810 patients who initiated oral anticoagulant therapy, 371 (20%) underwent bridging therapy with full-dose low-molecular-weight heparin. Older age and the presence of leukoaraiosis were inversely correlated with the use of bridging therapy. Forty-two bridged patients (11.3%) reached the combined outcome versus 72 (5.0%) of the nonbridged patients (P=0.0001). At multivariable analysis, bridging therapy was associated with the composite end point (odds ratio, 2.3; 95% CI, 1.4-3.7; P0.0001), as well as ischemic (odds ratio, 2.2; 95% CI, 1.3-3.9; P=0.005) and hemorrhagic (odds ratio, 2.4; 95% CI, 1.2-4.9; P=0.01) end points separately. Conclusions- Our findings suggest that patients receiving low-molecular-weight heparin have a higher risk of early ischemic recurrence and hemorrhagic transformation compared with nonbridged patients.

The NovaLT™16 gas turbine recently developed in Baker Hughes, a GE company (BHGE), is part of a larger class of gas turbines (LT class) aiming at covering a wide space in the small power range segment and at introducing in the market a state of the art technology engine for what concerns performance, emissions, operability, durability and maintainability. The main purpose of this paper is to describe the entire validation campaign that was performed at BHGE facilities. This campaign can be divided into 3 different phases. The first phase focused on measuring engine performance in a new, clean and unaltered configuration. The second phase focused on emissions, vibration, thermal distribution, auxiliary system performances and the like, in order to validate the design assumption and calculation results across the full operational range. In this phase, more than 2000 sensors were installed across the entire engine, covering all modules, and all functional tests were performed (inside and outside of design space) to guarantee reliable engine behavior. At the end of this test phase, a full engine teardown was performed to allow a detailed parts inspection that confirmed the achievement of the design intent. The standard maintenance plan of the engine requires 35Kh continuous running. Therefore, the third part of the test aimed at validating engine durability with a full endurance test that allowed the identification and correction of any possible remaining operation problem. In this phase, the engine was still equipped with more than 1000 sensors, and was operated continuously following a well-defined operating profile in order to simulate both mechanical drive and power generation modes. This campaign successfully allowed to fine tune several engine control logic details, to monitor emissions behavior across a wide range of ambient temperature and load condition (the test spans from hot to cold day), to analyze trends of standard engine parameters and special instrumentation and, through planned borescope inspection, to evaluate individual component status versus selected operating profile. Data reported in this paper represent a summary of all the data acquired and post processing results, and illustrate how an endurance test can help tuning machine performance predictions in a wide operating range.

This paper describes the development phases of an annular type combustor for heavy-duty gas turbine applications. High cycle efficiency and low emissions are required over a wide range of load conditions, with the consequence of reducing margin to thermo-acoustic instability onset and lean blow-out. In addition, in lean premixed combustors, the increased fuel air mixing times required to keep emissions low, may lead to undesired ignition or flashback into the fuel burner ducts. All these aspects are matter of this work and focus is on fuel burner design modifications which allowed dry emissions reduction while maintaining a sufficiently wide safe operation window. A synergic effort has been put in place, involving experimental campaigns and CFD simulations, with the purpose of assessing design changes initially and doing screening. In the meanwhile, numerical practices have taken benefits form the experience growth. Results of past work on similar components has been leveraged too. Test campaign involved different scale facilities, from single burner through full annular combustor up to full scale prototype engine. The progressive reduction of viable option for combustor components design changes, due to high impact of such modifications during the gas turbine late development phases, forced designers to concentrate efforts onto fuel burner optimization, looking for efficient ways to implement modifications and assess their effectiveness of combustion system performances. Emissions trends, blow-out and flashback margin for several burner designs are reported. Numerical analysis results are also shown, which revealed to be well aligned with the experimental outcomes, allowing burner optimized solution to be identified. Finally, characterization with respect to fuel gas composition is shown as well as sensitivity to different operating conditions.

Cerebral sinus venous thrombosis (CSVT) is a rare condition representing the 0.5-1% of all stroke cases which can have serious consequences. Early diagnosis and complete screening for acquired or inherited risk factors is crucial for decreasing morbidity and mortality. We have investigated clinical and aetiological factors in an Italian cohort of 43 patients with cerebral sinus venous thrombosis. Common presentation complaints were headache (81.4%), focal signs (20.9%), vomiting (11.6%) and seizures (6.9%). Acquired or inherited conditions were observed in more than 80% of cases. The commonest aetiological factors were contraceptives (74.1% of women), congenital thrombophilia (34.9%), infections and dysthyroidism (16.3%), hyperhomocysteinemia (9.3%), migraine (11.6%), cranial trauma (9.3%) and chronic myeloproliferative diseases (11.6%). Outcome was favourable in more than 80% of patients. Early diagnosis and anticoagulant treatment may decrease mortality and/or morbidity rates related with CVST in these patients. Thrombophilic abnormalities, either inherited or acquired, are worthy to be widely investigated.

Background and Purposes— This study was designed to derive and validate a score to predict early ischemic events and major bleedings after an acute ischemic stroke in patients with atrial fibrillation. Methods— The derivation cohort consisted of 854 patients with acute ischemic stroke and atrial fibrillation included in prospective series between January 2012 and March 2014. Older age (hazard ratio 1.06 for each additional year; 95% confidence interval, 1.00–1.11) and severe atrial enlargement (hazard ratio, 2.05; 95% confidence interval, 1.08–2.87) were predictors for ischemic outcome events (stroke, transient ischemic attack, and systemic embolism) at 90 days from acute stroke. Small lesions (≤1.5 cm) were inversely correlated with both major bleeding (hazard ratio, 0.39; P =0.03) and ischemic outcome events (hazard ratio, 0.55; 95% confidence interval, 0.30–1.00). We assigned to age ≥80 years 2 points and between 70 and 79 years 1 point; ischemic index lesion >1.5 cm, 1 point; severe atrial enlargement, 1 point (ALESSA score). A logistic regression with the receiver-operating characteristic graph procedure (C statistic) showed an area under the curve of 0.697 (0.632–0.763; P =0.0001) for ischemic outcome events and 0.585 (0.493–0.678; P =0.10) for major bleedings. Results— The validation cohort consisted of 994 patients included in prospective series between April 2014 and June 2016. Logistic regression with the receiver-operating characteristic graph procedure showed an area under the curve of 0.646 (0.529–0.763; P =0.009) for ischemic outcome events and 0.407 (0.275–0.540; P =0.14) for hemorrhagic outcome events. Conclusions— In acute stroke patients with atrial fibrillation, high ALESSA scores were associated with a high risk of ischemic events but not of major bleedings.

Endovascular procedures are a less invasive revascularization strategies than endoarterectomy for carotid stenosis, but to date Guidelines recommend surgery for a major periprocedural safety. Evidences come from randomized studies where operator’s experience in endovascular group was not considered. We retrospectively evaluated 524 endovascular procedures (carotid angioplasty ± stenting, CAS) performed between 1996 and 2010 on 486 patients (mean age 71.3 ± 7.8 years) with symptomatic or asymptomatic carotid stenosis from a single center. We evaluated efficacy (residual stenosis ≤30 % after postprocedural angiography) and safety [minor (TIAs or myocardial infarcts) and major (stroke or death) complications in the first 30 days] of procedures and correlated them with the increasing experience of the operator. CAS was successful in 504/524 cases (96.2 %); unsuccessful procedures occurred more frequently in case of angioplasty alone rather than angioplasty and stenting (13/61, 21.3 % vs. 7/463, 1.5 %, OR 17.64, 95 % CI 6.69–46.06). 17/524 (3.2 %) CAS met the combined safety endpoint: stroke in 2.4 % and death in 0.8 %; the rate of disabling stroke/death was 1.6 %. Center experience was inversely related to the rate of stroke/death (R 2 = 0.9375), passing from 5.0 % after 100 CAS to 2.8 % after 500 CAS; for disabling stroke/death (R 2 = 0.9386), the rate was 4 % after 100 CAS and 1.6 % after 500 CAS. CAS is an effective and safe revascularization procedure in both symptomatic and asymptomatic patients, if effected in experienced centers. The use of carotid artery stenting than angioplasty alone and emboli protection devices can much more improve the previous considerations.

Diagnostic rules for online monitoring of turbocompressor trains driven by gas turbines are presented. These rules cover components and zones that are most susceptible to failure, such as combustion elements, hot-gas-path- exposed wheelspace area, and dry gas seal components. The effect of these rules on improving the availability and reliability of such machines are also explained. Various case studies using real operational data are shown, and emphasis is given to explaining how to use the rules in diagnostic and prognostic studies. The rules can be divided into availability and performance rules. For the gas turbine, engineering performance rules covering the axial compressor, output parameters, and fuel consumption are introduced. Availability rules covering combustion and the wheelspace temperature are discussed after that. For the centrifugal compressor, rules covering the dry gas seal components are presented. Both theoretical and practical considerations are given to optimize the rules' output in terms of accuracy, ease of implementation, and value to the end user. All presented rules are based on physics and probabilistic methods and are not based on simple thresholds.

Fuel flexibility is a key feature for Dry Low NOx (DLN) combustors, which shall be capable of accepting a wider range of fuel compositions to meet more and more challenging requests from the Oil and Gas market segment (upstream and downstream applications). Non-methane hydrocarbons (C2+) are one of the main targets of GE Oil & Gas efforts to enlarge the fuel flexibility of DLN combustors, as they are often present in high concentration in fuel gas streams that customers would like their gas turbine to be fed with. The main concerns with such fuel gases in DLN combustor are: the risks of flashback, hardware overheating, increased combustion dynamics and NOx emission, ignition in unexpected locations (with potential damage of the combustor, operability issues and impact on durability). In order to assess the capability of the current Frame 5 DLN1 hardware design with high C2+ fuels, a single can full pressure test campaign was conducted on a full size DLN1 combustor at Sesta Combustion Lab (Italy). The combustion chamber was successfully tested in premix mode up to 50%v. of ethane content, observing safe and reliable operation with regard to the above mentioned risks. Special tests were carried out in both Premix and Lean-Lean operating modes, in order to verify the ability of the combustor to maintain a stable and harmless flame and assess the operability margins in the different operating conditions of the combustor. Tests demonstrated a good margin already with the current design. After optimizing the air flow path, the expected performances also in terms of NOx and CO emissions and combustion dynamics were achieved in the investigated ethane content range. These tests outcomes allowed a paramount enlargement of the Frame 5 DLN1 capability in terms of acceptable C2+ concentration in fuel gas.

The optimization of the heat recovery steam generator (HRSG) is one of the key elements for increasing the efficiency of combined plants. According to the current technical practice, it can be organized at different levels of complexity with objectives sequentially defined: operating parameters, geometrical details and technological elements. According to this point of view, in the paper a complete strategy for the optimum design of the HRSG is outlined. The optimization is organized at two levels: the first one enables to obtain the main operating parameters of the HRSG, while the second involves the detailed design of the component concerning the geometric variables of the heat transfer sections. The output of the first-level optimization is the input of the second level. In particular, the second level of the optimization can be articulated in two different steps. The first step can be aimed to the minimization of the pressure drop for a given heat flow. The second step leads to a reduction of the overall dimensions, maintaining the imposed performance of the HRSG in terms of heat flow and pressure drop. The whole procedure is tested with reference to a case of existing HRSG structures; it shows the possibility of improving performance maintaining a constrained packaged size.

The paper analyzes the perspectives of biomass and biomass derived fuels utilization for energetic use. After a brief review about the current technologies for biomass conversion to energy and biomass based power plants, an exergy loss based economic analysis of biomass utilization is proposed. This analysis shows the opportunity of using biomass in plants with a thermodynamic efficiency higher than a minimum value. Thus the attention is focused on the use of thermal energy from biomass as integrative source together with natural gas in combined cycle power plants, considering methods for upgrading biomass energy conversion to power. The paper provides a thermodynamic analysis of combined plants using biomass to obtain exhaust gas aftertreatment with atmospheric postcombustion (reheat). Two different technical solutions are proposed. A general optimization of the two solutions shows the possibility of obtaining plant efficiency up to 60% in perspective and of 57% by using currently available gas turbine models.

This work was aimed at measuring the resulting electric forces acting on a gas bubble growing quasistatically, with gas supplied to it through a circular orifice, and to compare them with their theoretical counterparts. An experimental apparatus has been set up, consisting essentially of an orifice drilled in a flat stainless steel plate submerged in the test fluid (FC-72). A dedicated gas injection system allowed creating slowly growing or even static bubbles of any desired volume, up to the detachment volume. An electric field could be imposed by means of a washer-shaped electrode laid parallel to the surface and centered on the orifice. The apparatus could be operated with the orifice both in upward and in downward direction to investigate the favorable or adverse role of the buoyancy force. Data were acquired via a highresolution video camera, equipped with a microscopic lens, and were digitized and processed via dedicated software, implemented in Matlab. The resulting forces acting on the bubbles were derived from bubble shape and size. The data in the absence of electric field were compared with their theoretical counterpart to validate the method and the image processing technique and showed an excellent agreement. In a second phase, data with electric field were acquired. The resulting electric force was evaluated from the force balance, as the opposite of the sum of all the other forces acting on the bubble. The values of measured electric forces showed excellent agreement with the theoretical evaluations.

Background Basing on easily available clinical and instrumental data, we aimed to define an “atrial fibrillation profile” able to discriminate cases of stroke due to atrial fibrillation from cases due to atherothrombosis of large vessels or small-vessel disease. Methods A total of 1037 consecutive patients with ischemic stroke were enrolled. Cases with undetermined stroke, rare causes, and cardioembolic sources of emboli other than atrial fibrillation were excluded from further analysis. Thus, 653 patients were evaluated, dividing them into 2 groups for comparison (164 with stroke due to atrial fibrillation and 489 with atherothrombotic/lacunar stroke). Clinical, echocardiography, and neuroradiologic data were considered to characterize such groups. Results Atrial fibrillation and atherothrombotic–lacunar group presented a differential phenotypic profile. Binary multiple logistic regression identified age older than 75 years, female sex, left atrial dilation, cortical–subcortical cerebral index infarct, ischemic lesions in multiple vascular grounds, and spontaneous hemorrhagic transformation of brain infarction as significant predictors of cardioembolic stroke due to atrial fibrillation. Conclusions A simple profile, based on commonly available data, seems suitable to characterize patients with stroke due to atrial fibrillation. If further validated, it may be useful to identify patients with undetermined stroke (or other well-defined causes of stroke) at high risk of being affected by undetected subclinical paroxysmal atrial fibrillation, prompting further diagnostic work-up and with potential therapeutic implication.

Background Stroke may be a clinical expression of several inherited disorders in humans. Recognition of the underlined genetic disorders causing stroke is important for a correct diagnosis, for genetic counselling and, even if rarely, for a correct therapeutic management. Moreover, the genetics of complex diseases such the stroke, in which multiple genes interact with environmental risk factors to increase risk, has been revolutionized by the Genome-Wide Association Study (GWAS) approach. Scope of review Here we review the single-gene causes of ischemic stroke, bringing the reader from the candidate gene method toward the exciting new horizons of genetic technology. Major conclusions The aetiological diagnosis of ischemic stroke in young adults is more complex than in the elderly. The identification of a genetic cause is important to provide appropriate counseling and to start a correct therapy, when available. The advent of GWAS technology, such as for other complex pathological conditions, has contributed enormously to the understanding of many of these genetic bases. For success large, well phenotyped case cohorts are required, and international collaborations are essential. General significance This review focuses on the main causes of genetically-based ischemic stroke in young adults, often classified as indeterminate, investigating also the recent findings of the GWAS, in order to improve diagnostic and therapeutic management., Highlights • The aetiological diagnosis of stroke in young adults needs a different and more complex diagnostic work up than in older adults. • Stroke may be a clinical expression of several inherited disorders in humans. • The most common genetic causes of stroke are CADASIL, Fabry and mitochondrial diseases. • Recognition of the underlined genetic disorders causing stroke is important for the correct management of the patient.

Functional Transcranial Doppler ultrasonography (fTCD) was used to investigate the effects of early acoustic deprivation and subsequent reafferentation on cerebral dominance for language in deaf children provided with Cochlear Implantation (CI). Twenty children with CI (13 in right ear and 7 in left ear) and 20 controls matched for age, sex and handedness were administered a fTCD animation description task. Left hemisphere dominance for language with comparable mean Laterality Indexes (LIs) was found in children with CI and controls; right-ear implanted subjects showed cerebral activation controlateral to implanted ear more frequently than left-ear implanted ones. Linguistic proficiency of CI recipients was below age expectation in comparison to controls; language scores did not significantly differ between children with left and right LI, whereas both age and side of implantation were significantly related to language outcome. Theoretical implication and potential clinical application of fTCD in CI management are discussed.

To the Editor: We read with great interest the article of Kahlert et al1 that confirms the role of transcatheter aortic valve implantation as a safe procedure, performable on patients at high operatory risk who cannot undergo traditional surgical aortic valve replacement, and evidences the role of transcranial Doppler procedural monitoring to detect microembolic signals generated by the fragmentation …

Acute basilar artery occlusion has a poor prognosis and best treatment has not been assessed yet; as for intra-arterial treatment, no “gold standard” exists. We evaluated a series of ten patients treated with intra-arterial combination of recombinant tissue plasminogen activator (rtPA) and abciximab. Partial/complete recanalisation was achieved in all patients and good outcome (1 month Modified Rankin Scale 0–2) in eight cases, while one patient had symptomatic intracranial haemorrhage and died. Such outcome appears significantly better if compared with the results of Basilar Artery International Cooperation Study, suggesting that intra-arterial administration of rtPA and abciximab may be a promising option in patients with acute basilar artery occlusion undergoing endovascular treatment.

Transient ischemic attack or ischemic stroke in hereditary hemorrhagic telangiectasia (HHT), a rare genetic disease, is frequent in clinical practice and often associated to pulmonary arteriovenous malformations (PAVMs), potentially determining paradoxical cerebral embolism. We describe the case of a 53-year-old woman with a previous history of recurrent epistaxis, admitted to our unit for a transient episode of diplopia and unbalance. Cerebrovascular screening showed the presence of a right to left shunt at saline contrast transcranial Doppler, related to 3 PAVMs detected by subsequent chest computed tomographic scan. Genetic screening evidenced deletion in endoglin gene (ENG), suggesting diagnosis of HHT type 1. Secondary cerebrovascular prevention with antithrombotic therapy was early stopped for the worsening of epistaxis. Neurologic symptoms are common in HHT, and saline contrast transcranial Doppler can be a reliable alternative to echocardiography for detection of right to left shunt commonly related to underlying PAVMs.

Today’s Oil & Gas facility market requires enlarging machines’ fuel flexibility toward two main directions: on the one hand burning fuels with high percentages of Ethane, Butane and Propane, on the other hand burning very lean fuels with a high percentage of inerts. GE has extensive experience in burning a variety of gas fuels and blends in heavy-duty gas turbines. From a technical point of view, the tendency towards leaner fuel gases for feeding gas turbines, introduces potential risks related to combustion instability, on both combustion hardware and machines’ operability. GE Oil&Gas (Nuovo Pignone), has developed a new program aimed to extend the fuel flexibility of its Low-NOx diffusion flame combustor (Lean Head End, or LHE), which currently equips single and dual shaft 30 MW gas turbines, so that it can handle low-LHV fuels. A fuel flexibility test campaign was carried out at full and partial load conditions over an ambient and fuel range, in order to investigate both ignition limits and combustor performances, focusing on hot parts’ temperatures, pollutant emissions and combustion driven pressure oscillations. The pressurized tests were performed on a single combustion chamber, using a dedicated full-scale (full-pressure, full-temperature and full-flow) combustor test cell. Variable composition gaseous fuel mixtures, obtained by mixing natural gas with N2 from 0% up to about 50% vol., were tested. The experienced LHE combustion system up to now had been fed only with natural gas in multi can single gas combustion systems. Combustion system modifications and different burner configurations were considered to enlarge system capabilities, in order to accommodate operation on the previous mentioned range of fuel mixtures, including: nozzle orifice sizing and combustor liner modification. This paper aims to illustrate the upgraded technology and the results obtained. Reported data show combustion system’s performances, mainly in terms of pollutant emissions and operability. The performed test campaign demonstrated the system’s ability to operate at all required loads with diluted natural gases containing up to 50% vol. of N2. Results also indicate that ignition is possible with the same inerts concentration in the fuel, keeping the fuel flow at moderately low levels. As far as load operation, the combustion system proved to be almost insensitive to any tested inerts concentration, while a huge reduction of NOx emissions was observed increasing the molar fraction of N2 in the fuel gas, maintaining good flame stability.

The paper analyses the use of a particular kind of compact heat exchanger (CHE), a plate-fin heat exchanger (PFHE), conceptually based upon the cross-flow heat exchangers. The use of this compact heat exchanger can be proposed to obtain basic modular element for the construction of small size heat recovery steam generators (HRSG), in order to achieve efficiency increase and reduction of size by means of various packaging solutions. With reference to the use of such particular HRSG structure, a method for the optimum thermal design of the HRSG and of each single section is outlined. The optimization is structured in two main levels: the higher level enables to define the main operating parameters of the HRSG, while the second involves the detailed design of the PFHE heat transfer surfaces. The attention is mainly focused on the second optimization level, which is articulated in two steps. The objective of the first step is the minimization of the pressure drop for a given heat flow. At the second step the minimization of the weight, maintaining the imposed HRSG performance in term of heat flow and pressure drop, is performed. The method is tested with reference to a basic 1.5 MW double pressure HRSG structure demonstrating the possibility of obtaining interesting increase of the performance with respect to a usual design method.

Stroke is a complex disease resulting from the interplay of genetics and environment. In some instances (mainly in young adults) stroke is the direct result of a monogenic disease. Among the monogenic causes of stroke, the diseases which are most frequently encountered in the adult general neurological practice are CADASIL, Fabry and mitochondrial diseases. Brain MRI and clinical features may frequently lead to a correct molecular diagnosis. Here we review the single-gene causes of ischemic stroke, with special regard to the associated features which may help in the diagnostic approach.