14 research outputs found

    Active Vorticity Control in a Shear Flow Using a Flapping Foil

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    It is shown experimentally that free shear flows can be substantially altered through direct control of the large coherent vortices present in the flow

    Absolute instabilities and self-sustained oscillations in the wake of circular cylindars

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    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Depression and anxiety in epilepsy: The association with demographic and seizure-related variables

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    Background: Depression and anxiety are common psychiatric symptoms in patients with epilepsy, exerting a profound negative effect on health-related quality of life. Several issues, however, pertaining to their association with psychosocial, seizure-related and medication factors, remain controversial. Accordingly, the present study was designed to investigate the association of interictal mood disorders with various demographic and seizure-related variables in patients with newly-diagnosed and chronic epilepsy. Methods: We investigated 201 patients with epilepsy (51.2% males, mean age 33.2 ± 10.0 years, range 16-60) with a mean disease duration of 13.9 ± 9.5 years. Depression and anxiety were assessed in the interictal state with the Beck Depression Inventory, 21-item version (BDI-21) and the state and trait subscales of the State-Trait Anxiety Inventory (STAI-S and STAI-T), respectively. The association of mood disorders with various variables was investigated with simple and multiple linear regression analyses. Results: High seizure frequency and symptomatic focal epilepsy (SFE) were independent determinants of depression, together accounting for 12.4% of the variation of the BDI-21. The STAI-S index was significantly associated with the type of epilepsy syndrome (SFE). Finally, high seizure frequency, SFE and female gender were independent determinants of trait anxiety accounting for 14.7% of the variation of the STAI-T. Conclusion: Our results confirm the prevailing view that depression and anxiety are common psychological disorders in epileptics. It is additionally concluded that female gender, high seizure frequency and a symptomatic epilepsy syndrome are independent risk factors for the development of anxiety and/or depression. © 2007 Kimiskidis et al; licensee BioMed Central Ltd

    Stroke recurrence and mortality in northeastern Greece: the Evros Stroke Registry

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    Up to date there is no population-based study from Greece providing long-term data on incidence of both all-cause mortality and stroke recurrence for patients with first ever stroke (FES). Adult patients with FES were registered during a 24-month period (2010–2012) and followed-up for 12 months. We calculated cumulative incidences of stroke mortality and recurrence. Univariable and multivariable Cox proportional hazards regression analyses were used to identify independent determinants of 1-year mortality and 1-year stroke recurrence. We prospectively documented 703 first ever stroke cases (mean age 75 ± 12 years; 52.8% males; ischemic stroke 80.8%, intracerebral hemorrhage 11.8%, subarachnoid hemorrhage 4.4%, undefined 3.0%) with a total follow-up time of 119,805 person-years. The cumulative incidence rates of mortality of all FES patients at 28 days, 3 months and 1 year were 21.3% (95% CI 18.5–24.5%), 26% (95% CI 22.9–29.4%) and 34.7% (95% CI 31.3–38.3%), respectively. The risk of 1-year mortality was independently (p < 0.05) associated with advancing age, history of hypertension, increased stroke severity on admission, and hemorrhagic FES type. Cumulative 1-year stroke mortality differed according to both index FES type (ischemic vs. hemorrhage; p < 0.001), but also across different ischemic stroke subtypes (p = 0.025). The cumulative incidence rates of recurrent stroke at 28 days, 3 months and 1 year were 2.0% (95% CI 1.2–3.6%), 4.2% (2.8–6.2%) and 6.7% (5.1–8.8%), respectively. Comparable to other population-based surveys, our study reports 1-year mortality and stroke recurrence rates in patients with FES. These findings highlight the need for effective secondary prevention strategies in a border region of southeastern Europe, which exhibits very high FES incidence rates. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature

    Analysis of non-symmetrical flapping airfoils

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    10.1007/s10409-009-0259-1Acta Mechanica Sinica/Lixue Xuebao254433-450AMSN

    Risk of perioperative neck hematoma in TIA and non-disabling stroke patients with symptomatic carotid artery stenosis undergoing endarterectomy within 14 days from cerebrovascular event.

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    Backround & purpose: Perioperative neck hematoma (PNH) requiring re-intervention is an important complication after carotid endarterectomy (CEA). There are limited data regarding the potential risk factors associated with PNH. The aim of this prospective, multicenter study was to document the rate of PNH in symptomatic carotid artery stenosis (sCAS) patients treated with CEA within the first 14 days of cerebrovascular symptom onset and to identify possible predictors of this complication. Methods: Patients with non-disabling (mRS ≤ 2) acute ischemic stroke or transient ischemic attack due to sCAS (≥70%) underwent CEA at three stroke-centers during a seven-year period. PNH requiring surgical re-intervention or transfusion during a 30-day follow-up period was determined by the attending surgeon but was also confirmed by an independent neurologist. Results: A total of 280 patients with sCAS underwent CEA within 14 days of ictus. PNH occurred in 10 cases (3.6%; 95%CI: 1.4%–5.8%). Pretreatment with therapeutic anticoagulation (TA) and history of atrial fibrillation were more prevalent in patients with PNH (20% vs. 3.1%, p= 0.047 & 30% vs. 8.2%, p = 0.05 respectively). Elapsed time between symptom onset and carotid surgery, pretreatment with dual antiplatelets, intravenous thrombolysis or prophylactic anticoagulation were not related to PNH in univariable analyses. Pretreatment with TA was independently associated with higher likelihood of PNH [OR: 10.69, 95%CI (1.74–65.72), p = 0.011] in multivariate logistic regression models adjusting for potential confounders. Conclusion: PNH is uncommon in patients with sCAS that are operated during the first 14 days of ictus. Pretreatment with TA appears to be associated with higher risk of PNH. © 2019 Elsevier B.V

    Clinical and Neuroimaging Characteristics in Embolic Stroke of Undetermined versus Cardioembolic Origin: A Population-Based Study

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    BACKGROUND AND PURPOSE: Evidence suggests that cardioembolism represents the underlying mechanism in the minority of embolic strokes of undetermined source (ESUS). In this population-based study, we sought to compare the clinical and imaging characteristics as well as outcomes in patients with ESUS and cardioembolic stroke (CE). METHODS: We included consecutive patients with first-ever ischemic stroke (IS) from the previously published population-based Evros-Stroke-Registry identified as ESUS or CE according to standardized criteria. Baseline characteristics, admission NIHSS scores, cerebral edema, hemorrhagic transformation, stroke recurrence, functional outcomes (determined by modified Rankin Scale [mRS] scores), and mortality rates were recorded during the 1-year follow-up period. RESULTS: We identified 21 ESUS (3.7% of IS) and 211 CE (37.1% of IS) cases. Patients with ESUS were younger (median age: 68 years [interquartile range [IQR]: 61-75] vs 80 years [IQR: 75-84]; P <.001), had lower median admission NIHSS scores (4 points [IQR: 2-8] vs 10 points [IQR: 5-17]; P <.001), and lower prevalence of cerebral edema on neuroimaging studies (0 vs. 33.3%, P =.002). Functional outcomes were more favorable in ESUS at 28 (median mRS score: 2 [IQR: 1-3] vs 4 [IQR: 4-5]; P <.001), 90 (median mRS score: 1 [IQR: 0-2] vs 4 [IQR: 3-5]; P <.001), and 365 days (median mRS score: 1 [IQR: 0-2] vs 4 [IQR: 2-4]; P < 0.001). At 1-year, the mortality rate was lower in ESUS (0% [95% confidence interval [CI]: 0-13.5%] vs 34.6% [95% CI: 28.2-41.0%]; P <.001); the 1-year recurrent rate was also lower numerically (0% [95% CI: 0-13.5%] vs 9.5% [95% CI: 5.5-13.4%]; P =.140) but this difference failed to reach statistical significance due to the small study population. CONCLUSIONS: The clinical and neuroimaging profiles as well as clinical outcomes vary substantially between ESUS and CE indicating different underlying mechanisms. © 2019 by the American Society of Neuroimagin
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