Second asymptomatic carotid surgery trial (ACST-2): a randomised comparison of carotid artery stenting versus carotid endarterectomy

Background: Among asymptomatic patients with severe carotid artery stenosis but no recent stroke or transient cerebral ischaemia, either carotid artery stenting (CAS) or carotid endarterectomy (CEA) can restore patency and reduce long-term stroke risks. However, from recent national registry data, each option causes about 1% procedural risk of disabling stroke or death. Comparison of their long-term protective effects requires large-scale randomised evidence. Methods: ACST-2 is an international multicentre randomised trial of CAS versus CEA among asymptomatic patients with severe stenosis thought to require intervention, interpreted with all other relevant trials. Patients were eligible if they had severe unilateral or bilateral carotid artery stenosis and both doctor and patient agreed that a carotid procedure should be undertaken, but they were substantially uncertain which one to choose. Patients were randomly allocated to CAS or CEA and followed up at 1 month and then annually, for a mean 5 years. Procedural events were those within 30 days of the intervention. Intention-to-treat analyses are provided. Analyses including procedural hazards use tabular methods. Analyses and meta-analyses of non-procedural strokes use Kaplan-Meier and log-rank methods. The trial is registered with the ISRCTN registry, ISRCTN21144362. Findings: Between Jan 15, 2008, and Dec 31, 2020, 3625 patients in 130 centres were randomly allocated, 1811 to CAS and 1814 to CEA, with good compliance, good medical therapy and a mean 5 years of follow-up. Overall, 1% had disabling stroke or death procedurally (15 allocated to CAS and 18 to CEA) and 2% had non-disabling procedural stroke (48 allocated to CAS and 29 to CEA). Kaplan-Meier estimates of 5-year non-procedural stroke were 2·5% in each group for fatal or disabling stroke, and 5·3% with CAS versus 4·5% with CEA for any stroke (rate ratio [RR] 1·16, 95% CI 0·86–1·57; p=0·33). Combining RRs for any non-procedural stroke in all CAS versus CEA trials, the RR was similar in symptomatic and asymptomatic patients (overall RR 1·11, 95% CI 0·91–1·32; p=0·21). Interpretation: Serious complications are similarly uncommon after competent CAS and CEA, and the long-term effects of these two carotid artery procedures on fatal or disabling stroke are comparable. Funding: UK Medical Research Council and Health Technology Assessment Programme

Restless legs syndrome in patients on hemodialysis: Frequency, severity and risk factors

Objective. Restless legs syndrome is a neurologic disorder which especially affects patients on hemodialysis. The aim of our study was to estimate the frequency and severity of restless legs syndrome in hemodialysis patients' population and explore possible connection with some factors by analyzing differences in patients' sociodemographic characteristics, existence and severity of coexistent diseases, biochemical parameters and dialysis type between the patients with and without this syndrome. Methods. 96 subjects were included in our crosssectional study. The diagnosis of restless legs syndrome was made by using criteria of International Restless Legs Study Group. Severity of the syndrome was evaluated through the use of Restless Legs Syndrome Rating Scale questionnaire. Results. Restless legs syndrome was found in 39.6% of subjects. The most of patients had moderate (36.8%) or severe symptoms (50%). There was no statistically significant difference between the patients with and without restless legs syndrome regarding sociodemographic and biochemical characteristics and dialysis type. In terms of coexistent disease, it was found that patients with restless legs syndrome had a significantly greater frequency of ischemic heart disease and depression compared to the patients without the syndrome. There was no difference in index of coexistent disease. Severity of depression and insomnia was higher in patients with restless legs syndrome. Conclusion. This study confirmed that restless legs syndrome is very frequent in hemodialysis patients and indicated that even two-third of patients had severe to very severe symptoms. For future research, it is necessary to direct attention to influence of comorbidity in hemodialysis patient on restless legs syndrome, especially on influence of psychiatric disorders

Forced response variation of aerodynamically and structurally mistuned turbo-machinery rotors

The paper presents the results of a study looking into changes in the forced response levels of bladed disc assemblies subject to both structural and aerodynamic mistuning. A whole annulus FE model, representative of a civil aero-engine fan with 26 blades was used in the calculations. The forced response of all blades of 1000 random mistuned patterns was calculated. The aerodynamic parameters, frequency shifts and damping, were calculated using a three-dimensional Reynolds-averaged Navier-Stokes aero-elasticity code. They were randomly varied for each mistuning pattern, with the assumption that the system would remain stable, i.e. flutter would not occur due to aerodynamic mistuning. The results show the variation of the forced response with different types of mistuning, with structural mistuning only, with aerodynamic mistuning only and with both structural and aerodynamic mistuning

Investigation of the influence of aerodynamic coupling on response levels of mistuned bladed discs with weak structural coupling

The paper summarises the results of a study investigating the correlation between the aerodynamic blade-to-blade coupling in mistuned bladed disc assemblies and the level of forced response. The focus was placed on the torsional mode of vibration, where blades' coupling through the disc is weak, exposing the effects of aerodynamic coupling. The forced response of a large number of mistuned discs was computed, using whole-annulus finite element (FE) models. The unsteady aerodynamic forces that act upon the disc were calculated using a three-dimensional Reynolds-averaged Navier-Stokes CFD code. The results show the difference in response with and without aerodynamic coupling, exposing higher blade-to-blade interaction in the latter case. The statistical results show the change of the forced response distribution curves with the introduction of aero-coupling and their deviation from Gaussian distributio

Decreased Thromboembolic Stroke but not Atherosclerosis or Vascular Remodeling in Mice with ROCK2-deficient Platelets

Aims: Rho-associated coiled-coil containing kinase (ROCK)-2 is an important mediator of the actin cytoskeleton. Because changes in the actin cytoskeleton are critical for platelet function, we hypothesized that ROCK2 in platelets will play important role in thrombosis and can be potentially a target for therapeutic intervention in thromboembolic stroke. Methods and Results: We generated platelet-specific ROCK2-deficient mice (ROCK2 Plt-/- ) from conditional ROCK2 fl degrees x/fl degrees x and platelet factor (PF)-4-Cre transgenic mice. Platelets from ROCK2 Plt-/- mice were less responsive to thrombin stimulation in terms of pseudopodia formation, collagen adhesion, and in the formation of homotypic and heterotypic aggregates. This corresponded to prolonged bleeding time and delayed vascular occlusion following vessel injury. To determine whether these changes in platelet function could affect thrombotic disease, we utilized a clot-embolic model of ischemic stroke. When pre-formed clots from ROCK2 Plt-/- mice were injected into the middle cerebral artery of control mice, cerebral blood flow recovery occurred more rapidly, leading to decreased cerebral injury and neurological deficits, compared to pre-formed clots from control mice. Interestingly, pre-formed clots from control mice produced similar degree of cerebral injury when injected into control or ROCK2 Plt-/- mice, suggesting that platelet ROCK2 deficiency affects clot formation but not propagation. Indeed, in a non-thrombotic intra-filament MCA occlusion model of stroke, platelet ROCK2 deletion was not protective. Furthermore, ROCK2 Plt-/- mice exhibit similar atherosclerosis severity and vascular remodeling as control mice. Conclusion: These findings indicate that platelet ROCK2 plays important role in platelet function and thrombosis, but does not contribute to the pathogenesis of atherosclerosis and vascular remodeling

Data Augmentation for Plant Classification

Data augmentation plays a crucial role in increasing the number of training images, which often aids to improve classification performances of deep learning techniques for computer vision problems. In this paper, we employ the deep learning framework and determine the effects of several data-augmentation (DA) techniques for plant classification problems. For this, we use two convolutional neural network (CNN) architectures, AlexNet and GoogleNet trained from scratch or using pre-trained weights. These CNN models are then trained and tested on both original and data-augmented image datasets for three plant classification problems: Folio, AgrilPlant, and the Swedish leaf dataset. We evaluate the utility of six individual DA techniques (rotation, blur, contrast, scaling, illumination, and projective transformation) and several combinations of these techniques, resulting in a total of 12 data-augmentation methods. The results show that the CNN methods with particular data-augmented datasets yield the highest accuracies, which also surpass previous results on the three datasets. Furthermore, the CNN models trained from scratch profit a lot from data augmentation, whereas the fine-tuned CNN models do not really profit from data augmentation. Finally, we observed that data-augmentation using combinations of rotation and different illuminations or different contrasts helped most for getting high performances with the scratch CNN models

The role of pericytes in brain disorders: from the periphery to the brain

It is becoming increasingly apparent that disorders of the brain microvasculature contribute to many neurological disorders. In recent years it has become clear that a major player in these events is the capillary pericyte which, in the brain, is now known to control the blood-brain barrier, regulate blood flow, influence immune cell entry and be crucial for angiogenesis. In this review we consider the under-explored possibility that peripheral diseases which affect the microvasculature, such as hypertension, kidney disease and diabetes, produce central nervous system (CNS) dysfunction by mechanisms affecting capillary pericytes within the CNS. We highlight how cellular messengers produced peripherally can act via signalling pathways within CNS pericytes to reshape blood vessels, restrict blood flow or compromise blood-brain barrier function, thus causing neuronal dysfunction. Increased understanding of how renin-angiotensin, Rho-kinase and PDGFRβ signalling affect CNS pericytes may suggest novel therapeutic approaches to reducing the CNS effects of peripheral disorders