The effect of applied magnetic field on photocurrent generation in poly-3-hexylthiophene:[6,6]-phenyl C61-butyric acid methyl ester photovoltaic devices

This is the author’s version of a work that was accepted for publication in Journal of Physics: Condensed Matter http://dx.doi.org/10.1088/0953-8984/20/45/45220

Relation between physical activity and cerebral small vessel disease: A nine-year prospective cohort study.

BACKGROUND AND AIMS: Given the unexplored potential of physical activity to reduce the progression of cerebral small vessel disease (cSVD, the purpose of this study was to prospectively (across nine-year follow-up) examine the relation between (baseline) physical activity and the (clinical and imaging) consequences of the whole spectrum of cerebral small vessel disease. METHODS: Five hundred and three patients with cerebral small vessel disease from the RUNDMC study were followed for nine years. Physical activity was assessed using a questionnaire in 2006, 2011, and 2015. Clinical events (i.e. all-cause mortality, cerebrovascular events (by stroke subtype)) were collected with a structured questionnaire. Patients underwent magnetic resonance imaging scanning for the assessment of magnetic resonance imaging markers of cerebral small vessel disease (i.e. white matter hyperintensities, lacunes, and microbleeds) and microstructural integrity of the white matter at three timepoints. RESULTS: The mean age at baseline was 66 (SD 9.0) years; 44% were women. A higher baseline physical activity level was independently associated with a lower all-cause mortality (HR: 0.69, 95%CI: 0.49-0.98, p = 0.03) and incidence of cerebrovascular disease (HR: 0.58, 95%CI: 0.36-0.96, p = 0.03). However, we found no relation between physical activity and incident lacunar stroke or progression of magnetic resonance imaging markers of cerebral small vessel disease. CONCLUSIONS: Whilst regular physical activity was not related to the progression of magnetic resonance imaging markers of cerebral small vessel disease across a nine-year follow-up, results from our study prove that high levels of physical activity in patients with cerebral small vessel disease are associated with a lower all-cause mortality and lower incidence of cerebrovascular events

European Stroke Organisation (ESO) guideline on screening for subclinical atrial fibrillation after stroke or transient ischaemic attack of undetermined origin

We aimed to provide practical recommendations for the screening of subclinical atrial fibrillation (AF) in patients with ischaemic stroke or transient ischaemic attack (TIA) of undetermined origin. These guidelines are based on the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology. Five relevant Population, Intervention, Comparator, Outcome questions were defined by a multidisciplinary module working group (MWG). Longer duration of cardiac rhythm monitoring increases the detection of subclinical AF, but the optimal monitoring length is yet to be defined. We advise longer monitoring to increase the rate of anticoagulation, but whether longer monitoring improves clinical outcomes needs to be addressed. AF detection does not differ from in- or out-patient ECG-monitoring with similar monitoring duration, so we consider it reasonable to initiate in-hospital monitoring as soon as possible and continue with outpatient monitoring for more than 48 h. Although insertable loop recorders (ILR) increase AF detection based on their longer monitoring duration, comparison with non-implantable ECG devices for similar monitoring time is lacking. We suggest the use of implantable devices, if feasible, for AF detection instead of non-implantable devices to increase the detection of subclinical AF. There is weak evidence of a useful role for blood, ECG and brain imaging biomarkers for the identification of patients at high risk of AF. In patients with patent foramen ovale, we found insufficient evidence from RCT, but prolonged cardiac monitoring in patients >55 years is advisable for subclinical AF detection. To conclude, in adult patients with ischaemic stroke or TIA of undetermined origin, we recommend longer duration of cardiac rhythm monitoring of more than 48 h and if feasible with IRL to increase the detection of subclinical AF

Event-related alpha suppression in response to facial motion

This article has been made available through the Brunel Open Access Publishing Fund.While biological motion refers to both face and body movements, little is known about the visual perception of facial motion. We therefore examined alpha wave suppression as a reduction in power is thought to reflect visual activity, in addition to attentional reorienting and memory processes. Nineteen neurologically healthy adults were tested on their ability to discriminate between successive facial motion captures. These animations exhibited both rigid and non-rigid facial motion, as well as speech expressions. The structural and surface appearance of these facial animations did not differ, thus participants decisions were based solely on differences in facial movements. Upright, orientation-inverted and luminance-inverted facial stimuli were compared. At occipital and parieto-occipital regions, upright facial motion evoked a transient increase in alpha which was then followed by a significant reduction. This finding is discussed in terms of neural efficiency, gating mechanisms and neural synchronization. Moreover, there was no difference in the amount of alpha suppression evoked by each facial stimulus at occipital regions, suggesting early visual processing remains unaffected by manipulation paradigms. However, upright facial motion evoked greater suppression at parieto-occipital sites, and did so in the shortest latency. Increased activity within this region may reflect higher attentional reorienting to natural facial motion but also involvement of areas associated with the visual control of body effectors. © 2014 Girges et al

Lower Ipsilateral Hippocampal Integrity after Ischemic Stroke in Young Adults: A Long-Term Follow-Up Study.

BACKGROUND AND PURPOSE: Memory impairment after stroke is poorly understood as stroke rarely occurs in the hippocampus. Previous studies have observed smaller ipsilateral hippocampal volumes after stroke compared with controls. Possibly, these findings on macroscopic level are not the first occurrence of structural damage and are preceded by microscopic changes that may already be associated with a worse memory function. We therefore examined the relationship between hippocampal integrity, volume, and memory performance long after first-ever ischemic stroke in young adults. METHODS: We included all consecutive first-ever ischemic stroke patients, without hippocampal strokes or recurrent stroke/TIA, aged 18-50 years, admitted to our academic hospital between 1980 and 2010. One hundred and forty-six patients underwent T1 MPRAGE, DTI scanning and completed the Rey Auditory Verbal Learning Test and were compared with 84 stroke-free controls. After manual correction of hippocampal automatic segmentation, we calculated mean hippocampal fractional anisotropy (FA) and diffusivity (MD). RESULTS: On average 10 years after ischemic stroke, lesion volume was associated with lower ipsilateral hippocampal integrity (p0.05). CONCLUSIONS: Patients with average ipsilateral hippocampal volume could already have lower ipsilateral hippocampal integrity, although at present with no attendant worse memory performance compared with patients with high hippocampal integrity. Longitudinal studies are needed to investigate whether a low hippocampal integrity after stroke might lead to exacerbated memory decline with increasing age.This study was funded by the Dutch Epilepsy Fund (grant 10–18)

Nonlinear temporal dynamics of cerebral small vessel disease: The RUN DMC study

Objective: To investigate the temporal dynamics of cerebral small vessel disease (SVD) by 3 consecutive assessments over a period of 9 years, distinguishing progression from regression. Methods: Changes in SVD markers of 276 participants of the Radboud University Nijmegen Diffusion Tensor and Magnetic Resonance Imaging Cohort (RUN DMC) cohort were assessed at 3 time points over 9 years. We assessed white matter hyperintensities (WMH) volume by semiautomatic segmentation and rated lacunes and microbleeds manually. We categorized baseline WMH severity as mild, moderate, or severe according to the modified Fazekas scale. We performed mixed-effects regression analysis including a quadratic term for increasing age. Results: Mean WMH progression over 9 years was 4.7 mL (0.54 mL/y; interquartile range 0.95–5.5 mL), 20.3% of patients had incident lacunes (2.3%/y), and 18.9% had incident microbleeds (2.2%/y). WMH volume declined in 9.4% of the participants during the first follow-up interval, but only for 1 participant (0.4%) throughout the whole follow-up. Lacunes disappeared in 3.6% and microbleeds in 5.7% of the participants. WMH progression accelerated over time: including a quadratic term for increasing age during follow-up significantly improved the model (p < 0.001). SVD progression was predominantly seen in participants with moderate to severe WMH at baseline compared to those with mild WMH (odds ratio [OR] 35.5, 95% confidence interval [CI] 15.8–80.0, p < 0.001 for WMH progression; OR 5.7, 95% CI 2.8–11.2, p < 0.001 for incident lacunes; and OR 2.9, 95% CI 1.4–5.9, p = 0.003 for incident microbleeds). Conclusions: SVD progression is nonlinear, accelerating over time, and a highly dynamic process, with progression interrupted by reduction in some, in a population that on average shows progression.A. Tuladhar is a junior staff member of the Dutch Heart Foundation (grant 2016T044). E. van Dijk received a personal fellowship from the Dutch Brain Foundation (H04-12; F2009[1]-16). L. Rutten-Jacobs is supported by a British Heart Foundation Immediate Research Fellowship (FS/15/61/31626). C. Klijn is supported by a clinical established investigator grant of the Dutch Heart Foundation (grant 2012 T077) and an Aspasia grant from The Netherlands Organisation for Health Research and Development (ZonMw grant 015.008.048). F. de Leeuw is supported by a clinical established investigator grant of the Dutch Heart Foundation (grant 2014 T060), by a VIDI innovational grant from The Netherlands Organisation for Health Research and Development (ZonMw grant 016.126.351), and the MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente

Visual search performance is predicted by both prestimulus and poststimulus electrical brain activity

© The Author(s) 2016. An individual's performance on cognitive and perceptual tasks varies considerably across time and circumstances. We investigated neural mechanisms underlying such performance variability using regression-based analyses to examine trial-by-trial relationships between response times (RTs) and different facets of electrical brain activity. Thirteen participants trained five days on a color-popout visual-search task, with EEG recorded on days one and five. The task was to find a color-popout target ellipse in a briefly presented array of ellipses and discriminate its orientation. Later within a session, better preparatory attention (reflected by less prestimulus Alpha-band oscillatory activity) and better poststimulus early visual responses (reflected by larger sensory N1 waves) correlated with faster RTs. However, N1 amplitudes decreased by half throughout each session, suggesting adoption of a more efficient search strategy within a session. Additionally, fast RTs were preceded by earlier and larger lateralized N2pc waves, reflecting faster and stronger attentional orienting to the targets. Finally, SPCN waves associated with target-orientation discrimination were smaller for fast RTs in the first but not the fifth session, suggesting optimization with practice. Collectively, these results delineate variations in visual search processes that change over an experimental session, while also pointing to cortical mechanisms underlying performance in visual search

Place- and age-responsive disaster risk reduction for Hong Kong: Collaborative Place Audit and Social Vulnerability Index for elders

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