Hybrid halide perovskite neutron detectors.

Interest in fast and easy detection of high-energy radiation (x-, γ-rays and neutrons) is closely related to numerous practical applications ranging from biomedicine and industry to homeland security issues. In this regard, crystals of hybrid halide perovskite have proven to be excellent detectors of x- and γ-rays, offering exceptionally high sensitivities in parallel to the ease of design and handling. Here, we demonstrate that by assembling a methylammonium lead tri-bromide perovskite single crystal (CH3NH3PbBr3 SC) with a Gadolinium (Gd) foil, one can very efficiently detect a flux of thermal neutrons. The neutrons absorbed by the Gd foil turn into γ-rays, which photo-generate charge carriers in the CH3NH3PbBr3 SC. The induced photo-carriers contribute to the electric current, which can easily be measured, providing information on the radiation intensity of thermal neutrons. The dependence on the beam size, bias voltage and the converting distance is investigated. To ensure stable and efficient charge extraction, the perovskite SCs were equipped with carbon electrodes. Furthermore, other types of conversion layers were also tested, including borated polyethylene sheets as well as Gd grains and Gd2O3 pellets directly engulfed into the SCs. Monte Carlo N-Particle (MCNP) radiation transport code calculations quantitatively confirmed the detection mechanism herein proposed.

Visuospatial working memory interference with recollections of trauma.

OBJECTIVES: Laboratory research using a working memory framework has shown modality-specific reductions in image vividness and emotionality when concurrent tasks are performed while maintaining the image in consciousness. We extended this research to trauma images in a clinical population awaiting treatment for post-traumatic stress symptoms. DESIGN: A within-subjects design was used, with each participant completing an imagery task under three concurrent task conditions: side-to-side eye-movements, counting, and exposure only (no concurrent task). METHODS: Eighteen participants selected three images each, the images being those that were the most distressing from participants' trauma memories and most likely to intrude involuntarily. Participants gave baseline ratings of the vividness and emotionality of each of their trauma images. Each image was assigned to a condition. Each condition comprised 8 trials in which participants recollected the appropriate image for 8 s while performing eye-movements, counting or no concurrent task, and then rated its vividness and emotionality. Follow-up ratings were obtained by telephone 1 week later. RESULTS: The eye-movement task reduced vividness and emotionality of the trauma images relative to the counting task and exposure only, but did so only during the imagery period and not at follow-up. The images were predominantly visual. CONCLUSIONS: Concurrent tasks matched to the modality of trauma images may provide a useful treatment aid for temporarily dampening emotional responses to recollections of trauma.

A qualitative study of stroke patients' and carers' perceptions of the stroke family support organizer service.

OBJECTIVE: To investigate stroke patients' and carers' perceptions of the family support organizer (FSO) service in order to highlight its value for potential purchasers and to help shed light on findings from randomized controlled trials. DESIGN AND SUBJECTS: Twenty semi-structured interviews were undertaken with a subsample of stroke patients and their primary informal carers after completion of nine-month outcome assessments as part of a randomized controlled trial. SETTING: Community stroke services in North Nottinghamshire, UK. RESULTS: Interviewees who received the service reported that the presence of an FSO was valuable in many respects, including helping to claim benefits, as a source of information on stroke, and providing continuity between stroke services. Emotional support was only described by a few. Interviewees who did not receive the service described feelings of isolation and being let down by other stroke services after discharge. They also reported problems accessing information. Help needed to address the practical problems after stroke was commonly reported. For those who did not receive the FSO service, access to support appeared to be found through other channels. CONCLUSION: The FSO service appeared to be an information service. In order to evaluate community stroke services, a mixture of qualitative and quantitative outcome measures are necessary.

Evaluation of a stroke family support organiser: a randomized controlled trial.

BACKGROUND AND PURPOSE: There is inconclusive evidence of the effectiveness of the Stroke Family Support Organiser (FSO) service. We report the results from a randomized controlled trial of the service. METHODS: Stroke patients admitted to hospital and their informal caregivers were randomly allocated to receive the FSO service (n=126) or standard care (n=124). Outcome assessments were undertaken 4 and 9 months after recruitment with the General Health Questionnaire 12, Carer Strain Index, Barthel Index, Extended Activities of Daily Living scale, and a specially designed questionnaire to determine knowledge of stroke and satisfaction with services. RESULTS: There were no significant differences between groups in patients' mood and independence in personal or instrumental activities of daily living or caregivers' mood, strain, or independence. Patients in the intervention group were significantly more knowledgeable about whom to contact for stroke information, reducing the risk of stroke, practical help, community services, and emotional support. Patients in the intervention group were also significantly more satisfied with the stroke information received. Caregivers in the intervention group were significantly more knowledgeable about whom to contact for information on stroke, reducing the risk of stroke, community services, and emotional support. Caregivers in the intervention group were also significantly more satisfied with stroke information. CONCLUSIONS: The FSO service had no significant effect on mood, independence in activities of daily living, or reduction in caregiver strain, but it did increase knowledge of stroke and satisfaction with that knowledge. The results may not be representative of all FSO services, and the sample was small relative to the heterogeneity of the participants. However, results suggest that the policies and training procedures of FSOs need to be evaluated to ensure that a cost-effective service is being provided to stroke patients and their caregivers.