Angiogenesis in old-aged subjects after ischemic stroke : a cautionary note for investigators

Angiogenesis represents a form of neovascularisation of exceptional importance in numerous pathological conditions including stroke. In this context it is directly related to neuroregeneration which is seen in close proximity. However, numerous experimental data have been drawn from studies that have ignored the age criterion. This is extremely important as angiogenesis is different in young versus old subjects. Extrapolating data obtained from studies performed in young subjects or "in vitro" to old-age patients could lead to inexact conclusions since the dynamics of angiogenesis is age-dependent.The current review covers the key features of brain senescence including morphological and functional changes related to the brain parenchyma, its vascular network and blood flow which could possibly influence the process of angiogenesis. This is followed by a description of post-stroke angiogenesis and its relationship to neuroregeneration and its modulation by vascular endothelial growth factor (VEGF) and insulin-like growth factor 1 (IGF 1), the most important factors active in old brain after ischemic injury.

Poly(2,5-bis(2-octyldodecyl)-3,6-di(furan-2-yl)-2,5-dihydro-pyrrolo[3,4-c] pyrrole-1,4-dione-co-thieno[3,2-b]thiophene): A high performance polymer semiconductor for both organic thin film transistors and organic photovoltaics

A new diketopyrrolopyrrole (DPP)-containing donor-acceptor polymer, poly(2,5-bis(2-octyldodecyl)-3,6-di(furan-2-yl)-2,5-dihydro-pyrrolo[3,4-c] pyrrole-1,4-dione-co-thieno[3,2-b]thiophene) (PDBF-co-TT), is synthesized and studied as a semiconductor in organic thin film transistors (OTFTs) and organic photovoltaics (OPVs). High hole mobility of up to 0.53 cm 2 V -1 s -1 in bottom-gate, top-contact OTFT devices is achieved owing to the ordered polymer chain packing and favoured chain orientation, strong intermolecular interactions, as well as uniform film morphology of PDBF-co-TT. The optimum band gap of 1.39 eV and high hole mobility make this polymer a promising donor semiconductor for the solar cell application. When paired with a fullerene acceptor, PC 71BM, the resulting OPV devices show a high power conversion efficiency of up to 4.38% under simulated standard AM1.5 solar illumination.

3,6-Di(furan-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione and bithiophene copolymer with rather disordered chain orientation showing high mobility in organic thin film transistors

Pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione or diketopyrrolopyrrole (DPP) is a useful electron-withdrawing fused aromatic moiety for the preparation of donor-acceptor polymers as active semiconductors for organic electronics. This study uses a DPP-furan-containing building block, 3,6-di(furan-2-yl)pyrrolo[3,4- c]pyrrole-1,4(2H,5H)-dione (DBF), to couple with a 2,2′-bithiophene unit, forming a new donor-acceptor copolymer, PDBFBT. Compared to its structural analogue, 3,6-di(thiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione (DBT), DBF is found to cause blue shifts of the absorption spectra both in solution and in thin films and a slight reduction of the highest occupied molecular orbital (HOMO) energy level of the resulting PDBFBT. Despite the fact that its thin films are less crystalline and have a rather disordered chain orientation in the crystalline domains, PDBFBT shows very high hole mobility up to 1.54 cm 2 V-1 s-1 in bottom-gate, top-contact organic thin film transistors.

Solution processable poly(2,5-dialkyl-2,5-dihydro-3,6-di-2-thienyl- pyrrolo[3,4-c]pyrrole-1,4-dione) for ambipolar organic thin film transistors

Solution processable diketopyrrolopyrrole (DPP)-bithiophene polymers (PDBT) with long branched alkyl side chains on the DPP unit are synthesized. These polymers have favourable highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels for the injection and transport of both holes and electrons. Organic thin film transistors (OTFTs) using these polymers as semiconductors and gold as source/drain electrodes show typical ambipolar characteristics with very well balanced high hole and electron mobilities (μ h = 0.024 cm 2 V -1 s -1 and μ e = 0.056 cm 2 V -1 s -1). These simple and high-performing polymers are promising materials for ambipolar organic thin film transistors for low-cost CMOS-like logic circuits.

The pathophysiology of ischaemic stroke : considerations for emergency department advanced practice nursing

Stroke is the fourth most important cause of death in Singapore. Its major predisposing factors include hypertension, type 2 diabetes mellitus and hyperlipidaemia; all modifiable diseases if treated early. However, with Singapore’s elderly population, the risk and rates of stroke are ever increasing. The nature of a stroke can be categorised as eitherh aemorrhagic or ischaemic; the former caused by arterial rupture, the latter by arterial blockage; both can be devastating in their prognosis and outcome. This paper will discuss the pathophysiology of ischaemic stroke while identifying some of the key features of ischaemia on different areas of the brain relative to the artery that feeds them. Thoughts for Emergency Department advanced practice nursing will also be discussed.

Reliability in the Parameterization of the Functional Reach Test in Elderly Stroke Patients: A Pilot Study

BACKGROUND: Postural instability is one of the major complications found in stroke survivors. Parameterising the functional reach test (FRT) could be useful in clinical practice and basic research. OBJECTIVES: To analyse the reliability, sensitivity, and specificity in the FRT parameterisation using inertial sensors for recording kinematic variables in patients who have suffered a stroke. DESIGN: Cross-sectional study. While performing FRT, two inertial sensors were placed on the patient's back (lumbar and trunk). PARTICIPANTS: Five subjects over 65 who suffer from a stroke. MEASUREMENTS: FRT measures, lumbosacral/thoracic maximum angular displacement, maximum time of lumbosacral/thoracic angular displacement, time return initial position, and total time. Speed and acceleration of the movements were calculated indirectly. RESULTS: FRT measure is  12.75±2.06 cm. Intrasubject reliability values range from 0.829 (time to return initial position (lumbar sensor)) to 0.891 (lumbosacral maximum angular displacement). Intersubject reliability values range from 0.821 (time to return initial position (lumbar sensor)) to 0.883 (lumbosacral maximum angular displacement). FRT's reliability was 0.987 (0.983-0.992) and 0.983 (0.979-0.989) intersubject and intrasubject, respectively. CONCLUSION: The main conclusion could be that the inertial sensors are a tool with excellent reliability and validity in the parameterization of the FRT in people who have had a stroke.

A statistical model for combustion resonance from a DI diesel engine with applications

Introduced in this paper is a Bayesian model for isolating the resonant frequency from combustion chamber resonance. The model shown in this paper focused on characterising the initial rise in the resonant frequency to investigate the rise of in-cylinder bulk temperature associated with combustion. By resolving the model parameters, it is possible to determine: the start of pre-mixed combustion, the start of diffusion combustion, the initial resonant frequency, the resonant frequency as a function of crank angle, the in-cylinder bulk temperature as a function of crank angle and the trapped mass as a function of crank angle. The Bayesian method allows for individual cycles to be examined without cycle-averaging|allowing inter-cycle variability studies. Results are shown for a turbo-charged, common-rail compression ignition engine run at 2000 rpm and full load.

5,7-di-N-acetyl-acinetaminic acid: A novel non-2-ulosonic acid found in the capsule of an Acinetobacter baumannii isolate

An Acinetobacter baumannii global clone 1 (GC1) isolate was found to carry a novel capsule biosynthesis gene cluster, designated KL12. KL12 contains genes predicted to be involved in the synthesis of simple sugars, as well as ones for N-acetyl-l-fucosamine (l-FucpNAc) and N-acetyl-d-fucosamine (d-FucpNAc). It also contains a module of 10 genes, 6 of which are required for 5,7-di-N-acetyl-legionaminic acid synthesis. Analysis of the composition of the capsule revealed the presence of N-acetyl-d-galactosamine, l-FucpNAc and d-FucpNAc, confirming the role of fnlABC and fnr/gdr genes in the synthesis of l-FucpNAc and d-FucpNAc, respectively. A non-2-ulosonic acid, shown to be 5,7-diacetamido-3,5,7,9-tetradeoxy-l-glycero-l-altro-non-2-ulosonic acid, was also detected. This sugar has not previously been recovered from biological source, and was designated 5,7-di-N-acetyl-acinetaminic acid (Aci5Ac7Ac). Proteins encoded by novel genes, named aciABCD, were predicted to be involved in the conversion of 5,7-di-N-acetyl-legionaminic acid to Aci5Ac7Ac. A pathway for 5,7-di-N-acetyl-8-epilegionaminic acid biosynthesis was also proposed. In available A. baumannii genomes, genes for the synthesis of 5,7-di-N-acetyl-acinetaminic acid were only detected in two closely related capsule gene clusters, KL12 and KL13, which differ only in the wzy gene. KL12 and KL13 are carried by isolates belonging to clinically important clonal groups, GC1, GC2 and ST25. Genes for the synthesis of N-acyl derivatives of legionaminic acid were also found in 10 further A. baumannii capsule gene clusters, and three carried additional genes for production of 5,7-di-N-acetyl-8-epilegionaminic acid.

Comparison of kinematic variables obtained by inertial sensors among stroke survivors and healthy older adults in the Functional Reach Test: cross-sectional study

Background Balance dysfunction is one of the most common problems in people who suffer stroke. To parameterize functional tests standardized by inertial sensors have been promoted in applied medicine. The aim of this study was to compare the kinematic variables of the Functional Reach Test (FRT) obtained by two inertial sensors placed on the trunk and lumbar region between stroke survivors (SS) and healthy older adults (HOA) and to analyze the reliability of the kinematic measurements obtained. Methods Cross-sectional study. Five SS and five HOA over 65. A descriptive analysis of the average range as well as all kinematic variables recorded was developed. The intrasubject and intersubject reliability of the measured variables was directly calculated. Results In the same intervals, the angular displacement was greater in the HOA group; however, they were completed at similar times for both groups, and HOA conducted the test at a higher speed and greater acceleration in each of the intervals. The SS values were higher than HOA values in the maximum and minimum acceleration in the trunk and in the lumbar region. Conclusions The SS show less functional reach, a narrower, slower and less accelerated movement during the FRT execution, but with higher peaks of acceleration and speed when they are compared with HOA.

Advance care planning in stroke: Influence of time on engagement in the process

Purpose Individuals who experience stroke have a higher likelihood of subsequent stroke events, making it imperative to plan for future medical care. In the event of a further serious health event, engaging in the process of advanced care planning (ACP) can help family members and health care professionals (HCPs) make medical decisions for individuals who have lost the capacity to do so. Few studies have explored the views and experiences of patients with stroke about discussing their wishes and preferences for future medical events, and the extent to which stroke HCPs engage in conversations around planning for such events. In this study, we sought to understand how the process of ACP unfolded between HCPs and patients post-stroke. Patients and methods Using grounded theory (GT) methodology, we engaged in direct observation of HCP and patient interactions on an acute stroke unit and two stroke rehabilitation units. Using semi-structured interviews, 14 patients and four HCPs were interviewed directly about the ACP process. Results We found that open and continual ACP conversations were not taking place, patients experienced an apparent lack of urgency to engage in ACP, and HCPs were uncomfortable initiating ACP conversations due to the sensitive nature of the topic. Conclusion In this study, we identified lack of engagement in ACP post-stroke, attributable to patient and HCP factors. This encourages us to look further into the process of ACP in order to develop open communication between the patient with stroke, their families, and stroke HCPs.

Randomized clinical trial of the timing it right stroke family support program: Research protocol

Background Family caregivers provide invaluable support to stroke survivors during their recovery, rehabilitation, and community re-integration. Unfortunately, it is not standard clinical practice to prepare and support caregivers in this role and, as a result, many experience stress and poor health that can compromise stroke survivor recovery and threaten the sustainability of keeping the stroke survivor at home. We developed the Timing it Right Stroke Family Support Program (TIRSFSP) to guide the timing of delivering specific types of education and support to meet caregivers' evolving needs. The objective of this multi-site randomized controlled trial is to determine if delivering the TIRSFSP across the stroke care continuum improves caregivers' sense of being supported and emotional well-being. Methods/design Our multi-site single-blinded randomized controlled trial will recruit 300 family caregivers of stroke survivors from urban and rural acute care hospitals. After completing a baseline assessment, participants will be randomly allocated to one of three groups: 1) TIRSFSP guided by a stroke support person (health care professional with stroke care experience), delivered in-person during acute care and by telephone for approximately the first six to 12 months post-stroke; 2) caregiver self-directed TIRSFSP with an initial introduction to the program by a stroke support person, or; 3) standard care receiving the educational resource "Let's Talk about Stroke" prepared by the Heart and Stroke Foundation. Participants will complete three follow-up quantitative assessments 3, 6, and 12-months post-stroke. These include assessments of depression, social support, psychological well-being, stroke knowledge, mastery (sense of control over life), caregiving assistance provided, caregiving impact on everyday life, and indicators of stroke severity and disability. Qualitative methods will also be used to obtain information about caregivers' experiences with the education and support received and the impact on caregivers' perception of being supported and emotional well-being. Discussion This research will determine if the TIRSFSP benefits family caregivers by improving their perception of being supported and emotional well-being. If proven effective, it could be recommended as a model of stroke family education and support that meets the Canadian Stroke Best Practice Guideline recommendation for providing timely education and support to families through transitions.

The World Stroke Organization and nursing [Guest Editorial]

The field of neuroscience nursing and, in particular, nursing people with stroke has evolved significantly over the past two decades. Nurses working with people who have had a stroke and their families are called upon to use advanced assessment skills, apply nursing diagnoses across the whole continuum of care, and identify and implement a wide range of interventions. Indeed, in a recent Canadian study on the implementation of stroke best practices, nurses were identified as playing a leading role in many aspects of stroke care and recovery. As the volume of research evidence across disciplines mounts, nurses are challenged to “keep up on the latest”...

Report: The Canadian Best Practices Educational Toolkits: Translating evidence-based stroke recommendations into practical implementation resources

The Canadian Best Practice Recommendations for Stroke Care are intended to reduce variations in stroke care and facilitate closure of the gap between evidence and practice (Lindsay et al., 2010). The publication of best practice recommendations is only the beginning of this process. The guidelines themselves are not sufficient to change practice and increase consistency in care. Therefore, a key objective of the Canadian Stroke Network (CSN) Best Practices Working Group (BPWG) is to encourage and facilitate ongoing professional development and training for health care professionals providing stroke care. This is addressed through a multi-factorial approach to the creation and dissemination of inter-professional implementation tools and resources. The resources developed by CSN span pre-professional education, ongoing professional development, patient education and may be used to inform systems change. With a focus on knowledge translation, several inter-professional point-of-care tools have been developed by the CSN in collaboration with numerous professional organizations and expert volunteers. These resources are used to facilitate awareness, understanding and applications of evidence-based care across stroke care settings. Similar resources are also developed specifically for stroke patients, their families and informal caregivers, and the general public. With each update of the Canadian Best Practice Recommendations for Stroke Care, the BPWG and topic-specific writing groups propose priority areas for ongoing resource development. In 2010, two of these major educational initiatives were undertaken and recently completed—one to support continuing education for health care professionals regarding secondary stroke prevention and the other to educate families, informal caregivers and the public about pediatric stroke. This paper presents an overview of these two resources, and we encourage health care professionals to integrate these into their personal learning plans and tool kits for patients.