46 research outputs found

    In situ optical measurement of charge transport dynamics in organic photovoltaics.

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    We present a novel experimental approach which allows extraction of both spatial and temporal information on charge dynamics in organic solar cells. Using the wavelength dependence of the photonic structure in these devices, we monitor the change in spatial overlap between the photogenerated hole distribution and the optical probe profile as a function of time. In a model system we find evidence for a buildup of the photogenerated hole population close to the hole-extracting electrode on a nanosecond time scale and show that this can limit charge transport through space-charge effects under operating conditions.This work was supported by the EPSRC [Grant number EP/ G060738/1].This is the author accepted manuscript. The final published version is available at http://pubs.acs.org/doi/abs/10.1021/nl503687u

    The nucleoporin ALADIN regulates Aurora A localization to ensure robust mitotic spindle formation

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    The formation of the mitotic spindle is a complex process that requires massive cellular reorganization. Regulation by mitotic kinases controls this entire process. One of these mitotic controllers is Aurora A kinase, which is itself highly regulated. In this study, we show that the nuclear pore protein ALADIN is a novel spatial regulator of Aurora A. Without ALADIN, Aurora A spreads from centrosomes onto spindle microtubules, which affects the distribution of a subset of microtubule regulators and slows spindle assembly and chromosome alignment. ALADIN interacts with inactive Aurora A and is recruited to the spindle pole after Aurora A inhibition. Of interest, mutations in ALADIN cause triple A syndrome. We find that some of the mitotic phenotypes that we observe after ALADIN depletion also occur in cells from triple A syndrome patients, which raises the possibility that mitotic errors may underlie part of the etiology of this syndrome

    Origin of Secretin Receptor Precedes the Advent of Tetrapoda: Evidence on the Separated Origins of Secretin and Orexin

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    At present, secretin and its receptor have only been identified in mammals, and the origin of this ligand-receptor pair in early vertebrates is unclear. In addition, the elusive similarities of secretin and orexin in terms of both structures and functions suggest a common ancestral origin early in the vertebrate lineage. In this article, with the cloning and functional characterization of secretin receptors from lungfish and X. laevis as well as frog (X. laevis and Rana rugulosa) secretins, we provide evidence that the secretin ligand-receptor pair has already diverged and become highly specific by the emergence of tetrapods. The secretin receptor-like sequence cloned from lungfish indicates that the secretin receptor was descended from a VPAC-like receptor prior the advent of sarcopterygians. To clarify the controversial relationship of secretin and orexin, orexin type-2 receptor was cloned from X. laevis. We demonstrated that, in frog, secretin and orexin could activate their mutual receptors, indicating their coordinated complementary role in mediating physiological processes in non-mammalian vertebrates. However, among the peptides in the secretin/glucagon superfamily, secretin was found to be the only peptide that could activate the orexin receptor. We therefore hypothesize that secretin and orexin are of different ancestral origins early in the vertebrate lineage

    Experiences of a community pharmacy service to support adherence and self-management in chronic heart failure

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    Background: Heart failure (HF) is common, disabling and deadly. Patients with HF often have poor self-care and medicines non-adherence, which contributes to poor outcomes. Community pharmacy based cognitive services have the potential to help, but we do not know how patients view community-pharmacist-led services for patients with HF. Objective: We aimed to explore and portray in detail, the perspectives of patients receiving, and pharmacists delivering an enhanced, pay for performance community pharmacy HF service. Setting: Community pharmacies and community-based patients in Greater Glasgow and Clyde, Scotland. Methods Focus groups with pharmacists and semi-structured interviews with individual patients by telephone. Cross sectional thematic analysis of qualitative data used Normalization Process Theory to understand and describe patient's reports. Main outcome measure: Experiences of receiving and delivering an enhanced HF service. Results: Pharmacists voiced their confidence in delivering the service and highlighted valued aspects including the structured consultation and repeated contacts with patients enabling the opportunity to improve self care and medicines adherence. Discussing co-morbidities other than HF was difficult and persuading patients to modify behaviour was challenging. Patients were comfortable discussing symptoms and medicines with pharmacists; they identified pharmacists as fulfilling roles that were needed but not currently addressed. Patients reported the service helped them to enact HF medicines and HF self care management strategies. Conclusion: Both patients receiving and pharmacists delivering a cognitive HF service felt that it addressed a shortfall in current care. There may be a clearly defined role for pharmacists in supporting patients to address the burden of understanding and managing their condition and treatment, leading to better self management and medicines adherence. This study may inform the development of strategies or policies to improve the process of care for patients with HF and has implications for the development of other extended role services

    The Knockout of Secretin in Cerebellar Purkinje Cells Impairs Mouse Motor Coordination and Motor Learning

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    Secretin (SCT) was first considered to be a gut hormone regulating gastrointestinal functions when discovered. Recently, however, central actions of SCT have drawn intense research interest and are supported by the broad distribution of SCT in specific neuronal populations and by in vivo physiological studies regarding its role in water homeostasis and food intake. The direct action of SCT on a central neuron was first discovered in cerebellar Purkinje cells in which SCT from cerebellar Purkinje cells was found to potentiate GABAergic inhibitory transmission from presynaptic basket cells. Because Purkinje neurons have a major role in motor coordination and learning functions, we hypothesize a behavioral modulatory function for SCT. In this study, we successfully generated a mouse model in which the SCT gene was deleted specifically in Purkinje cells. This mouse line was tested together with SCT knockout and SCT receptor knockout mice in a full battery of behavioral tasks. We found that the knockout of SCT in Purkinje neurons did not affect general motor ability or the anxiety level in open field tests. However, knockout mice did exhibit impairments in neuromuscular strength, motor coordination, and motor learning abilities, as shown by wire hanging, vertical climbing, and rotarod tests. In addition, SCT knockout in Purkinje cells possibly led to the delayed development of motor neurons, as supported by the later occurrence of key neural reflexes. In summary, our data suggest a role in motor coordination and motor learning for SCT expressed in cerebellar Purkinje cells
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