305 research outputs found

    Photoactive antagonists for the GABAA receptor

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    GABAA receptors are an integral part of regulating neuronal transmission. Through the action of their endogenous agonist, γ-aminobutyric acid, they control most neuronal signal inhibition. GABAA receptors constantly move through the membrane, readily adapting to different stimuli, aided by transient interactions with scaffolding proteins. This thesis attempts to design and synthesise small, novel chemical tracking devices in order to gain insight into the driving forces of GABAA receptor diffusion. To this aim, photoaffinity labelled probe 1, based on a GABAA receptor antagonist gabazine, was synthesised. A benzophenone photoaffinity label was prepared, and installed onto a pyridazinyl-phenol core. A Sonogashira reaction, to install a carboxylic acid handle for the biotinylated linker, initially proved unsuccessful until the replacement of aryl bromide with an aryl iodide (Figure 1). Biotinylated probe 1 was associated with a quantum dot coated in streptavidin, and placed in live neurons. Real-time recording of the quantum dot trajectories show receptors moving in synaptic and extrasynaptic sites. Figure 1: Photoaffinity probe 1 for tracking GABAA receptors in cells. This thesis also describes a modular synthetic strategy to build additional chemical tools. A “clickable” alkyne gabazine fragment 2 was synthesised and underwent copper catalysed alkyne-azide couplings to give probes 3 and 4. These covalently bind to the receptor through an acrylamide electrophilic moiety, and cleavage of the directing gabazine fragment after UV light leaves a silently-tagged receptor. Further generations of these probes could be used to track unblocked, native receptors in order to compare the effects of antagonism on receptor movement (Figure 2). Figure 2: Photocleavable affinity antagonists 3 and 4 In addition, this thesis discusses a novel photoswitchable antagonist, azo-gabazine 5, which uses the cis-trans photoisomerisation of azobenzene to tune its potency under different wavelengths of light. It is synthesised and used to confer a photoswitching ability onto a native neuronal GABAA receptors in a biological setting (Figure 3). Figure 3: Development of a photoswitchable antagonist to the GABAA receptor, azo-gabazine 5

    Azogabazine; a photochromic antagonist of the GABAA receptor

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    The design and synthesis of azogabazine is described, which represents a highly potent (IC50 = 23 nM) photoswitchable antagonist of the GABAA receptor. An azologization strategy is adopted, in which a benzyl phenyl ether in a high affinity gabazine analogue is replaced by an azobenzene, with resultant retention of antagonist potency. We show that cycling from blue to UV light, switching between trans and cis isomeric forms, leads to photochemically controlled antagonism of the GABA ion channel

    Delivering effective care through mobile apps:Findings from a multi-stakeholder design science approach

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    In this paper, we use a design science approach to develop a mobile app for lung cancer patients that facilitates their interactions with their clinicians, manages and reports on their health status, and provides them access to medical information/education. This paper contributes to the information systems literature by demonstrating the value of design science research to co-create solutions that advance health care outcomes through technological innovations. The design process engaged a diverse cast of experts and methods, such as a survey of oncologists and cancer patients, a workshop, roundtables and interviews with leading patient and clinician association representatives and focus groups, including two panels each of clinicians and cancer patients. Our approach also develops actionable knowledge that is grounded in evidence from the field, including design guidelines that recapitulate what we learned from the design-testing-redesign cycles of our artefact

    Investigating and learning lessons from early experiences of implementing ePrescribing systems into NHS hospitals:a questionnaire study

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    Background: ePrescribing systems have significant potential to improve the safety and efficiency of healthcare, but they need to be carefully selected and implemented to maximise benefits. Implementations in English hospitals are in the early stages and there is a lack of standards guiding the procurement, functional specifications, and expected benefits. We sought to provide an updated overview of the current picture in relation to implementation of ePrescribing systems, explore existing strategies, and identify early lessons learned.Methods: a descriptive questionnaire-based study, which included closed and free text questions and involved both quantitative and qualitative analysis of the data generated.Results: we obtained responses from 85 of 108 NHS staff (78.7% response rate). At least 6% (n = 10) of the 168 English NHS Trusts have already implemented ePrescribing systems, 2% (n = 4) have no plans of implementing, and 34% (n = 55) are planning to implement with intended rapid implementation timelines driven by high expectations surrounding improved safety and efficiency of care. The majority are unclear as to which system to choose, but integration with existing systems and sophisticated decision support functionality are important decisive factors. Participants highlighted the need for increased guidance in relation to implementation strategy, system choice and standards, as well as the need for top-level management support to adequately resource the project. Although some early benefits were reported by hospitals that had already implemented, the hoped for benefits relating to improved efficiency and cost-savings remain elusive due to a lack of system maturity.Conclusions: whilst few have begun implementation, there is considerable interest in ePrescribing systems with ambitious timelines amongst those hospitals that are planning implementations. In order to ensure maximum chances of realising benefits, there is a need for increased guidance in relation to implementation strategy, system choice and standards, as well as increased financial resources to fund local activitie

    The second data release of the INT Photometric Ha Survey of the Northern Galactic Plane (IPHAS DR2)

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    The INT/WFC Photometric Hα Survey of the Northern Galactic Plane (IPHAS) is a 1800 deg2 imaging survey covering Galactic latitudes |b| < 5° and longitudes ℓ = 30°–215° in the r, i, and Hα filters using the Wide Field Camera (WFC) on the 2.5-m Isaac Newton Telescope (INT) in La Palma. We present the first quality-controlled and globally calibrated source catalogue derived from the survey, providing single-epoch photometry for 219 million unique sources across 92 per cent of the footprint. The observations were carried out between 2003 and 2012 at a median seeing of 1.1 arcsec (sampled at 0.33 arcsec pixel−1) and to a mean 5σ depth of 21.2 (r), 20.0 (i), and 20.3 (Hα) in the Vega magnitude system. We explain the data reduction and quality control procedures, describe and test the global re-calibration, and detail the construction of the new catalogue. We show that the new calibration is accurate to 0.03 mag (root mean square) and recommend a series of quality criteria to select accurate data from the catalogue. Finally, we demonstrate the ability of the catalogue's unique (r − Hα, r − i) diagram to (i) characterize stellar populations and extinction regimes towards different Galactic sightlines and (ii) select and quantify Hα emission-line objects. IPHAS is the first survey to offer comprehensive CCD photometry of point sources across the Galactic plane at visible wavelengths, providing the much-needed counterpart to recent infrared surveys

    ‘Can you recommend any good STI apps?’ A review of content, accuracy and comprehensiveness of current mobile medical applications for STIs and related genital infections

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    Objective Seeking sexual health information online is common, and provision of mobile medical applications (apps) for STIs is increasing. Young people, inherently at higher risk of STIs, are avid users of technology, and apps could be appealing sources of information. We undertook a comprehensive review of content and accuracy of apps for people seeking information about STIs. Methods Search of Google Play and iTunes stores using general and specific search terms for apps regarding STIs and genital infections (except HIV), testing, diagnosis and management, 10 September 2014 to 16 September 2014. We assessed eligible apps against (1) 19 modified Health on The Net (HON) Foundation principles; and (2) comprehensiveness and accuracy of information on STIs/genital infections, and their diagnosis and management, compared with corresponding National Health Service STI information webpage content. Results 144/6642 apps were eligible. 57 were excluded after downloading. 87 were analysed. Only 29% of apps met ≥6 HON criteria. Content was highly variable: 34/87 (39%) covered one or two infections; 40 (46%) covered multiple STIs; 5 (6%) focused on accessing STI testing. 13 (15%) were fully, 46 (53%) mostly and 28 (32%) partially accurate. 25 (29%) contained ≥1 piece of potentially harmful information. Apps available on both iOS and Android were more accurate than single-platform apps. Only one app provided fully accurate and comprehensive information on chlamydia. Conclusions Marked variation in content, quality and accuracy of available apps combined with the nearly one-third containing potentially harmful information risks undermining potential benefits of an e-Health approach to sexual health and well-being.The Electronic Self-Testing Instruments for Sexually Transmitted Infection (eSTI2) Consortium is funded under the UKCRC Translational Infection Research (TIR) Initiative supported by the Medical Research Council (Grant Number G0901608) with contributions to the Grant from the Biotechnology and Biological Sciences Research Council, the National Institute for Health Research on behalf of the Department of Health, the Chief Scientist Office of the Scottish Government Health Directorates and the Wellcome Trust

    A trial protocol for the effectiveness of digital interventions for preventing depression in adolescents : The Future Proofing Study

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    Background: Depression frequently first emerges during adolescence, and one in five young people will experience an episode of depression by the age of 18 years. Despite advances in treatment, there has been limited progress in addressing the burden at a population level. Accordingly, there has been growing interest in prevention approaches as an additional pathway to address depression. Depression can be prevented using evidence-based psychological programmes. However, barriers to implementing and accessing these programmes remain, typically reflecting a requirement for delivery by clinical experts and high associated delivery costs. Digital technologies, specifically smartphones, are now considered a key strategy to overcome the barriers inhibiting access to mental health programmes. The Future Proofing Study is a large-scale school-based trial investigating whether cognitive behaviour therapies (CBT) delivered by smartphone application can prevent depression. Methods: A randomised controlled trial targeting up to 10,000 Year 8 Australian secondary school students will be conducted. In Stage I, schools will be randomised at the cluster level either to receive the CBT intervention app (SPARX) or to a non-active control group comparator. The primary outcome will be symptoms of depression, and secondary outcomes include psychological distress, anxiety and insomnia. At the 12-month follow-up, participants in the intervention arm with elevated depressive symptoms will participate in an individual-level randomised controlled trial (Stage II) and be randomised to receive a second CBT app which targets sleep difficulties (Sleep Ninja) or a control condition. Assessments will occur post intervention (both trial stages) and at 6, 12, 24, 36, 48 and 60 months post baseline. Primary analyses will use an intention-to-treat approach and compare changes in symptoms from baseline to follow-up relative to the control group using mixed-effect models. Discussion: This is the first trial testing the effectiveness of smartphone apps delivered to school students to prevent depression at scale. Results from this trial will provide much-needed insight into the feasibility of this approach. They stand to inform policy and commission decisions concerning if and how such programmes should be deployed in school-based settings in Australia and beyond

    The Future Proofing Study: Design, methods and baseline characteristics of a prospective cohort study of the mental health of Australian adolescents

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    Objectives: The Future Proofing Study (FPS) was established to examine factors associated with the onset and course of mental health conditions during adolescence. This paper describes the design, methods, and baseline characteristics of the FPS cohort. Methods: The FPS is an Australian school-based prospective cohort study with an embedded cluster-randomized controlled trial examining the effects of digital prevention programs on mental health. Data sources include self-report questionnaires, cognitive functioning, linkage to health and education records, and smartphone sensor data. Participants are assessed annually for 5 years. Results: The baseline cohort (N = 6388, M = 13.9 years) is broadly representative of the Australian adolescent population. The clinical profile of participants is comparable to other population estimates. Overall, 15.1% of the cohort met the clinical threshold for depression, 18.6% for anxiety, 31.6% for psychological distress, and 4.9% for suicidal ideation. These rates were significantly higher in adolescents who identified as female, gender diverse, sexuality diverse, or Aboriginal and/or Torres Strait Islander (all ps < 0.05). Conclusions: This paper provides current and comprehensive data about the status of adolescent mental health in Australia. The FPS cohort is expected to provide significant insights into the risk, protective, and mediating factors associated with development of mental health conditions during adolescence
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