183 research outputs found
Joining the dots: measuring the effects of a national quality improvement collaborative in ambulance services
Context: We undertook a national collaborative to improve cardiovascular care by frontline clinicians in 12 English Ambulance Services. Data were collected by clinical audit staff and submitted centrally where they were collated and analysed.
Problem: Cardiovascular disease is the commonest cause of death in the United Kingdom (UK). Acute Myocardial Infarction (AMI) causes 250,000 deaths per year and 1 in 3 heart attack victims die before reaching hospital. There are approximately 152,000 strokes per year causing more than 49,000 deaths. Early and effective treatment decreases death rates for AMI and stroke, improves long-term health and reduces future disability. National guidelines for ambulance clinicians are based on evidence for best clinical practice for AMI and stroke care by ambulance services as defined in the National Service Framework for CHD and National Stroke Strategy. Whilst ambulance clinicians were good at delivering specific aspects of care they were less effective at delivering whole bundles of care.
Assessment of problem and analysis of its causes: The process of care delivered by English ambulance services is now assessed using National Clinical Performance Indicators (nCPIs) which include measures of complete bundles of care.
The care bundle for AMI is: administration of aspirin and GTN, pain score recorded before and after treatment and administration of analgesia. The stroke care bundle consists of recording of FAST, blood glucose and blood pressure. A key project aim was to produce a sustained improvement in the national rate of care bundle delivery for AMI from 43% (range 26.2%-90.32%) to 90% and for stroke from 83.1% (range 39.4 %– 97.6%) to 90% within 2 years.
Intervention: Frontline clinicians identified barriers and facilitators to delivery of care bundles and designed and tested new processes using quality improvement (QI) methods after being trained in process mapping, root cause analysis and Plan Do Study Act cycles. The effects of interventions were tracked using annotated control charts.
Strategy for change: Quality Improvement Teams and Fellows were appointed in each service to form QI collaboratives. Collaboratives were responsible for developing and trialling localised interventions and spreading successful interventions more widely within Trusts. QI Fellows were to meet regularly to share learning.
Measurement of improvement: Statistical Process control (SPC) methods were utilised to measure the effectiveness and sustainability of interventions.
Effects of changes: With 6 months of the project left to run, the nCPIs have shown improvements in the care bundle for STEMI (mean 58.8%) and Stroke (mean 89.8%) with significant improvements in some trusts. There is evidence in some Trusts that interventions (particularly those affecting a whole Trust) are being reflected in the data although more data is needed to see whether these changes will be sustained.
Lessons learnt: Small sample sizes sometimes made local level measurement of change problematic and ways of overcoming this were developed. Barriers in service reconfiguration caused delays in starting collaboratives or trialling interventions; this highlighted the importance o f ensuring that corporate bodies clearly understood the scale and purpose of the collaboratives. Baseline and prospective data collection took longer than expected and resources for this were stretched, particularly in Trusts without electronic systems. If running similar projects on a similar scale greater clarity about roles and expectations around resourcing data collection would be needed from the outset. Annotation of the control charts proved invaluable in monitoring the effects of interventions and their sustainability.
Message for others: Annotated control charts were a powerful tool in determining whether and to what extent interventions led to improvements in care. This enabled an evidence base for spreading intervention within and beyond ambulance services on a national scale
Charge-transfer dynamics at the dye-semiconductor interface of photocathodes for solar energy applications
This article describes a comparison between the photophysical properties of two charge-transfer dyes adsorbed onto NiO via two different binding moieties. Transient spectroscopy measurements suggest that the structure of the anchoring group affects both the rate of charge recombination between the dye and NiO surface and the rate of dye regeneration by an iodide/triiodide redox couple. This is consistent with the performance of the dyes in p-type dye sensitised solar cells. A key finding was that the recombination rate differed in presence of the redox couple. This has important implications on the study of electron transfer at dye|semiconductor interfaces for solar energy applications
Investigating interfacial electron transfer in dye-sensitized NiO using vibrational spectroscopy
Understanding what influences the formation and lifetime of charge-separated states is key to developing photoelectrochemical devices. This paper describes the use of time-resolved infrared absorption spectroscopy (TRIR) to determine the structure and lifetime of the intermediates formed on photoexcitation of two organic donor–π–acceptor dyes adsorbed to the surface of NiO. The donor and π-linker of both dyes is triphenylamine and thiophene but the acceptors differ, maleonitrile (1) and bodipy (2). Despite their structural similarities, dye 1 outperforms 2 significantly in devices. Strong transient bands in the fingerprint region (1 and 2) and nitrile region (2300–2000 cm−1) for 1 enabled us to monitor the structure of the excited states in solution or adsorbed on NiO (in the absence and presence of electrolyte) and the corresponding kinetics, which are on a ps–ns timescale. The results are consistent with rapid (<1 ps) charge-transfer from NiO to the excited dye (1) to give exclusively the charge-separated state on the timescale of our measurements. Conversely, the TRIR experiments revealed that multiple species are present shortly after excitation of the bodipy chromophore in 2, which is electronically decoupled from the thiophene linker. In solution, excitation first populates the bodipy singlet excited state, followed by charge transfer from the triphenylamine to the bodipy. The presence and short lifetime (τ ≈ 30 ps) of the charge-transfer excited state when 2 is adsorbed on NiO (2|NiO) suggests that charge separation is slower and/or less efficient in 2|NiO than in 1|NiO. This is consistent with the difference in performance between the two dyes in dye-sensitized solar cells and photoelectrochemical water splitting devices. Compared to n-type materials such as TiO2, less is understood regarding electron transfer between dyes and p-type metal oxides such as NiO, but it is evident that fast charge-recombination presents a limit to the performance of photocathodes. This is also a major challenge to photocatalytic systems based on a “Z-scheme”, where the catalysis takes place on a µs–s timescale
Comparing the effects of sun exposure and vitamin D supplementation on vitamin D insufficiency, and immune and cardio-metabolic function: the Sun Exposure and Vitamin D Supplementation (SEDS) Study
BACKGROUND Adults living in the sunny Australian climate are at high risk of skin cancer, but vitamin D deficiency (defined here as a serum 25-hydroxyvitamin D (25(OH)D) concentration of less than 50 nmol/L) is also common. Vitamin D deficiency may be a risk factor for a range of diseases. However, the optimal strategies to achieve and maintain vitamin D adequacy (sun exposure, vitamin D supplementation or both), and whether sun exposure itself has benefits over and above initiating synthesis of vitamin D, remain unclear. The Sun Exposure and Vitamin D Supplementation (SEDS) Study aims to compare the effectiveness of sun exposure and vitamin D supplementation for the management of vitamin D insufficiency, and to test whether these management strategies differentially affect markers of immune and cardio-metabolic function. METHODS/DESIGN The SEDS Study is a multi-centre, randomised controlled trial of two different daily doses of vitamin D supplementation, and placebo, in conjunction with guidance on two different patterns of sun exposure. Participants recruited from across Australia are aged 18-64 years and have a recent vitamin D test result showing a serum 25(OH)D level of 40-60 nmol/L. DISCUSSION This paper discusses the rationale behind the study design, and considers the challenges but necessity of data collection within a non-institutionalised adult population, in order to address the study aims. We also discuss the challenges of participant recruitment and retention, ongoing engagement of referring medical practitioners and address issues of compliance and participant retention. TRIAL REGISTRATION Australia New Zealand Clinical Trials Registry: ACTRN12613000290796 Registered 14 March 2013
Correlation of Nav1.8 and Nav1.9 sodium channel expression with neuropathic pain in human subjects with lingual nerve neuromas
Background: Voltage-gated sodium channels Nav1.8 and Nav1.9 are expressed preferentially in small diameter sensory neurons, and are thought to play a role in the generation of ectopic activity in neuronal cell bodies and/or their axons following peripheral nerve injury. The expression of Nav1.8 and Nav1.9 has been quantified in human lingual nerves that have been previously injured inadvertently during lower third molar removal, and any correlation between the expression of these ion channels and the presence or absence of dysaesthesia investigated.
Results: Immunohistochemical processing and quantitative image analysis revealed that Nav1.8 and Nav1.9 were expressed in human lingual nerve neuromas from patients with or without symptoms of dysaesthesia. The level of Nav1.8 expression was significantly higher in patients reporting pain compared with no pain, and a significant positive correlation was observed between levels of Nav1.8 expression and VAS scores for the symptom of tingling. No significant differences were recorded in the level of expression of Nav1.9 between patients with or without pain.
Conclusions: These results demonstrate that Nav1.8 and Nav1.9 are present in human lingual nerve neuromas, with significant correlations between the level of expression of Nav1.8 and symptoms of pain. These data provide further evidence that changes in expression of Nav1.8 are important in the development and/or maintenance of nerve injury-induced pain, and suggest that Nav1.8 may be a potential therapeutic target
Absolute measurement of the tissue origins of cell-free DNA in the healthy state and following paracetamol overdose
Circularly polarized luminescence from helically chiral N,N,O,O-boron-chelated dipyrromethenes
Helically chiral N,N,O,O-boron chelated dipyrromethenes showed solution-phase circularly polarized luminescence (CPL) in the red region of the visible spectrum (λem(max) from 621 to 663 nm). The parent dipyrromethene is desymmetrised through O chelation of boron by the 3,5-ortho-phenolic substituents, inducing a helical chirality in the fluorophore. The combination of high luminescence dissymmetry factors (|glum| up to 4.7 ×10−3) and fluorescence quantum yields (ΦF up to 0.73) gave exceptionally efficient circularly polarized red emission from these simple small organic fluorophores, enabling future application in CPL-based bioimaging
Phage Orf family recombinases:conservation of activities and involvement of the central channel in DNA binding
Genetic and biochemical evidence suggests that λ Orf is a recombination mediator, promoting nucleation of either bacterial RecA or phage Redβ recombinases onto single-stranded DNA (ssDNA) bound by SSB protein. We have identified a diverse family of Orf proteins that includes representatives implicated in DNA base flipping and those fused to an HNH endonuclease domain. To confirm a functional relationship with the Orf family, a distantly-related homolog, YbcN, from Escherichia coli cryptic prophage DLP12 was purified and characterized. As with its λ relative, YbcN showed a preference for binding ssDNA over duplex. Neither Orf nor YbcN displayed a significant preference for duplex DNA containing mismatches or 1-3 nucleotide bulges. YbcN also bound E. coli SSB, although unlike Orf, it failed to associate with an SSB mutant lacking the flexible C-terminal tail involved in coordinating heterologous protein-protein interactions. Residues conserved in the Orf family that flank the central cavity in the λ Orf crystal structure were targeted for mutagenesis to help determine the mode of DNA binding. Several of these mutant proteins showed significant defects in DNA binding consistent with the central aperture being important for substrate recognition. The widespread conservation of Orf-like proteins highlights the importance of targeting SSB coated ssDNA during lambdoid phage recombination
Elimination of Schistosomiasis Transmission in Zanzibar: Baseline Findings before the Onset of a Randomized Intervention Trial.
Gaining and sustaining control of schistosomiasis and, whenever feasible, achieving local elimination are the year 2020 targets set by the World Health Organization. In Zanzibar, various institutions and stakeholders have joined forces to eliminate urogenital schistosomiasis within 5 years. We report baseline findings before the onset of a randomized intervention trial designed to assess the differential impact of community-based praziquantel administration, snail control, and behavior change interventions. In early 2012, a baseline parasitological survey was conducted in ∼20,000 people from 90 communities in Unguja and Pemba. Risk factors for schistosomiasis were assessed by administering a questionnaire to adults. In selected communities, local knowledge about schistosomiasis transmission and prevention was determined in focus group discussions and in-depths interviews. Intermediate host snails were collected and examined for shedding of cercariae. The baseline Schistosoma haematobium prevalence in school children and adults was 4.3% (range: 0-19.7%) and 2.7% (range: 0-26.5%) in Unguja, and 8.9% (range: 0-31.8%) and 5.5% (range: 0-23.4%) in Pemba, respectively. Heavy infections were detected in 15.1% and 35.6% of the positive school children in Unguja and Pemba, respectively. Males were at higher risk than females (odds ratio (OR): 1.45; 95% confidence interval (CI): 1.03-2.03). Decreasing adult age (OR: 1.04; CI: 1.02-1.06), being born in Pemba (OR: 1.48; CI: 1.02-2.13) or Tanzania (OR: 2.36; CI: 1.16-4.78), and use of freshwater (OR: 2.15; CI: 1.53-3.03) showed higher odds of infection. Community knowledge about schistosomiasis was low. Only few infected Bulinus snails were found. The relatively low S. haematobium prevalence in Zanzibar is a promising starting point for elimination. However, there is a need to improve community knowledge about disease transmission and prevention. Control measures tailored to the local context, placing particular attention to hot-spot areas, high-risk groups, and individuals, will be necessary if elimination is to be achieved
Increasing p-type dye sensitised solar cell photovoltages using polyoxometalates
Lindqvist polyoxometalate (POM) additives increase VOC in p-type DSSCs by up to 140%, yielding substantial efficiency gains for poorly matched dyes and redox mediators. For better dye/electrolyte combinations, these gains are typically outweighed by losses in JSC. Charge lifetime and transient IR measurements show that this is due to retardation of both recombination and electron transfer to the mediator, and a positive shift in the NiO valence band edge. The POMs also show their own, limited sensitizing effect
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