720 research outputs found

    Biocidal silver and silver/titania composite films grown by chemical vapour deposition

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    This paper describes the growth and testing of highly active biocidal films based on photocatalytically active films of TiO2, grownby thermal CVD, functionally and structurallymodified by deposition of nanostructured silver via a novel flame assisted combination CVD process. The resulting composite films are shown to be highly durable, highly photocatalytically active and are also shown to possess strong antibacterial behaviour. The deposition control, arising from the described approach, offers the potential to control the film nanostructure, which is proposed to be crucial in determining the photo and bioactivity of the combined film structure, and the transparency of the composite films. Furthermore, we show that the resultant films are active to a range of organisms, including Gram-negative and Gram-positive bacteria, and viruses. The very high-biocidal activity is above that expected from the concentrations of silver present, and this is discussed in terms of nanostructure of the titania/silver surface. These properties are especially significant when combined with the well-known durability of CVD deposited thin films, offering new opportunities for enhanced application in areas where biocidal surface functionality is sought

    Highly bioactive silver and silver/titania composite films grown by chemical vapour deposition

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    This paper describes how photocatalytically active films of TiO2, grown by thermal CVD, may be functionally and structurally modified by deposition of nano-structured silver via a novel flame assisted CVD process. The resulting composite films are shown to be highly durable, highly photocatalytically active and are also shown to possess strong antibacterial behaviour. The deposition control, arising from the described approach, offers the potential to control the film nanostructure, which is proposed to be crucial in determining the photo and bio-activity of the combined film structure, and the transparency of the composite films. Furthermore, we show that the resultant films also exhibit “self-regeneration” capability, in that they both kill bacteria present on the film surface and then photo-degrade the residues. Such a dual action significantly reducing the problems of surface deactivation due to build up of contamination. These properties are especially significant when combined with the well-known durability of CVD deposited thin films, offering new opportunities for enhanced application in areas where bioactive surface functionality is sought

    Photocatalytic antimicrobial activity of thin surface films of TiO2, CuO and TiO2 /CuO dual layers on Escherichia coli and bacteriophage T4

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    TiO2 coated surfaces are increasingly studied for their ability to inactivate microorganisms. The activity of glass coated with thin films of TiO2, CuO and hybrid CuO/TiO2 prepared by atmospheric Chemical Vapour Deposition (Ap-CVD) and TiO2 prepared by a sol-gel process was investigated using the inactivation of bacteriophage T4 as a model for inactivation of viruses. The chemical oxidising activity was also determined by measuring stearic acid oxidation. The results showed that the rate of inactivation of bacteriophage T4 increased with increasing chemical oxidising activity with the maximum rate obtained on highly active sol-gel preparations. However these were delicate and easily damaged unlike the Ap-CVD coatings. Inactivation rates were highest on CuO and CuO/TiO2 which had the lowest chemical oxidising activities. The inactivation of T4 was higher than that of Escherichia coli on low activity surfaces. The combination of photocatalysis and toxicity of copper acted synergistically to inactivate bacteriophage T4 and retained some selfcleaning activity. The presence of phosphate ions slowed inactivation but NaCl had no effect. The results show that TiO2/CuO coated surfaces are highly antiviral and may have applications in the food and healthcare industries

    Learning from contract change in primary care dentistry: a qualitative study of stakeholders in the north of England

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    The aim of this research was to explore and synthesise learning from stakeholders (NHS dentists, commissioners and patients) approximately five years on from the introduction of a new NHS dental contract in England. The case study involved a purposive sample of stakeholders associated with a former NHS Primary Care Trust (PCT) in the north of England. Semi-structured interviews were conducted with 8 commissioners of NHS dental services and 5 NHS general dental practitioners. Three focus group meetings were held with 14 NHS dental patients. All focus groups and interviews were audio recorded and transcribed verbatim. The data were analysed using a framework approach. Four themes were identified: ‘commissioners’ views of managing local NHS dental services’; ‘the risks of commissioning for patient access’; ‘costs, contract currency and commissioning constraints’; and ‘local decision-making and future priorities’. Commissioners reported that much of their time was spent managing existing contracts rather than commissioning services. Patients were unclear about the NHS dental charge bands and dentists strongly criticised the contract's target-driven approach which was centred upon them generating ‘units of dental activity’. NHS commissioners remained relatively constrained in their abilities to reallocate dental resources amongst contracts. The national focus upon practitioners achieving their units of dental activity appeared to outweigh interest in the quality of dental care provided

    Social gradient in the cost of oral pain and related dental service utilisation among South African adults

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    Background: Oral pain affects people's daily activities and quality of life. The burden of oral pain may vary across socio-economic positions. Currently, little is known about the social gradient in the cost of oral pain among South Africans. This study therefore assessed the social gradient in the cost of oral pain and the related dental service utilisation pattern among South African adults. Methods: Data were obtained from a nationally representative cross-sectional survey of South African adults ?16 year-old (n = 2651) as part of the South African Social Attitudes Survey conducted by the South African Human Sciences Research Council. The survey included demographic data, individual-level socio-economic position (SEP), self-reported oral health status, past six months' oral pain experience and cost. The area-level SEP was obtained from the 2010 General Household Survey (n = 25,653 households) and the 2010/2011Quarterly Labour Force Survey conducted in South Africa. The composite indices used for individual-level SEP (? = 0.76) and area-level SEP (? = 0. 88) were divided into tertiles. Data analysis was done using t-tests and ANOVA. Significance was set at p < 0.05. Results: The prevalence of oral pain among the adult South Africans was 19.4 % (95 % CI = 17.2-21.9). The most commonly reported form of oral pain was 'toothache' (78.9 %). The majority of the wealthiest participants sought care from private dental clinics (64.7 %), or from public dental clinics (19.7 %), while the poorest tended to visit a public dental clinic (45 %) or nurse/general medical practitioner (17.4 %). In the poorest areas, 21 % responded to pain by 'doing nothing'. The individual expenditure for oral pain showed a social gradient from an average of ZAR61.44 spent by those of lowest SEP to ZAR433.83 by the wealthiest (national average ZAR170.92). Average time lost from school/work was two days over the six-month period, but days lost was highest for those living in middle class neighbourhoods (3.41), while those from the richest neighbourhood had lost significantly fewer days from oral pain (0.64). Conclusions: There is a significant social gradient in the burden of oral pain. Improved access to dental care, possibly through carefully planned universal National Health Insurance (NHI), may reduce oral health disparities in South Africa.Scopus 201

    Alcohol affects neuronal substrates of response inhibition but not of perceptual processing of stimuli signalling a stop response

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    Alcohol impairs inhibitory control, including the ability to terminate an initiated action. While there is increasing knowledge about neural mechanisms involved in response inhibition, the level at which alcohol impairs such mechanisms remains poorly understood. Thirty-nine healthy social drinkers received either 0.4g/kg or 0.8g/kg of alcohol, or placebo, and performed two variants of a Visual Stop-signal task during acquisition of functional magnetic resonance imaging (fMRI) data. The two task variants differed only in their instructions: in the classic variant (VSST), participants inhibited their response to a “Go-stimulus” when it was followed by a “Stop-stimulus”. In the control variant (VSST_C), participants responded to the “Go-stimulus” even if it was followed by a “Stop-stimulus”. Comparison of successful Stop-trials (Sstop)>Go, and unsuccessful Stop-trials (Ustop)>Sstop between the three beverage groups enabled the identification of alcohol effects on functional neural circuits supporting inhibitory behaviour and error processing. Alcohol impaired inhibitory control as measured by the Stop-signal reaction time, but did not affect other aspects of VSST performance, nor performance on the VSST_C. The low alcohol dose evoked changes in neural activity within prefrontal, temporal, occipital and motor cortices. The high alcohol dose evoked changes in activity in areas affected by the low dose but importantly induced changes in activity within subcortical centres including the globus pallidus and thalamus. Alcohol did not affect neural correlates of perceptual processing of infrequent cues, as revealed by conjunction analyses of VSST and VSST_C tasks. Alcohol ingestion compromises the inhibitory control of action by modulating cortical regions supporting attentional, sensorimotor and action-planning processes. At higher doses the impact of alcohol also extends to affect subcortical nodes of fronto-basal ganglia- thalamo-cortical motor circuits. In contrast, alcohol appears to have little impact on the early visual processing of infrequent perceptual cues. These observations clarify clinically-important effects of alcohol on behaviour

    The future of pediatric dentistry education and curricula : A Chilean perspective

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    Publisher Copyright: © 2016 The Author(s). Copyright: Copyright 2016 Elsevier B.V., All rights reserved.Background: A meeting was organised to consolidate a network of researchers and academics from Australia, Brazil, Chile, the UK and the USA, relating to Early Childhood Caries (ECC) and Dental Trauma (DT). As part of this meeting, a dedicated session was held on the future of paediatric dental education and curricula. Twenty-four paediatric dentistry (PD) academics, representing eight Chilean dental schools, and three international specialists (from Brazil and Latvia) participated in group discussions facilitated by five members of the ECC/DT International Collaborative Network. Data were collected from group discussions which followed themes developed as guides to identify key issues associated with paediatric dentistry education, training and research. Discussion: Participants discussed current PD dental curricula in Chile, experiences in educating new cohorts of oral health care providers, and the outcomes of existing efforts in education and research in PD. They also, identified challenges, opportunities and areas in need of further development. Summary: This paper provides an introspective analysis of the education and training of PD in Chile; describes the input provided by participants into pediatric dentistry education and curricula; and sets out some key priorities for action with suggested directions to best prepare the future dental workforce to maximise oral health outcomes for children. Immediate priorities for action in paediatric dentistry in Chile were proposed.publishersversionPeer reviewe

    Caries prevalence and tooth loss in Hungarian adult population: results of a national survey

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    <p>Abstract</p> <p>Background</p> <p>Oral health is basicly important for the well-being of people. Thus, it is strongly suggested to organize epidemiological surveys in order to gain representative data on oral condition of the given population. The purpose of the cross-sectional study was to determine the results on tooth loss and caries prevalence of Hungarian adults in different age groups.</p> <p>Methods</p> <p>Altogether 4606 persons (2923 women, 1683 men) participated in the study who were classified into different age groups: 19 [less than or equal to], 20–24, 35–44, 45–64, 65–74, [greater than or equal to]75 year olds. Probands were selected randomly from the population attending the compulsory lung screening examinations. The participants were examined by calibrated dentists, according to the WHO (1997) criteria. In order to produce representative data, the chosen localities for these examinations covered the capital, the largest towns, the villages, and case weights were used for the statistical evaluation.</p> <p>Results</p> <p>The mean values of DMF-T were found between 11.79±5.68 and 21.90±7.61 These values were significantly higher in women compared to men (p < 0.05). In all age groups the values of M were the highest. Except for the women in the groups of 35–44 and 45–64 year olds, these values showed an increasing tendency both in women and men by age (from 5.50±6.49, and 4.70±4.08 to 21.52±9.07 and 18.41±8.89 respectively). The values of D components reached the highest values in 45–64 year olds (4.54±2.12 and 4.22±2.81, by gender, respectively), then in the older age groups there was a high reduction in these values (in 65–74 year olds: 2.72±1.88 and 1.36±2.48; in 75 or more than 75 year olds: 1.05±1.41 and 1.03±1.76 by gender, respectively). The ratio of D and F values was the highest in the age group of 65–74 year olds (2.12), the lowest ratio could be calculated in 20–34 year olds (0.65).</p> <p>Data showed some decrease in caries experience in 35–44 years of age between 2000 and 2004. The prevalence of persons with 21 or more teeth had been increased from 65.6% to 73.1%. This positive tendency has not been occured in prevalence of edentulousness in this age group: the prevalence of edentulous persons changed from 1.4 to 1.9%. In 65–74 year olds the level of edentulousness became lower, from 25.9 to 14.8% and the prevalence of persons with 21 or more teeth is higher (22.6%) than it was in 2000 (13.0%).</p> <p>Conclusion</p> <p>Present data from Hungary show some slight decrease in caries experience between 35–44 years of age, although this positive tendency has not been occured in prevalence of edentulousness in this age group. A positive tendency could be experienced in the group of 65–74 year olds in edentulousness and in number of teeth, but further efforts are needed to reach a better situation.</p
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