999 resultados para 54301-010


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The effect of varying process parameters on atmospheric plasma characteristics and properties of nanometre thick siloxane coatings is investigated in a reel-to-reel deposition process. Varying plasma operation modes were observed with increasing applied power for helium and helium/oxygen plasmas. The electrical and optical behaviour of the dielectric barrier discharge were determined from current/voltage, emission spectroscopy and time resolved light emission measurements. As applied power increased, multiple discharge events occurred, producing a uniform multi-peak pseudoglow discharge, resulting in an increase in the discharge gas temperature. The effects of different operating modes on coating oxidation and growth rates were examined by injecting hexamethyldisiloxane liquid precursor into the chamber under varying operating conditions. A quenching effect on the plasma was observed, causing a decrease in plasma input power and emission intensity. Siloxane coatings deposited in helium plasmas had a higher organic component and higher growth rates than those deposited in helium/oxygen plasmas.

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Resistance to cisplatin chemotherapy remains a major hurdle preventing effective treatment of many solid cancers. BAX and BAK are pivotal regulators of the mitochondrial apoptosis pathway, however little is known regarding their regulation in cisplatin resistant cells. Cisplatin induces DNA damage in both sensitive and resistant cells, however the latter exhibits a failure to initiate N-terminal exposure of mitochondrial BAK or mitochondrial SMAC release. Both phenotypes are highly sensitive to mitochondrial permeabilisation induced by exogenous BH3 domain peptides derived from BID, BIM, NOXA (which targets MCL-1 and A1), and there is no significant change in their prosurvival BCL2 protein expression profiles. Obatoclax, a small molecule inhibitor of pro-survival BCL-2 family proteins including MCL-1, decreases cell viability irrespective of platinum resistance status across a panel of cell lines selected for oxaliplatin resistance. In summary, selection for platinum resistance is associated with a block of mitochondrial death signalling upstream of BAX/BAK activation. Conservation of sensitivity to BH3 domain induced apoptosis can be exploited by agents such as obatoclax, which directly target the mitochondria and BCL-2 family.

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Objectives: To investigate the knowledge and views of a range of healthcare professionals (consultant paediatricians, general practitioners (GPs), community pharmacists and paediatric nurses) regarding the use of unlicensed/off-label medicines in children and the participation of children in clinical trials.

Methods: A regional study in which a survey instrument with 39 items was issued to 500 randomly selected GPs, all community pharmacists (n?=?512), 50 hospital consultants and 150 paediatric nurses in Northern Ireland.

Results: Approximately half (46.5%) of the 1,212 healthcare professionals approached responded to the questionnaire. The majority of respondents indicated their familiarity with the term unlicensed (82.9%) or off-label (58.6%) prescribing with the most frequently quoted reason for such prescribing being younger age (33.6%). Apart from community pharmacists, most respondents reported having gained their knowledge through personal experience. Even though a large percentage of respondents expressed concerns about the safety (77.8%) or efficacy (87.9%) of unlicensed/off-label prescribing in children, only 30.7% reported informing parents/guardians of these concerns on the use of such medicines in children. In addition, only 56% of respondents believed that unlicensed/off-label medicines should undergo clinical trials in children. Overall, 28.4% of respondents (20.1% of GPs, 41.4% of community pharmacists, 27.7% of paediatric nurses and 94% of consultant paediatricians) indicated their willingness to be actively involved in, and recruit their patients for paediatric clinical research.

Conclusion: The use of unlicensed and off-label medicines remains a major issue in paediatric medicine. Until such times as more licensed medicines are available for children, clear guidance should be developed to allow consistency in practice across the spectrum of healthcare professionals who are involved with such medicines in their routine practice.

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We introduce an application for the detection of aberrant behaviour within home based environments, with a focus on repetitive actions, which may be present in instance of persons suffering from dementia. Video based analysis has been used to detect the motion of a person within a given scene in addition to tracking them over the time. Detection of repetitive actions has been based on the analysis of a person's trajectory using the principles of signal correlation. Along with the ability to detect repetitive motion the developed approach also has the ability to measure the amount of activity/inactivity within the scene during a given period of time. Our results showed that the developed approach had the ability to detect all patterns in the data set examined with an average accuracy of 96.67%. This work has therefore validated the proposed concept of video based analysis for the detection of repetitive activities.

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Introduction: Rhythm organises musical events into patterns and forms, and rhythm perception in music is usually studied by using metrical tasks. Metrical structure also plays an organisational function in the phonology of language, via speech prosody, and there is evidence for rhythmic perceptual difficulties in developmental dyslexia. Here we investigate the hypothesis that the accurate perception of musical metrical structure is related to basic auditory perception of rise time, and also to phonological and literacy development in children. Methods: A battery of behavioural tasks was devised to explore relations between musical metrical perception, auditory perception of amplitude envelope structure, phonological awareness (PA) and reading in a sample of 64 typically-developing children and children with developmental dyslexia. Results: We show that individual differences in the perception of amplitude envelope rise time are linked to musical metrical sensitivity, and that musical metrical sensitivity predicts PA and reading development, accounting for over 60% of variance in reading along with age and I.Q. Even the simplest metrical task, based on a duple metrical structure, was performed significantly more poorly by the children with dyslexia. Conclusions: The accurate perception of metrical structure may be critical for phonological development and consequently for the development of literacy. Difficulties in metrical processing are associated with basic auditory rise time processing difficulties, suggesting a primary sensory impairment in developmental dyslexia in tracking the lower-frequency modulations in the speech envelope. © 2010 Elsevier.

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Objective To investigate the association between iron intake and iron status with Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC).

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The exchange of histones with protamines in sperm DNA results in sperm chromatin compaction and protection. Variations in sperm protamine expression are associated with male infertility. The aim of this study was to investigate relationships between DNA fragmentation, sperm protamines and assisted reproduction treatment. Semen and spermatozoa prepared by density-gradient centrifugation (DGC) from 73 men undergoing IVF and 24 men undergoing intracytoplasmic sperm injection (ICSI) were included in the study. Nuclear DNA fragmentation was assessed using the alkaline Comet assay and protamines were separated by acid-urea polyacrylamide gels. Sperm DNA fragmentation and protamine content (P1-DNA, P2-DNA, P1 + P2-DNA) decreased in spermatozoa after DGC. Abnormally high and low P1/P2 ratios were associated with increased sperm DNA fragmentation. Couples with idiopathic infertility had abnormally high P1/P2 ratios. Fertilization rates and embryo quality decreased as sperm DNA fragmentation or protamines increased. Sperm DNA fragmentation was lower in couples achieving pregnancies after IVF, but not after ICSI. There was no correlation between protamine content (P1-DNA, P2-DNA, P1 + P2-DNA) or P1/P2 ratios and IVF or ICSI pregnancies. Increased sperm DNA fragmentation was associated with abnormal protamination and resulted in lower fertilization rates, poorer embryo quality and reduced pregnancy rates. During late spermatogenesis, around 85% of the histones in the sperm nucleus are replaced with protamines. This process results in sperm chromatin compaction and also transcription silencing. In the human, protamines are comprised of two types: protamine-1 (P1) and protamine-2 (P2). Variations in sperm protamine expression are associated with male infertility. Similarly, sperm DNA integrity is important for male fertility. The aim of this study was to investigate relationships between DNA fragmentation, sperm protamines and assisted reproduction treatment. Semen and spermatozoa prepared by density-gradient centrifugation (DGC) from 73 men undergoing IVF and 24 men undergoing intracytoplasmic sperm injection (ICSI) were included in the study. Nuclear DNA fragmentation was assessed using the alkaline Comet assay and protamines were separated by acid-urea polyacrylamide gels. Sperm DNA fragmentation and protamine content decreased in spermatozoa after DGC. Abnormally high and low P1/P2 ratios were associated with increased sperm DNA fragmentation. Couples with idiopathic infertility had abnormally high P1/P2 ratios. Fertilization rates and embryo quality decreased as sperm DNA fragmentation or protamines increased. Sperm DNA fragmentation was lower in couples achieving pregnancies after IVF, but not after ICSI. There was no correlation between protamine content or P1/P2 ratios and IVF or ICSI pregnancies. Increased sperm DNA fragmentation was associated with abnormal protamination and resulted in lower fertilization rates, poorer embryo quality and reduced pregnancy rates.

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Objective To determine the current level of knowledge and understanding of CHD in the general public in Northern Ireland and to identify factors that are associated with higher knowledge levels. Setting Six provincial centres in Northern Ireland. Methods The data in the present study were collected using an interview administered questionnaire. 1,000 members of the general public were interviewed face-to-face. CHD knowledge was computed as a continuous variable, i.e. higher score represents better CHD knowledge. Main outcome measure CHD knowledge in the general public in Northern Ireland. Results Study respondents displayed limited knowledge and understanding of CHD. Study respondents who achieved higher CHD knowledge scores were more likely to report: exercising for 30 min three times or more per week, paying attention to their diet, being overweight, having a family history of CHD, living in a higher socioeconomic area (according to postcode) and having attended tertiary education. Respondents in the present study while recognising the role that community pharmacists had to play in helping patients manage their prescribed medicines, did not recognise the community pharmacists' role in other aspects of CHD detection or management. Conclusion The deficit in CHD knowledge could translate into inadequate preventative behaviour patterns and suboptimal clinical outcomes. If community pharmacists wish to become increasingly involved in public health delivery relating to CHD they need to develop effective and accessible services and promote these to the public who at present do not recognise this role of the community pharmacist.

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This paper describes the development of a novel metaheuristic that combines an electromagnetic-like mechanism (EM) and the great deluge algorithm (GD) for the University course timetabling problem. This well-known timetabling problem assigns lectures to specific numbers of timeslots and rooms maximizing the overall quality of the timetable while taking various constraints into account. EM is a population-based stochastic global optimization algorithm that is based on the theory of physics, simulating attraction and repulsion of sample points in moving toward optimality. GD is a local search procedure that allows worse solutions to be accepted based on some given upper boundary or ‘level’. In this paper, the dynamic force calculated from the attraction-repulsion mechanism is used as a decreasing rate to update the ‘level’ within the search process. The proposed method has been applied to a range of benchmark university course timetabling test problems from the literature. Moreover, the viability of the method has been tested by comparing its results with other reported results from the literature, demonstrating that the method is able to produce improved solutions to those currently published. We believe this is due to the combination of both approaches and the ability of the resultant algorithm to converge all solutions at every search process.

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Lateralized behaviour in the felids has been subject to little investigation. We examined the paw use of 42 domestic cats on three tasks designed to determine whether the animals performed asymmetrical motor behaviour. The influence of the cats' sex and age on their paw preferences was also explored. The distribution of the cats' paw preferences differed significantly between the three tasks. Task 1, the most complex exercise involving retrieval of a food treat from an empty jar, encouraged the most apparent display of lateralized behaviour, with all but one animal showing a strong preference to use either their left or right paw consistently. Tasks 2 (an exercise involving reaching for a toy suspended overhead) and 3 (a challenge involving reaching for a toy moving along the ground) encouraged ambilateral motor performance. Lateralized behaviour was strongly sex related. Male and female cats showed paw preferences at the level of the population, but in opposite directions. Females had a greater preference for using their right paw; males were more inclined to adopt their left paw. Feline age was unrelated to either strength or direction of preferred paw use. Overall, the findings suggest that there are two distinct populations of paw preference in the cat that cluster strongly around the animals' sex. The results also point to a relationship between lateralized behaviour and task complexity. More apparent patterns of lateralized behaviour were evident on more complex manipulatory tasks, hinting at functional brain specialization in this species. © 2009 The Association for the Study of Animal Behaviour.

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This study aimed to investigate intra- and inter-site differences in the epibiota on the European oyster Ostrea edulis of different ages and on hard substrata to assess their contribution to biodiversity. This research has shown that shells of O. edulis do show higher species diversity than non-living hard substrata and as oysters grow larger epibiotic diversity will increase. This investigation has revealed that O. edulis possesses biogenic engineering qualities and the value of O. edulis as a vehicle for increasing biodiversity should not be underestimated. Relatively few studies have examined the shell surfaces of Ostrea edulis, which, together with their associated epifauna provide a large portion of the natural hard substrata for sessile filter-feeding organisms, including oysters, in coastal and estuarine ecosystems. It can be considered a keystone species which has an influence on intertidal and subtidal community structures.