28 resultados para 030404 Cheminformatics and Quantitative Structure-Activity Relationships


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Aims To examine the importance of family management, family structure and father–adolescent relationships on early adolescent alcohol use.

Design Cross-sectional data was collected across 30 randomly selected Australian communities stratified to represent a range of socio-economic and regional variation.

Setting Data were collected during school time from adolescents attending a broad range of schools.

Participants The sample consisted of a combined 8256 students (aged 10–14 years).

Measurements Students completed a web-based survey as part of the Healthy Neighbourhoods project.

Findings Family management—which included practices such as parental monitoring and family rules about alcohol use—had the strongest and most consistent relationship with alcohol use in early adolescence. Adolescents reporting higher family management were less likely to have drunk alcohol in their life-time, less likely to drink alcohol in the preceding 30 days and less likely to have had an alcohol binge. Adolescents reporting emotionally close relationships with their fathers were less likely to have drunk alcohol in their life-time and less likely to have had an alcohol binge in the preceding fortnight.

Conclusions Findings indicate that family management practices may contribute to alcohol abstinence in adolescents. Furthermore, emotionally close father–adolescent relationships may also foster abstinence; however, fathers’ drinking behaviours need to be considered.

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The addition of various kinds of plasticizers can enhance the conductivity of polymer electrolyte systems, in some cases by many orders of magnitude. The plasticizer may be a low molecular weight solvent, or be a low molecular weight polymer. As the plasticizer concentration increases there is an inevitable deterioration in material properties. In this work we have investigated the effect of plasticizer on the conductivity, thermal properties and matrial properties of a number of systems including urethane cross-linked polyethers and polyacrylates. In some of the systems, in particular the polyether electrolytes, the plasticizer acts to enhance conduction by acting as a cosolvent for the salt as well as increasing chain flexibility. Its efficacy is dependent on its structure and characteristics as a solvent. Although Tg is lowered in a close to linear fashion with increasing plasticizer content and thereby conductivity increased rapidly, the elastic modulus changes more slowly. This reflects the coupling of conduction to the local mobility of the molecular units of the combined solvent system and the relative decoupling of the mobility and glass transition from the material properties. In these systems the latter are a function mainly of the longer range structure of the polymer network. The changes in conductivity and materials properties are interpreted in terms of a configurational entropy model of the solution.

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This paper investigates the effect of both the mixing technique and heating rate during cure on the dispersion of montmorillonite (MMT) clay in an epoxy resin. The combination of sonication and using a 10. °C/min heating rate during cure was found to facilitate the dispersion of nanoclay in epoxy resin. These processing conditions provided a synergistic effect, making it possible for polymer chains to penetrate in-between clay galleries and detach platelets from their agglomerates. As the degree of dispersion was enhanced, the flexural modulus and strength properties were found to decrease by 15% and 40%, respectively. This is thought to be due to individual platelets fracturing in the nanocomposite. Complementary techniques including X-ray diffraction (XRD), small angle X-ray scattering (SAXS), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), transmission electron microscopy (TEM) and optical microscopy were essential to fully characterise localised and spatial regions of the clay morphologies.

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Four new triphenyltin(IV) complexes of composition Ph3SnLH (where LH = 2-/4-[(E)-2-(aryl)-1-diazenyl]benzoate) (1–4) were synthesized and characterized by spectroscopic (1H, 13C and 119Sn NMR, IR, 119Sn Mössbauer) techniques in combination with elemental analysis. The 119Sn NMR spectroscopic data indicate a tetrahedral coordination geometry in non-coordinating solvents. The crystal structures of three complexes, Ph3SnL1H (1), Ph3SnL3H (3), Ph3SnL4H (4), were determined. All display an essentially tetrahedral geometry with angles ranging from 93.50(8) to 124.5(2)°; 119Sn Mössbauer spectral data support this assignment. The cytotoxicity studies were performed with complexes 1–4, along with a previously reported complex (5) in vitro across a panel of human tumor cell lines viz., A498, EVSA-T, H226, IGROV, M19 MEL, MCF-7 and WIDR. The screening results were compared with the results from other related triphenyltin(IV) complexes (6–7) and tributyltin(IV) complexes (8–11) having 2-/4-[(E)-2-(aryl)-1-diazenyl]benzoates framework. In general, the complexes exhibit stronger cytotoxic activity. The results obtained for 1–3 are also comparable to those of its o-analogs i.e. 4–7, except 5, but the advantage is the former set of complexes demonstrated two folds more cytotoxic activity for the cell line MCF-7 with ID50 values in the range 41–53 ng/ml. Undoubtedly, the cytotoxic results of complexes 1–3 are far superior to CDDP, 5-FU and ETO, and related tributyltin(IV) complexes 8–11. The quantitative structure-activity relationship (QSAR) studies for the cytotoxicity of triphenyltin(IV) complexes 1–7 and tributyltin(IV) complexes 8–11 is also discussed against a panel of human tumor cell lines.

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Significant world events often cause the behavioral convergence of the expression of shared sentiment. This paper examines the use of the blogosphere as a framework to study user psychological behaviors, using their sentiment responses as a form of ‘sensor’ to infer real-world events of importance automatically. We formulate a novel temporal sentiment index function using quantitative measure of the valence value of bearing words in blog posts in which the set of affective bearing words is inspired from psychological research in emotion structure. The annual local minimum and maximum of the proposed sentiment signal function are utilized to extract significant events of the year and corresponding blog posts are further analyzed using topic modeling tools to understand their content. The paper then examines the correlation of topics discovered in relation to world news events reported by the mainstream news service provider, Cable News Network, and by using the Google search engine. Next, aiming at understanding sentiment at a finer granularity over time, we propose a stochastic burst detection model, extended from the work of Kleinberg, to work incrementally with stream data. The proposed model is then used to extract sentimental bursts occurring within a specific mood label (for example, a burst of observing ‘shocked’). The blog posts at those time indices are analyzed to extract topics, and these are compared to real-world news events. Our comprehensive set of experiments conducted on a large-scale set of 12 million posts from Livejournal shows that the proposed sentiment index function coincides well with significant world events while bursts in sentiment allow us to locate finer-grain external world events.

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It is well-documented that auent people, on average, have higher subjective wellbeing (SWB) than do poor people. is phenomenon has been explained using SWB homeostasis theory. However, a more precise understanding of the dierences in personal experience that lead to homeostatic failure remains to be documented. We sought such understanding through qualitative interviews and a quantitative examination of SWB domains. Twenty auent people and 20 people dependent on social welfare completed an interview and the Personal Wellbeing Index. As expected, the two groups diered signicantly in SWB. Moreover, the poor group reported a preponderance of negative life experiences while the auent group concentrated on the positive events in their lives. Most telling was the nding that both the qualitative and quantitative methods identied the area of ‘relationships’ as representing the greatest degree of divergence between the two groups. is life domain is especially relevant in the maintenance of normative levels of SWB.

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Microscopy encompasses a wide variety of forms and scales. So too does the array of simulation techniques developed that correlate to and build upon microstructural information. Nevertheless, a true nexus between microscopy and atomistic simulations is lacking. Atom probe has emerged as a potential means of achieving this goal. Atom probe generates three-dimensional atomistic images in a format almost identical to many atomistic simulations. However, this data is imperfect, preventing input into computational algorithms to predict material properties. Here we describe a methodology to overcome these limitations, based on a hybrid data format, blending atom probe and predictive Monte Carlo simulations. We create atomically complete and lattice-bound models of material specimens. This hybrid data can then be used as direct input into density functional theory simulations to calculate local energetics and elastic properties. This research demonstrates the role that atom probe combined with theoretical approaches can play in modern materials engineering.

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The transition from active employment to retirement is a potentially critical period for promoting maintenance or development of recreational physical activity in older age. Park proximity and quality might be important correlates of recreational physical activity in this age group. However, research on park-physical activity relationships among mid-older aged adults is limited and inconclusive. Furthermore, while knowledge of individual moderators of park-physical activity relationships is crucial for tailoring interventions, this knowledge is also limited. We investigated relationships between perceived park proximity, park quality and recreational physical activity among mid-older aged adults. Additionally, we examined the potential moderating effects of gender, education level, retirement status, functional limitations and area of residence on these relationships.

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Background: Regular participation in physical activity (PA) can help reduce the risk of overweight/obesity. Parental practices related to PA are modifiable determinants of preschoolers' PA that are still not well understood, especially in non-Western cultures. This qualitative explorative study aimed to identify parental practices encouraging or discouraging PA in Hong Kong preschoolers. Methods: Nominal Group Technique (NGT) sessions (n = 45; 6 to 9/group), complemented by a focus group (n = 6) and individual interviews (n = 12), were conducted with primary caregivers (mainly parents) of Hong Kong preschoolers to investigate what parents do to encourage (4 groups) and discourage (2 groups) PA in children. The groups were stratified by low and high neighborhood socioeconomic status. Results: Participants generated 21 and 16 items describing practices encouraging and discouraging preschoolers' PA, respectively. Parental provision of instrumental, motivational, and conditional support were thought to encourage child's PA, while parental safety concerns, focus on academic achievement, lack of time and resources, and promotion of sedentary behaviors were thought to discourage child's PA. Conclusions: Several parental practices that were deemed to encourage or discourage Hong Kong preschoolers' PA were identified. These can assist with development of a culturally sensitive scale of PA parenting practices and inform future quantitative research.

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Broad antifungal structure-activity relationships governing epoxy-endoperoxides 2 and 3 and their parent endoperoxides 1 are reported. Their inhibitory activity against Candida albicans in conjunction with hemolytic activity and/or growth inhibition of cultured mammalian cells are reported. This information provided guidance for the further development of endoperoxide and epoxy-endoperoxides as topical antifungal agents.

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 Aim: The purpose of this study was to create predictive species distribution models (SDMs) for temperate reef-associated fish species densities and fish assemblage diversity and richness to aid in marine conservation and spatial planning. Location: California, USA. Methods: Using generalized additive models, we associated fish species densities and assemblage characteristics with seafloor structure, giant kelp biomass and wave climate and used these associations to predict the distribution and assemblage structure across the study area. We tested the accuracy of these predicted extrapolations using an independent data set. The SDMs were also used to estimate larger scale abundances to compare with other estimates of species abundance (uniform density extrapolation over rocky reef and density extrapolations taking into account variations in geomorphic structure). Results: The SDMs successfully modelled the species-habitat relationships of seven rocky reef-associated fish species and showed that species' densities differed in their relationships with environmental variables. The predictive accuracy of the SDMs ranged from 0.26 to 0.60 (Pearson's r correlation between observed and predicted density values). The SDMs created for the fish assemblage-level variables had higher prediction accuracies with Pearson's r values of 0.61 for diversity and 0.71 for richness. The comparisons of the different methods for extrapolating species densities over a single marine protected area varied greatly in their abundance estimates with the uniform extrapolation (density values extrapolated evenly over the rocky reef) always estimating much greater abundances. The other two methods, which took into account variation in the geomorphic structure of the reef, provided much lower abundance estimates. Main conclusions: Species distribution models that combine geomorphic, oceanographic and biogenic habitat variables can reliably predict spatial patterns of species density and assemblage attributes of temperate reef fishes at spatial scales of 50 m. Thus, SDMs show great promise for informing spatial and ecosystem-based approaches to conservation and fisheries management. © 2015 John Wiley

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In an ongoing effort to rationally design new antimicrobials, 47 new 1,2-dioxines have been synthesised. Broad antifungal structure-activity relationships governing aromatically substituted epoxy-1,2-dioxines 2 and 3 and their parent 1,2-dioxines 1 were assessed primarily against the pathogenic yeast, Candida albicans, with haemolytic activity of selected examples also reported.

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BACKGROUND: Fundamental movement skill (FMS) competence is positively associated with physical activity (PA). However, levels of both FMS and PA are lower than expected. Current reviews of interventions to improve FMS and PA have shown that many school-based programs have achieved positive outcomes, yet the maintenance of these interventions is variable. Teachers play a central role in the success and longevity of school-based interventions. Despite the importance of teacher engagement, research into the nature and quality of teacher training in school-based PA and FMS interventions has received little attention.

OBJECTIVE: The aim of this systematic review was to investigate the type and quantity of teacher training in school-based physical education PA and/or FMS interventions, and to identify what role teacher training had on the intervention outcome.

METHODS: A systematic search of eight electronic databases was conducted. Publication date restrictions were not implemented in any database, and the last search was performed on 1 March 2015. School physical education-based interventions facilitated by a school teacher, and that included a quantitative assessment of FMS competence and/or PA levels were included in the review.

RESULTS: The search identified 39 articles. Eleven of the studies measured FMS, 25 studies measured PA and three measured both FMS and PA. Nine of the studies did not report on any aspect of the teacher training conducted. Of the 30 studies that reported on teacher training, 25 reported statistically significant intervention results for FMS and/or PA. It appears that teacher training programs: are ≥ 1 day; provide comprehensive subject and pedagogy content; are framed by a theory or model; provide follow-up or ongoing support; and measure teacher satisfaction of the training, are more effective at improving student outcomes in FMS and/or PA. However, the provision of information regarding the characteristics of the teacher training was largely inadequate. Therefore, it was difficult to ascertain which teacher training characteristics were most important in relation to intervention effectiveness.

CONCLUSION: It is clear that whilst teachers are capable of making substantial improvements in student outcomes in PA and FMS, the findings of this review suggest the teacher training component of school-based PA and/or FMS interventions is not only under-reported but is under-studied, and, perhaps as a result, the value of teacher training is not widely understood. What remains unclear, due to poor reporting, is what role teacher training is having on these outcomes.