18,184 research outputs found

    Bioactivity of toothpaste containing bioactive glass in remineralizing media: effect of fluoride release from the enzymatic cleavage of monofluorophosphate

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    Objectives. The aim was to introduce a new methodology to characterize toothpaste containing bioactive glass and to evaluate the effect of release of fluoride ions, by cleaving monofluorophosphate (MFP), on the mineral forming ability of Sensodyne Repair & Protect (SRP). which contains NovaMinTM (bioactive glass, 45S5 composition). Methods. SRP, NovaMin particles, and placebo paste (PLA) which did not contain NovaMin, were immersed into a remineralization media (RS), which mimics the ionic strength of human saliva, for 3 days with different concentrations of alkaline phosphatase (ALP): 0, 25 and 75 U.L−1. Ion concentration profiles and pH were monitored by ICPOES and F− ion selective electrode. Remaining solids were collected by freeze-drying and their surfaces analysed. Results. Hydroxyapatite (HA) formed on the surface of BG alone (after 1 h) and in toothpaste (after 2 h), whereas PLA did not induce any precipitation. ALP cleaved MFP at different rates depending on the enzyme concentration. Increasing the concentration of ALP from 0 and 75 U.L−1 reduced the time of HA formation from 2 h to 24 h. However, the presence of fluoride induced the precipitation of fluorapatite. No evidence of fluorite (CaF2) was observed. The apatite formation ability of toothpaste can be assessed using the presented method

    Investigation of phase separation within the generalized Lin-Taylor model for a binary liquid mixture of large hexagonal and small triangular particles

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    The generalized Lin-Taylor model defined on the hexagonal lattice is used to investigate the phase separation in an asymmetric binary liquid mixture consisting of large A (hexagons) and small B (triangles) particles. By considering interaction energies between A-A and A-B pairs of particles that occupy nearest-neighbour cells of the hexagonal lattice, we have derived an exact solution for the considered model system having established a mapping correspondence with the two-dimensional Ising model on its dual triangular lattice. Altogether, six different types of coexistence curves including those with reentrant miscibility regions (i.e. closed-loop coexistence curves) were found in dependence on the relative strength between both coupling constants.Comment: 8 pages, 4 figures, presented at 7th Liblice conference on the Statistical Mechanics of Liquids to be held in Lednice on June 11-16, 200

    A randomized controlled trial of a specific reminiscence approach to promote the well-being of nursing home residents with dementia

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    Background: To date, no firm conclusions can be reached regarding the effectiveness of reminiscence for dementia. Researchers have emphasized that there is an urgent need for more systematic research in the area. Objective and Method: A single-blinded, parallel-groups (one intervention, one comparison, and one no-intervention group) randomized controlled trial (RCT) was adopted to investigate whether a specific reminiscence program leads to higher levels of psychosocial well-being in nursing home residents with dementia. The intervention adopted a life-story approach, while the comparison group provided friendly discussions to control for any changes in outcome as a result of social contacts and attention. The Social Engagement Scale (SES) and Well-being/Ill-being Scale (WIB) were the outcome measures used. The outcomes of the groups were examined with reference to the baseline (T0), immediately (T1), and six weeks (T2) after intervention. The final sample had 101 subjects (control group: n=30; comparison group: n=35; intervention group: n=36). Using multivariate analysis with repeated measures, no significant differences in outcome were found between groups at either T1 or T2. Wilcoxon signed rank tests were performed for each group comparing outcomes between T1 and T0, T2 and T1, and T2 and T0. Significant differences were observed in the intervention group when comparing T1 and T0 WIB (p=.014), but not for the other groups. Conclusion: Although the intervention did not lead to significant differences between the three groups over time, there was a significant improvement in psychosocial well-being for the intervention group.published_or_final_versio

    Phase equilibria in the Fe-Mo-Ti ternary system at 1000 °C

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    An isothermal section of the Fe-Mo-Ti ternary system at 1000 °C has been constructed using data acquired from a series of seven alloys. The limit of solubility of Fe in the continuous A2 phase field between Ti and Mo has been determined, as have the extents to which Mo may be accommodated in the B2 TiFe phase, and Ti in the D85_5 Fe7_7Mo6_6 phase. The B2, D85_5 and C14 Fe2_2 (Ti, Mo) intermetallics were found to have limited tolerance for non-stoichiometric compositions. The positions of the A2 + B2 + C14 and A2 + C14 + D85_5 three-phase fields were determined, along with the extents of the A2 + B2, A2 + D85_5, A2 + C14, C14 + B2 and C14 + D85_5 two-phase fields. No ternary phases were observed in any of the alloys studied.This work was support by the Rolls-Royce/EPSRC Strategic Partnership under EP/H022309/1, EP/H500375/1 and EP/M005607/1.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.ijrmhm.2016.07.00

    Development of Marine Protected Areas (MPAs) in Vietnam from a coevolutionary governance perspective: Challenges of unholy alliances between the state, businesses and NGOs

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    Marine Protected Areas (MPAs) are widely recognised as a management framework for achieving biodiversity conservation and sustainable ocean uses. Although the attention to improving the governance of MPAs as a priority for achieving effective MPAs has been escalated, debates concerning MPA governance are inspired mainly by the bottom-up governance approach and its focus on horizontal and vertical linkages as a means of resolving conflicts, with the assumption that the state should only take a passive role. As the debates on the best MPA governance model continue, the progress of spatially expanding the global MPA network remains slow and has created many paper parks. Through a coevolutionary governance lens, this paper aims to empirically examine the development of MPAs in Vietnam and reflect on the national realities of achieving global biodiversity targets. Our findings emphasise that governance frameworks adopted for Vietnamese MPAs are typically characterised by a significant decentralisation of responsibilities to province-/district-level governments but with a lack of conditions and accountability attached to such responsibilities and of related oversight from the central government. Consequences include rent-seeking and clientelism opportunities for local authorities, elite capture of MPA benefits, and diminishing trust and stewardship among local communities. Our study suggests that, in the face of increasing overfishing and corporate interests nurtured by the unholy alliances between the state, businesses and NGOs, effective and equitable MPAs critically rely on synergies among different governance approaches, which are case-specific, along with sufficient political will and oversight from the state

    Pregnancy has a minimal impact on the acute transcriptional signature to vaccination.

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    Vaccination in pregnancy is an effective tool to protect both the mother and infant; vaccines against influenza, pertussis and tetanus are currently recommended. A number of vaccines with a specific indication for use in pregnancy are in development, with the specific aim of providing passive humoral immunity to the newborn child against pathogens responsible for morbidity and mortality in young infants. However, the current understanding about the immune response to vaccination in pregnancy is incomplete. We analysed the effect of pregnancy on early transcriptional responses to vaccination. This type of systems vaccinology approach identifies genes and pathways that are altered in response to vaccination and can be used to understand both the acute inflammation in response to the vaccine and to predict immunogenicity. Pregnant women and mice were immunised with Boostrix-IPV, a multivalent vaccine, which contains three pertussis antigens. Blood was collected from women before and after vaccination and RNA extracted for analysis by microarray. While there were baseline differences between pregnant and non-pregnant women, vaccination induced characteristic patterns of gene expression, with upregulation in interferon response and innate immunity gene modules, independent of pregnancy. We saw similar patterns of responses in both women and mice, supporting the use of mice for preclinical screening of novel maternal vaccines. Using a systems vaccinology approach in pregnancy demonstrated that pregnancy does not affect the initial response to vaccination and that studies in non-pregnant women can provide information about vaccine immunogenicity and potentially safety

    An XMM and Chandra view of massive clusters of galaxies to z=1

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    The X-ray properties of a sample of high redshift (z>0.6), massive clusters observed with XMM-Newton and Chandra are described, including two exceptional systems. One, at z=0.89, has an X-ray temperature of T=11.5 (+1.1, -0.9) keV (the highest temperature of any cluster known at z>0.6), an estimated mass of (1.4+/-0.2)x10^15 solar masses and appears relaxed. The other, at z=0.83, has at least three sub-clumps, probably in the process of merging, and may also show signs of faint filamentary structure at large radii,observed in X-rays. In general there is a mix of X-ray morphologies, from those clusters which appear relaxed and containing little substructure to some highly non-virialized and probably merging systems. The X-ray gas metallicities and gas mass fractions of the relaxed systems are similar to those of low redshift clusters of the same temperature, suggesting that the gas was in place, and containing its metals, by z=0.8. The evolution of the mass-temperature relation may be consistent with no evolution or with the ``late formation'' assumption. The effect of point source contamination in the ROSAT survey from which these clusters were selected is estimated, and the implications for the ROSAT X-ray luminosity function discussed.Comment: 9 pages, in Carnegie Observatories Astrophysics Series, Vol. 3: Clusters of Galaxies: Probes of Cosmological Structure and Galaxy Evolution, ed. J. S. Mulchaey, A. Dressler, and A. Oemler. See http://www.ociw.edu/ociw/symposia/series/symposium3/proceedings.html for a full-resolution versio
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