456 research outputs found

    Oral Health - A Neglected Aspect of Subjective Well-Being in Later Life

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    OBJECTIVES: This study examined whether oral health is a neglected aspect of subjective well-being (SWB) among older adults. The key research question was whether deterioration in oral health among dentate older adults living in England was associated with decreases in SWB, using measures of eudemonic, evaluative, and affective dimensions of well-being. METHODS: This secondary analysis used data from the third (2006-2007) and fifth (2010-2011) waves of respondents aged 50 and older from the English Longitudinal Study of Ageing (ELSA). We fitted multivariable regression models to examine the effects of changes in oral impacts on daily life and edentulism (complete tooth loss) on SWB (quality of life, life satisfaction, and depressive symptomatology). RESULTS: A worsening in both oral health measures was associated with an increase in depressive symptoms even after adjusting for time-varying confounders including declining health, activities of daily living, and reduced social support. Becoming edentate was also associated with decreases in quality of life and life satisfaction. DISCUSSION: A deterioration in oral health and oral health-related quality of life increases the risk of depressive symptoms among older adults and highlights the importance of oral health as a determinant of subjective well-being in later life

    Oral health-related quality of life and loneliness among older adults

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    Loneliness is a serious concern in aging populations. The key risk factors include poor health, depression, poor material circumstances, and low social participation and social support. Oral disease and tooth loss have a significant negative impact on the quality of life and well-being of older adults. However, there is a lack of studies relating oral health to loneliness. This study investigated the association between oral health-related quality of life (through the use of the oral impact on daily performances—OIDP—measure) and loneliness amongst older adults living in England. Data from respondents aged 50 and older from the third (2006–2007) and fifth (2010–2011) waves of the English Longitudinal Study of Ageing were analyzed. In the cross-sectional logistic regression model that adjusted for socio-demographic, socio-economic, health, and psychosocial factors, the odds of loneliness were 1.48 (1.16–1.88; p < 0.01) higher amongst those who reported at least one oral impact compared to those with no oral impact. Similarly, in the fully adjusted longitudinal model, respondents who reported an incident oral impact were 1.56 times (1.09–2.25; p < 0.05) more likely to become lonely. The association between oral health-related quality of life and loneliness was attenuated after adjusting for depressive symptoms, low social participation, and social support. Oral health-related quality of life was identified as an independent risk factor for loneliness amongst older adults. Maintaining good oral health in older age may be a protective factor against loneliness

    A novel mode of chromosomal evolution peculiar to filamentous Ascomycete fungi

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    Background: Gene loss, inversions, translocations, and other chromosomal rearrangements vary among species, resulting in different rates of structural genome evolution. Major chromosomal rearrangements are rare in most eukaryotes, giving large regions with the same genes in the same order and orientation across species. These regions of macrosynteny have been very useful for locating homologous genes in different species and to guide the assembly of genome sequences. Previous analyses in the fungi have indicated that macrosynteny is rare; instead, comparisons across species show no synteny or only microsyntenic regions encompassing usually five or fewer genes. To test the hypothesis that chromosomal evolution is different in the fungi compared to other eukaryotes, synteny was compared between species of the major fungal taxa. Results: These analyses identified a novel form of evolution in which genes are conserved within homologous chromosomes, but with randomized orders and orientations. This mode of evolution is designated mesosynteny, to differentiate it from micro-and macrosynteny seen in other organisms. Mesosynteny is an alternative evolutionary pathway very different from macrosyntenic conservation. Surprisingly, mesosynteny was not found in all fungal groups. Instead, mesosynteny appears to be restricted to filamentous Ascomycetes and was most striking between species in the Dothideomycetes. Conclusions: The existence of mesosynteny between relatively distantly related Ascomycetes could be explained by a high frequency of chromosomal inversions, but translocations must be extremely rare. The mechanism for this phenomenon is not known, but presumably involves generation of frequent inversions during meiosis

    X-ray Absorption Linear Dichroism at the Ti K-edge of TiO2 anatase single crystal

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    Anatase TiO2 (a-TiO2) exhibits a strong X-ray absorption linear dichroism with the X-ray incidence angle in the pre-edge, the XANES and the EXAFS at the titanium K-edge. In the pre-edge region the behaviour of the A1-A3 and B peaks, originating from the 1s-3d transitions, is due to the strong pp-orbital polarization and strong p−dp-d orbital mixing. An unambiguous assignment of the pre-edge peak transitions is made in the monoelectronic approximation with the support of ab initio finite difference method calculations and spherical tensor analysis in quantitative agreement with the experiment. It is found that A1 is mostly an on-site 3d-4p hybridized transition, while peaks A3 and B are non-local transitions, with A3 being mostly dipolar and influence by the 3d-4p intersite hybridization, while B is due to interactions at longer range. Finally, peak A2 which was previously assigned to a transition involving pentacoordinated titanium atoms exhibits a quadrupolar angular evolution with incidence angle. These results pave the way to the use of the pre-edge peaks at the K-edge of a-TiO2 to characterize the electronic structure of related materials and in the field of ultrafast XAS where the linear dichroism can be used to compare the photophysics along different axes.Comment: 43 pages, 19 figure

    Temperature dependence of the excitation spectrum in the charge-density-wave ErTe3_3 and HoTe3_3 systems

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    We provide optical reflectivity data collected over a broad spectral range and as a function of temperature on the ErTe3_3 and HoTe3_3 materials, which undergo two consecutive charge-density-wave (CDW) phase transitions at TCDW1T_{CDW1}= 265 and 288 K and at TCDW2T_{CDW2}= 157 and 110 K, respectively. We observe the temperature dependence of both the Drude component, due to the itinerant charge carriers, and the single-particle peak, ascribed to the charge-density-wave gap excitation. The CDW gap progressively opens while the metallic component gets narrow with decreasing temperature. An important fraction of the whole Fermi surface seems to be affected by the CDW phase transitions. It turns out that the temperature and the previously investigated pressure dependence of the most relevant CDW parameters share several common features and behaviors. Particularly, the order parameter of the CDW state is in general agreement with the predictions of the BCS theory

    Raman scattering evidence for a cascade-like evolution of the charge-density-wave collective amplitude mode

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    The two-dimensional rare-earth tri-tellurides undergo a unidirectional charge-density-wave (CDW) transition at high temperature and, for the heaviest members of the series, a bidirectional one at low temperature. Raman scattering experiments as a function of temperature on DyTe3_3 and on LaTe3_3 at 6 GPa provide a clear-cut evidence for the emergence of the respective collective CDW amplitude excitations. In the unidirectional CDW phase, we surprisingly discover that the amplitude mode develops as a succession of two mean-field, BCS-like transitions in different temperature ranges

    Evidence for coupling between collective state and phonons in two-dimensional charge-density-wave systems

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    We report on a Raman scattering investigation of the charge-density-wave (CDW), quasi two-dimensional rare-earth tri-tellurides RRTe3_3 (RR= La, Ce, Pr, Nd, Sm, Gd and Dy) at ambient pressure, and of LaTe3_3 and CeTe3_3 under externally applied pressure. The observed phonon peaks can be ascribed to the Raman active modes for both the undistorted as well as the distorted lattice in the CDW state by means of a first principles calculation. The latter also predicts the Kohn anomaly in the phonon dispersion, driving the CDW transition. The integrated intensity of the two most prominent modes scales as a characteristic power of the CDW-gap amplitude upon compressing the lattice, which provides clear evidence for the tight coupling between the CDW condensate and the vibrational modes

    Electronic correlations in iron-pnictide superconductors and beyond; what can we learn from optics

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    The Coulomb repulsion, impeding electrons' motion, has an important impact on the charge dynamics. It mainly causes a reduction of the effective metallic Drude weight (proportional to the so-called optical kinetic energy), encountered in the optical conductivity, with respect to the expectation within the nearly-free electron limit (defining the so-called band kinetic energy), as evinced from band-structure theory. In principle, the ratio between the optical and band kinetic energy allows defining the degree of electronic correlations. Through spectral weight arguments based on the excitation spectrum, we provide an experimental tool, free from any theoretical or band-structure based assumptions, in order to estimate the degree of electronic correlations in several systems. We first address the novel iron-pnictide superconductors, which serve to set the stage for our approach. We then revisit a large variety of materials, ranging from superconductors, to Kondo-like systems as well as materials close to the Mott-insulating state. As comparison we also tackle materials, where the electron-phonon coupling dominates. We establish a direct relationship between the strength of interaction and the resulting reduction of the optical kinetic energy of the itinerant charge carriers

    Synthesis of Single Phase Hg-1223 High Tc Superconducting Films With Multistep Electrolytic Process

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    We report the multistep electrolytic process for the synthesis of high Tc single phase HgBa2Ca2Cu3O8+&#61540; (Hg-1223) superconducting films. The process includes : i) deposition of BaCaCu precursor alloy, ii) oxidation of BaCaCu films, iii) electrolytic intercalation of Hg in precursor BaCaCuO films and iv) electrochemical oxidation and annealing of Hg-intercalated BaCaCuO films to convert into Hg1Ba2Ca2Cu3O8+&#61540; (Hg-1223). Films were characterized by thermo-gravimetric analysis (TGA) and differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrolytic intercalation of Hg in BaCaCuO precursor is proved to be a novel alternative to high temperature-high pressure mercuration process. The films are single phase Hg-1223 with Tc = 121.5 K and Jc = 4.3 x 104 A/cm2.Comment: 17 Pages, 10 Figures. Submitted to Superconductor Science and Technolog
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