495 research outputs found

    Oral health-related quality of life in US adults with type 2 diabetes.

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    This dissertation focused on the relationship between type 2 diabetes (T2DM) and oral health-related quality of life (OHRQoL) and the factors associated with this relationship in the US. The objectives of the dissertation research were a three-part process: (1) to understand the relationships of T2DM with poor OHRQoL, clarify risk and preventive factors that affect this association, and identify research gaps in the literature, (2) to analyze risk factors associated with poor OHRQoL in US adults with T2DM using a nationally representative random probability cluster sample, and (3) to apply structural equation modeling (SEM) to a simplified Andersen’s Behavioral Model (ABM) to analyze the causal effects of T2DM and other factors on OHRQoL in adults from a nationally representative survey in the US. The first, second, and third objectives were met in Aim 1, Aim 2, and Aim 3, respectively. In Aim 1, there were 16 empirical articles included the systematic review that examined the association between T2DM and OHRQoL. Half of the reviewed studies did not include a control or comparison group (participants with non-T2DM). All investigations used samples of convenience, or surveys at the community level outside of the US. No studies were conducted at the national level in the US. Five studies included used only bivariate analysis and did not control for confounders. The remaining 11 studies used multivariate analysis, but none of them used a theoretical framework to guide their approach. Limited evidence supported the association between T2DM and poor OHRQoL. Some data support analyses that an increased susceptibility to periodontal disease, dry mouth, and dental caries may have negative effects on well-being and quality of life among individuals with T2DM. The findings of Aim 1 highlight the need for further research. In Aim 2, the 2003-2004 National Health and Nutrition Examination Survey (NHANES) data set was used. The sample included 2,945 participants aged 20 or older sampled with a probability-based cluster design representing 131,397,654 million persons in the US population. Multiple logistic regression was used to predict severity scores (OHIP-ADD) and prevalence scores (OHIP-SC) with the ABM theoretical framework. We found that OHRQoL was poorer among US adults with T2DM, especially those with uncontrolled glycemia. Risk factors for poor OHRQoL included untreated dental caries, periodontal disease, unmet denture needs, obesity, female gender, African American ethnicity, and low income. Higher education, private dental coverage, and annual dental prophylaxis was associated with higher OHRQoL. In Aim 3, the analysis of a nationally representative sample of 2,798 participants aged 20 or older representing 124,525,899 individuals in the US population was done. We applied SEM to a simplified three-factor Andersen’s model to analyze the causal effects of T2DM and other factors on OHRQoL. Causal pathways of the interrelationships of T2DM, need, personal health practices and use of services with OHRQoL were analyzed in a simplified three-factor ABM. Using SEM, T2DM had an impact on need, which in turn, had direct and indirect effects on OHRQoL. Need also influenced personal health practices and use of services, which in turn, affected OHRQoL. Education and income also affected personal health practices and use of services. In summary, a theory-driven, practice-validated conceptual model with rigorous statistical methodology using a nationally representative sample in the US was used to analyze the association and pathways of T2DM and OHRQoL, as well as factors associated with these relationships. The present research indicates that T2DM negatively affected OHRQoL in US adults. Risk factors for poor OHRQoL (in descending order of importance) were current smoking, untreated dental caries, uncontrolled T2DM, unmet denture need, female gender, obesity, African American ethnicity, and periodontal disease. Protective factors from OHRQoL impairment were private dental insurance, college education, and annual dental prophylaxis. Moreover, need directly and indirectly influenced OHRQoL. Personal health practices and use of services also had affected OHRQoL

    Application of the Taguchi method to determine optimized parameters for designing brake of hand winch

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    Brakes are used to stop movement or adjust speed to ensure safety for mechanisms or machines. In this paper, the brake applied to hand winch will be studied. This hand winch has been studied by us in previous stages. However, the disadvantage of the winch is that the drum wall attached to the friction surfaces is not reasonable in terms of layout, as well as the parameters to optimize braking moment have not been calculated. A new brake structure is proposed in this study to solve the above problem. This structure does not use the drum wall as the friction surface. It does not affect the drum wall and it is easy to replace the friction surface when necessary. Instead, the cone brake is suitable for the structure brake and the size, structure, and design load. To determine the optimal parameters of the brake structure, the article will analyze the theory, and experiment design. The objective function is the maximum braking torque. Constraints are hand winch parameters, installation, friction surface material, and loading conditions. The corresponding factors are coded according to the Taguchi method, the orthogonal planning matrix is L18. Using Minitab software to analyze the Signal/Noise ratio, the study determined the optimal values for five factors including screw thread pitch, coefficient of friction (screw thread), cone angle, friction coefficient (brake), and large cone brake radius. Research results have selected the optimal parameters of the brake, and the optimal values have satisfied the constraints. The torque at the cone brake is greater than that of the disc brake approximately 37.7 %. The pressure at the friction surface is reduced by about 55 % compared to the disc brake surfac

    Privatisation of the shipping industry in Vietnam : the benefit, problems and proposals

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    Efficient Microparticle Trapping with Plasmonic Annular Apertures Arrays

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    In this work, we demonstrate trapping of microparticles using a plasmonic tweezers based on arrays of annular apertures. The transmission spectra and the E- field distribution are simulated to calibrate the arrays. Theoretically, we observe sharp peaks in the transmission spectra for dipole resonance modes and these are redshifted as the size of the annular aperture is reduced. We also expect an absorption peak at approximately 1,115 um for the localised plasmon resonance. Using a laser frequency between the two resonances, multiple plasmonic hotspots are created and used to trap and transport micron and submicron particles. Experimentally, we demonstrate trapping of individual 0.5 um and 1 um polystyrene particles and particle transportation over the surface of the annular apertures using less than 1.5 mW/um2 incident laser intensity at 980 nm

    Standard gradient models and crack simulation

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    The standard gradient models have been intensively studied in the literature, cf. Fremond (1985) or Gurtin (1991) for various applications in plasticity, damage mechanics and phase change analysis. The governing equations for a solid have been introduced essentially from an extended version of the virtual equation. It is shown here first that these equations can also be derived from the formalism of energy and dissipation potentials and appear as a generalized Biot equation for the solid. In this spirit, the governing equations for higher gradient models can be straightforwardly given. The interest of gradient models is then discussed in the context of damage mechanics and crack simulation. The phenomenon of strain localization in a time-dependent or time-independent process of damage is explored as a convenient numerical method to simulate the propagation of cracks, in relation with some recent works of theliterature, cf. Bourdin Marigo [3], Lorentz al  [5], Henry al [12]
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