Benefícios Da Adequação Postural Em Cadeira De Rodas E Fatores Que Interferem Em Sua Utilização: Uma Revisão Sistemática

Seating and positioning are an assistive technology resource that aims to improve functional performance in the wheelchair. The aim of this paper was to find in the literature studies that addressed the benefits of seating and positioning in a wheelchair and factors that interfere with the prescription and use of this technology. Articles found that discuss the benefits addressed: the functionality and respiratory function; the pressure ulcer prevention; and user satisfaction and the family with assistive technology. Articles discussing the factors linked to prescription and use of adapting wheelchairs are those that address the environmental factors, components and wheelchair accessories. There are factors involved in the prescription process to achieve its benefits through its use, the prescribed process must have an interdisciplinary and biopsychosocial approach applied individually to each patient.5218119

Thermochemical insights on the conformational energetics of azepan and azepan-1-ylacetonitrile

© 2014 American Chemical Society. This paper is concerned with computational and experimental thermochemical studies of azepan and azepan-1-ylacetonitrile, molecules whose flexible ring structure provides several conformational forms with low energy barriers among them. The computational study describes the energetic analysis of the six most stable conformers on the potential energy surfaces and the determination of their gas-phase standard enthalpy of formation at the reference temperature of 298.15 K. The same gas-phase enthalpic parameters are also derived from the enthalpies of formation in the liquid phase and the enthalpies of vaporization, at T = 298.15 K, determined experimentally using the combustion calorimetry and the Calvet microcalorimetry techniques, respectively. The experimental data reported in this work for the two titled compounds together with other available in the literature for related molecules enabled the establishment of an increments scheme, providing a reliable approach on the prevision of gas-phase enthalpy of formation of cyclic/acyclic hydrocarbons and amines. Complementary, natural bond orbital (NBO) calculations were also performed, allowing an advance on the analysis of the structural and reactivity behavior of these type of compounds.Peer Reviewe

Energetic and Structural Properties of Two Phenolic Antioxidants: Tyrosol and Hydroxytyrosol

Theoretical and experimental studies on the energetic, structural and some other relevant physicochemical properties of the antioxidant tyrosol (1), hydroxytyrosol (1OH) molecules and the corresponding radicals 1 and 1O are reported in this work. The experimental values of the gas-phase enthalpy of formation, ΔH (g), in kJ·mol, of 1 (-302.4 ± 3.4) and 1OH (-486.3 ± 4.1) have been determined. Quantum chemical calculations, at DFT (M05-2X) and composite ab initio G3 and G4 levels of theory, provided results that served to (i) confirm the excellent consistency of the experimental measurements performed, (ii) establish that the stabilizing effect of H-bond of hydroxyethyl chain and aromatic ring (OH···π interaction) is smaller in radicals than in parent molecules, (iii) deduce - combining experimental data in isodesmic reactions - ΔH (g) of radicals 1 (-152.3 ± 4.4 kJ·mol) and 1O (-370.6 ± 3.8 kJ·mol), (iv) estimate a reliable O-H bond dissociation enthalpy, BDE of 1 (368.1 ± 5.6 kJ·mol) and of 1OH (333.7 ± 5.6 kJ·mol), and (v) corroborate - using >BDE criteria> - than 1OH is a more effective antioxidant than 1.Peer Reviewe

Thermodynamic properties of 2,7-di-tert-butylfluorene - An experimental and computational study

This work presents a comprehensive experimental and computational study of the thermodynamic properties of 2,7-di-tert-butylfluorene. The standard (p = 0.1 MPa) molar enthalpy of formation in the crystalline phase was derived from the standard molar energy of combustion, measured by static bomb combustion calorimetry. The enthalpies and temperatures of transition between condensed phases were determined from DSC experiments. The vapour pressures of the crystalline and liquid phases were measured between (349.14 and 404.04) K, using two different experimental methods. From these results the standard molar enthalpies, entropies and Gibbs energies of sublimation and of vaporization were derived. The enthalpy of sublimation was also determined using Calvet microcalorimetry. The thermodynamic stability of 2,7-di-tert-butylfluorene in the crystalline and gaseous phases was evaluated by the determination of the standard Gibbs energies of formation, at the temperature 298.15 K, and compared with the ones reported in the literature for fluorene. A computational study at the G3(MP2)//B3LYP and G3 levels has been carried out. A conformational analysis has been performed and the enthalpy of formation of 2,7-di-tert-butylfluorene has been calculated, using atomization and isodesmic reactions. The calculated enthalpies of formation have been compared to the experimental values.Peer Reviewe

Thermochemistry of R-SH group in gaseous phase: Experimental and theoretical studies of three sulfur imidazole derivatives

In the present work, we report the standard combustion energies of 2-mercapto-1-methylimidazole, 2-mercapto-5-aminobenzimidazole and 2-mercapto-5-methoxybenzimidazole, obtained experimentally from measurements with a rotatory-bomb combustion calorimeter. With these data, for each one of the three aforementioned compounds, the corresponding standard molar combustion enthalpies and the standard molar enthalpies of formation, in the crystalline phase, are calculated. The enthalpies of sublimation of each compound, obtained experimentally using a Calvet Setaram HT 1000 microcalorimeter, are also reported. Using the values of the enthalpies of formation in the crystalline phase and the enthalpies of sublimation, both at 298.15 K, for each compound, the corresponding standard molar enthalpies of formation in gas phase were calculated. Complementary, the enthalpies of formation in the gaseous phase were derived from theoretical calculations made with Gaussian-n composite methodology with n = 3 and 4. The experimental and computational studies suggest that in gaseous phase, the form more stable of each compound is the thione form.Peer Reviewe