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AimTo evaluate visual dysfunction and its correlation with structural changes in the retina in patients with Alzheimer's disease (AD).MethodsPatients with AD (n=24) and controls (n=24) underwent evaluation of visual acuity (VA), color vision (using the Farnsworth and L’Anthony desaturated (D) 15 color tests), and contrast sensitivity vision (CSV; using the Pelli-Robson chart and CSV-1000E test) to measure visual dysfunction. Structural measurements of the retinal nerve fiber layer (RNFL) and macular thickness were obtained using spectral domain-optical coherence tomography (SD-OCT).ResultsCSV at three of the four spatial frequencies was significantly worse in AD patients than in controls. Color vision was significantly affected in AD patients based on the Farnsworth color test. Compared with controls, macular thinning was detected in all sectors except the fovea, and the RNFL exhibited significant thinning in the superior quadrant and lower average thickness (P<0.05). CSV was the functional parameter most strongly correlated with structural measurements in patients with AD. Color vision was strongly associated with macular volume (r>0.70, P<0.05). VA at different levels of contrast was associated with macular and RNFL thickness.ConclusionsPatients with AD had visual dysfunction that correlated with structural changes evaluated by SD-OCT. Macular measurements may be reliable indicators of visual impairment in AD patients.

Dew points have been measured for binary propane or n-butane + carbon dioxide mixtures at pressures from 1.2 × 105 to 34.9 × 105 Pa and temperatures from 192.6 to 274.8 K, four ternary propane or n-butane + carbon dioxide + water mixtures from 1.1 × 105 to 20.7 × 105 Pa and temperatures from 247.5 to 289.0 K, and eight quaternary propane or n-butane + carbon dioxide + water + methanol mixtures from 1.1 × 105 to 21.8 × 105 Pa and temperatures from 249.8 to 289.9 K. The results are analyzed in terms of a predictive EF-EOS excess-function equation of state method based on the zeroth-approximation of Guggenheim's reticular model. This method has been chosen because it can be used to adequately predict the dew points of all the mixtures of our interest in the dew temperature and pressure ranges. In fact, the model reproduces the experimental dew-point temperature data within an AAD (absolute average deviation) of 1.6 and 1.3 K for the binary systems, between 0.1 and 2.5 K for the ternary systems, and between 0.0 and 5.1 K for the quaternary systems. The experimental results obtained for ternary propane or n-butane + carbon dioxide + water mixtures at pressure values higher than 5 × 105 Pa were also compared to a predictive EOS (equation of state) model. It reproduced experimental dew-point temperature data within AAD between 0.0 and 5.5 K.

Experimental measurements of dew points for 14 methane + carbon dioxide + water + methanol mixtures at pressures between 1.0 × 10⁵ and 59.1 × 10⁵ Pa in the temperature range from 241.6 to 288.8 K were made. The experimental results obtained on the quaternary systems were analyzed in terms of a predictive EF−EOS (excess function−equation of state) method, which reproduced experimental dew-point temperature data within an AAD (absolute average deviation) of between 0.0 and 1.9 K.

Dew points for two synthetic natural gas (SNG) mixtures between 1.2 × 10⁵ and 81.8 × 10⁵ Pa in the temperature range from 213.6 to 261.4 K, four SNG + water mixtures between 1.1 × 10⁵ and 41.0 × 10⁵ Pa and temperatures from 244.7 to 288.1 K, and four SNG + water + methanol mixtures between 1.1 × 10⁵ and 20.7 × 10⁵ Pa and temperatures from 247.6 to 288.6 K were experimentally determined. The experimental results obtained on the multicomponent systems were analyzed in terms of a predictive excess function−equation of state (EF−EOS) method, which reproduced experimental dew point temperature data with absolute average deviation (AAD) between 0.9 and 3.1 K for the dry systems, from 0.0 to 1.6 K for the systems with water, and from 0.0 to 3.0 K for the systems with water and methanol. The experimental results obtained for synthetic natural gas (SNG) + water mixtures at pressure values higher than 5 × 10⁵ Pa were also compared to a predictive equation of state (EOS) model. It reproduced experimental dew point temperature data within AAD between 1.8 and 5.3 K.

Experimental measurements of dew points for five synthetic natural gas (SNG) mixtures between 1.9 × 10⁵ and 106.0 × 10⁵ Pa in the temperature range from 195.5 to 277.3 K and nine SNG + water + methanol mixtures between 1.4 × 10⁵ and 73.1 × 10⁵ Pa and at temperatures from 237.3 to 288.2 K were determined. The experimental results obtained on the multicomponent systems were analyzed in terms of an equation of state chemical reticular method, which reproduced experimental dew-point temperature data within an absolute average deviation between 0.8 and 3.7 K for the dry systems and from 0.5 to 1.9 K for the systems with water and methanol.

Isothermal vapor−liquid equilibria (VLE) at 308.15 K have been measured for liquid 1,3-dioxolane or 1,4-dioxane + hexane or + cyclohexane or + ethanol mixtures. The VLE data were reduced using the Redlich−Kister equation, taking into consideration the vapor-phase imperfection in terms of the second molar virial coefficients. The excess molar Gibbs energies of all the studied mixtures are positive and range from 653 J·mol^-1 for 1,4-dioxane + ethanol and 1020 J·mol^-1 for 1,3-dioxolane + hexane.

Excess molar enthalpies,HE, at atmospheric pressure and 303.15 K are reported for binary mixtures of 1-chlorohexane with diethyl oxalate, diethyl malonate, diethyl succinate, diethyl glutarate, diethyl adipate, diethyl pimelate and diethyl sebacate. These experimental results, together with those obtained previously on the excess enthalpies of aliphatic diester+n-hexane mixtures, are interpreted in terms of molecular surface interactions between aliphatic, chlorinated and carboxylate groups. Comparison of the enthalpy interchange parameters reveals a decrease of the intermolecular interactions with decreasing intramolecular COO-COO distance in the diester molecule.

Isothermal vapor−liquid equilibria (VLE) at 313.15 K have been measured for liquid ethyl acetate + dibromomethane or + bromochloromethane or + 1,2-dichloroethane or + 1-bromo-2-chloroethane mixtures. The VLE data were reduced using the Redlich−Kister equation by taking into consideration the vapor-phase nonideality in terms of the second molar virial coefficients, and the liquid activity coefficients were correlated by means of the Margules, van Laar, Wilson, NRTL, and UNIQUAC equations. The thermodynamic consistency of the experimental data was checked by means of the test of Van Ness et al. in the version of Fredenslund et al. The excess molar Gibbs energies of all of the studied mixtures are negative and range from −75 J mol^-1 for ethyl acetate + 1-bromo-2-chloroethane to −300 J mol^-1 for ethyl acetate + bromochloromethane at a mole fraction of x = 0.5.