Excess enthalpy and entropy of aqueous tetramethylguanidinium methanesulfonate and trifluoromethanesulfonate solutions

Relative apparent molal heat contents, φ_L, are reported for the tetramethylguanidinium salts of methanesulfonic (MS) and trifluoromethanesulfonic (TFMS) acids. Relative partial molal heat contents, L?₂, are calculated and combined with previously reported activity coefficient data, to yield excess entropies. It is found that the values of L?₂ make the principal contribution to the excess entropies of Me₄GuMS solutions while the excess free energies, as calculated from activity coefficients, make the greatest contribution to the excess entropies of Me₄GuTFMS solutions.     

A direct method for measuring adsorption from solution onto solids

A direct method of measuring solution adsorption onto a solid has been developed. The results are exactly the same as those given by the conventional method of measuring the change in composition of the solution upon contacting the adsorbent. The development is cast in the terms of Gibbsian surface concepts, from which the correct thermodynamic significance of adsorption measurements made by directly analyzing material adsorbed on the solid can be understood. The method was tested for the adsorption of Na-Laurate and n-hexanol from aqueous and n-decane solutions, and typical isotherms are presented. The various realized and potential advantages of the method are discussed. The most important of these are the ability to measure adsorption in complex systems with a negligible change in solution composition, and the possibility of ameliorating in certain situations some of the difficulties in measuring adsorption at high concentrations or on low surface area solids.     

The ionization of perchloric and hydrofluoric acids in aqueous solution

Cyclical bifurcated hydrogen bonded structures are proposed for aqueous solutions of hydrofluoric acid and for the bifluoride ion which are consistent with the spectral data. The structure proposed for HF is also applicable to solutions in organic solvents. Raman spectra of tetramethylguanidinium perchlorate suggest that the corresponding Raman spectra of perchloric acid solutions may not be interpreted in terms of a completely dissociated acid. Other evidence including activity coefficient, heat capacity and partial molal volume data suggest that there is some association in relatively dilute perchloric acid solutions between the perchlorate ion and the hydrated proton. This association decreases in concentrated aqueous solutions.     

A phase I, randomized study of combined IL-2 and therapeutic immunisation with antiretroviral therapy

Background  

Fully functional HIV-1-specific CD8 and CD4 effector T-cell responses are vital to the containment of viral activity and disease progression. These responses are lacking in HIV-1-infected patients with progressive disease. We attempted to augment fully functional HIV-1-specific CD8 and CD4 effector T-cell responses in patients with advanced chronic HIV-1 infection.