Study of colloidal properties of natural and Al-pillared smectite and removal of copper ions from an aqueous solution.

In this study, an Al-pillared smectite was synthesized and changes in its colloidal properties were investigated. The pillaring solution was prepared by mixing 0.4 mol L(-1) NaOH and 0.2 mol L(-1) AlCl3.6H2O solutions. Intercalated clays were heated to obtain the pillared clay, and X-ray diffractometry (XRD), X-ray fluorescence (XRF), Fourier transform infrared (FTIR) spectroscopy and N2 sorption/desorption isotherms analysis were done to characterize the changes in clay properties. Moreover, adsorption experiments were carried out in order to evaluate the capacity of the pillared clays to remove Cu2+ from an aqueous solution and to characterize the interaction between adsorbent and adsorbate. The results indicate that the natural clay has a basal spacing of 1.26 nm, whereas the pillared clays reached 1.78 nm (500°C) and 1.80 nm (350°C) after calcination. XRF analysis revealed an increase in the Al3+ in the pillared clay as compared to the natural clay. The surface area and pore volume (micro and mesoporous) were higher for the pillared clays. Experimental data from the adsorption experiment were fit to Langmuir and Freundlich and Temkin adsorption models, and the former one was the best fit (highest r2 value) for all the clays and lower standard deviation (Δg%) for the natural clay. On the other hand, the Temkin model exhibited Δg% value lower for the pillared clays. Thermodynamics parameters demonstrate that the Cu2+ adsorption process is spontaneous for all the clays, but with higher values for the pillared materials. In addition, application of the Dubinin-Radushkevich model revealed that the bond between the metal and the clay are weak, characterizing a physisorption.

The essential health reform in Chile; a reflection on the 1952 process.

The authors claim that the critical health reform in Chilean history was the establishment of the National Health Service (NHS) in 1952. The development of modern Chilean health care since the end of the 19th century is discussed both in terms of the prevailing health situation and the subsequent evolution of institutions and policies, with an emphasis on the social and political conditions that led to the creation of the NHS in 1952. From this analysis and from a comparison of infant mortality rates among Latin American countries during the same period, the authors infer that the 1952 health reform was the social and political benchmark that allowed Chile to exhibit the relatively favorable health situation it still enjoys. Using Cavanaugh's scheme, it is clear that the "first-generation reform" was the reform imposed by the military regime in the early 1980s, which aimed to change the orientation of the health system. Similarly, the "second-generation reform" was that implemented by the democratic administrations of the early 1990s to reverse the harm done by their military predecessors. The rapid aging of the population and the advent of new technologies pose a challenge to the insurance system's coverage capacity and threaten the sustainability of all health systems. The implementation of universal, comprehensive, collective health systems, managed under the most integrated authority political conditions will allow, is emphasized as an appropriate solution for developed and developing countries alike.

La Organización Mundial de la Salud y la planificación / The WHO contribution to health planning

The basic concepts, evolution and practice of health planning are described, in the context of WHO role. Special emphasis is given to the Cendes-OPS methodology, to be this procedure a more specific, articulated and implemented widely in the American region. Finally, future projections of these activities are given