Carbon Adsorbents With Dual Porosity for Efficient Removal of Uremic Toxins and Cytokines from Human Plasma.

The number of patients with chronic kidney disease increases while the number of available donor organs stays at approximately the same level. Unavoidable accumulation of the uremic toxins and cytokines for these patients comes as the result of malfunctioning kidneys and their high levels in the blood result in high morbidity and mortality. Unfortunately, the existing methods, like hemodialysis and hemofiltration, provide only partial removal of uremic toxins and/or cytokines from patients' blood. Consequently, there is an increasing need for the development of the extracorporeal treatments which will enable removal of broad spectrum of uremic toxins that are usually removed by healthy kidneys. Therefore, in this work we developed and tested ordered mesoporous carbons as new sorbents with dual porosity (micro/meso) that provide selective and efficient removal of a broad range of uremic toxins from human plasma. The new sorbents, CMK-3 are developed by nanocasting methods and have two distinct pore domains, i.e. micropores and mesopores, therefore show high adsorption capacity towards small water soluble toxins (creatinine), protein-bound molecules (indoxyl sulfate and hippuric acid), middle molecules (ß-2-microglobulin) and cytokines of different size (IL-6 and IL-8). Our results show that small amounts of CMK-3 could provide selective and complete blood purification.

Exceptional gravimetric and volumetric CO2 uptake in a palladated NbO-type MOF utilizing cooperative acidic and basic, metal-CO2 interactions.

A novel NbO-type MOF is reported based on a palladated organic linker, showing a remarkable gravimetric and volumetric CO2 uptake, reaching 201.8 cm(3) g(-1) (9.0 mmol g(-1), 39.7 wt%) and 187.8 cm(3) cm(-3) at 273 K and 1 bar, respectively. Accurate theoretical calculations revealed that the exceptional CO2 uptake is due to the combination of Lewis base Pd(ii)-CO2 (24.3 kJ mol(-1)) and Lewis acid Cu(ii)-CO2 (30.3 kJ mol(-1)) interactions, as well as synergistic pore size effects.

Diffusion in a Fractal System.

The surface geometry of Vycor porous glass was examined by using the relative permeability (PR) technique in a H2O/He system. At a water relative pressure of approximately 0.3, a maximum is observed on the PR curve. This maximum is explained in terms of geometrical changes taking place due to the deposition of a water film on the internal Vycor surface. When the sample is dry, diffusion in a fractal system is found to be more appropriate in describing the process. When the sample is wet, the diffusion process obeys classical Knudsen theory for smooth cylinders. Copyright 1998 Academic Press.