An extensive study of adsorption and diffusion of hydrogen atoms on (100) surfaces of fcc Au, Cu, Ag and P t was performed by means of DFT calculations. Bulk properties of those metals were calculated and compared with previous results. The adsorption distances and energies of the hydrogen atom on top, hollow and bridge sites of the (100) surfaces were calculated in order to elucidate preferential adsorption sites of hydrogen on each metal. All these calculations were done in conjunction with a study of charge distribution. Finally, diffusion of the H atom from the most stable adsorption site to the nearest neighbouring site was studied in order to obtain diffusion barrier and diffusion velocity values. The highest diffusion velocity was found to be v = 6.44 × 10 11 s −1 for the case of Ag, whereas the lowest was v = 1.13 × 10 7 s −1 for Au.

Human Adipose-derived mesenchymal stem/stromal cells (hASCs) are of great interest because of their potential for therapeutic approaches. The method described here covers every single step necessary for hASCs isolation from subcutaneous abdominal adipose tissue, multicolor phenotyping by flow cytometry, and quantitative determination of adipogenic differentiation status by means of lipid droplets (LDs) accumulation, and Western blot analysis. Moreover, to simultaneously analyze both LDs accumulation and cellular proteins localization by fluorescence microscopy, we combined Oil Red O (ORO) staining with immunofluorescence detection. For LDs quantification we wrote a program for automatic ORO-stained digital image processing implemented in Octave, a freely available software package. Our method is based on the use of the traditional low cost neutral lipids dye ORO, which can be imaged both by bright-field and fluorescence microscopy. The utilization of ORO instead of other more expensive lipid-specific dyes, together with the fact that the whole method has been designed employing cost-effective culture reagents (standard culture medium and serum), makes it affordable for tight-budget research laboratories. These may be replaced, if necessary or desired, by defined xeno-free reagents for clinical research and applications.

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