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In many applications of the atmospheric pressure plasmas, the plasma is generated in chambers that enclose samples to be treated. In the case of plasma treatments of water or water-containing materials, the humidity in gaseous medium rises during the treatment, and this affects considerably the plasma generation of reactive oxygen and nitrogen species (RONS). In this study, Fourier transform infrared absorption spectroscopy is used to investigate the kinetics of reactive species generated by surface dielectric barrier (SDBD) micro-plasma in a small volume of atmospheric air (0.5 L) enclosed in a discharge chamber. The investigations were made for dry air (in absence of liquid water) and for humid air in presence of liquid water. The SDBD plasma contributes to desorption of water from the inner wall of the discharge chamber and enhances evaporation of liquid water, which increases air humidity and decreases the generation rates of reactive species. Kinetics of RONS generated in small samples of liquid water in contact with discharge medium is investigated by ex situ UV absorption spectroscopy measurements of plasma treated water. [ABSTRACT FROM AUTHOR]

Atomic force microscopy (AFM) indentation has become an important technique for quantifying the mechanical properties of live cells at nanoscale. However, determination of cell elasticity modulus from the force–displacement curves measured in the AFM indentations is not a trivial task. The present work shows that these force–displacement curves are affected by indenter-cell adhesion force, while the use of an appropriate indentation model may provide information on the cell elasticity and the work of adhesion of the cell membrane to the surface of the AFM probes. A recently proposed indentation model (Sirghi, Rossi in Appl Phys Lett 89:243118, ), which accounts for the effect of the adhesion force in nanoscale indentation, is applied to the AFM indentation experiments performed on live cells with pyramidal indenters. The model considers that the indentation force equilibrates the elastic force of the cell cytoskeleton and the adhesion force of the cell membrane. It is assumed that the indenter-cell contact area and the adhesion force decrease continuously during the unloading part of the indentation (peeling model). Force–displacement curves measured in indentation experiments performed with silicon nitride AFM probes with pyramidal tips on live cells (mouse fibroblast Balb/c3T3 clone A31-1-1) in physiological medium at 37°C agree well with the theoretical prediction and are used to determine the cell elasticity modulus and indenter-cell work of adhesion. [ABSTRACT FROM AUTHOR]