Proton beam irradiation induces invisible modifications under the surface of painted parchment.

Ion beam analysis plays an important role in cultural heritage (CH) studies as it offers a combination of simultaneous and complementary analytical techniques (PIXE/PIGE/RBS) and spatially resolved mapping functions. Despite being considered non-destructive, the potential risk of beam-induced modifications during analysis is increasingly discussed. This work focuses on the impact of proton beams on parchment, present in our CH in form of unique historical manuscripts.

Study of the geometry of open channels in a layer-bed-type microfluidic immobilized enzyme reactor.

This paper aims at studying open channel geometries in a layer-bed-type immobilized enzyme reactor with computer-aided simulations. The main properties of these reactors are their simple channel pattern, simple immobilization procedure, regenerability, and disposability; all these features make these devices one of the simplest yet efficient enzymatic microreactors. The high surface-to-volume ratio of the reactor was achieved using narrow (25-75 μm wide) channels.

Towards more reliable AFM force-curve evaluation: A method for spring constant selection, adaptive lever sensitivity calibration and fitting boundary identification.

This work discusses key issues regarding the atomic force microscopy (AFM) force-curve evaluation practice, which can affect the determined Young's modulus of the investigated sample. These issues are 1) the proper calibration of lever sensitivity and the effect of its variation between the measurements; 2) the selection of proper cantilever spring constant for the investigated sample; and 3) the selection of the fitting boundaries for the contact mechanics model-based force-curve evaluation. A method is proposed, which solves the above mentioned issues, namely, categorizes the obtained force-curves based on the relation between the elastic properties of the sample and the spring constant of the cantilever, and thus helps in the selection of the proper spring constant for the given surface; helps in the identification of the optimal model-fitting boundaries, and also, provides a way of adaptive lever sensitivity calibration.

Enhanced growth of tellurium nanowires under conditions of macromolecular crowding.

An unprecedented rate enhancement was observed in the wet-chemical synthesis of tellurium nanowires under crowded conditions of inert macromolecules. The synthesis was carried out at 105 °C using solutions of sodium tellurite (NaTeO) as a precursor, hydrazine (NH) as a reducing agent, and polyvinylpyrrolidone (PVP) as both a stabilizing and crowding agent. The PVP concentration was systematically varied between the dilute and crowding regimes up to 166 g l.