Detecting dipolarity of the geomagnetic field in the paleomagnetic record.

Recovering the geomagnetic field strength in the past is key to understanding deep Earth dynamics and detecting potential geodynamo regimes throughout the history of Earth. To better constrain the predictive power of the paleomagnetic record, we propose an approach based on the analysis of the dependency between geomagnetic field strength and inclination (angle made by the horizontal with the field lines). Based on the outcomes of statistical field models, we show that these two quantities should correlate for a wide range of Earth-like magnetic fields, even with enhanced secular variation, persistent nonzonal components, and severe noise contamination.

A mechanistic study of gold nanoparticles catalysis of O reduction by ascorbate and hydroethidine, investigating reactive oxygen species reactivity.

In this work, the mechanism of dioxygen reduction catalysed by gold nanoparticles (AuNPs) by two electron donors was investigated, , by sodium ascorbate and hydroethidine, focusing on potential ROS (reactive oxygen species) formation, such as O˙ and HO. According to our results, when AuNPs catalyse the reduction of O, ROS are formed only as intermediates on the surface of nanoparticles, and they are unavoidably reduced to water, catalysed by the AuNPs. Thus, the statement on ROS production in the presence of AuNPs often reported in the literature is excessive.

Fully discrete approximation schemes for rate-independent crack evolution.

Over the past two decades, several distinct solution concepts for rate-independent evolutionary systems driven by non-convex energies have been suggested in an attempt to model properly jump discontinuities in time. Much attention has been paid in this context to the modelling of crack propagation. This paper studies two fully discrete (in time and space) approximation schemes for the rate-independent evolution of a single crack in a two-dimensional linear elastic material.

Modulation of the Directionality of Hole Transfer between the Base and the Sugar-Phosphate Backbone in DNA with the Number of Sulfur Atoms in the Phosphate Group.

This work shows that S atom substitution in phosphate controls the directionality of hole transfer processes between the base and sugar-phosphate backbone in DNA systems. The investigation combines synthesis, electron spin resonance (ESR) studies in supercooled homogeneous solution, pulse radiolysis in aqueous solution at ambient temperature, and density functional theory (DFT) calculations of in-house synthesized model compound dimethylphosphorothioate (DMTP(O)═S) and nucleotide (5'--methoxyphosphorothioyl-2'-deoxyguanosine (G-P(O)═S)). ESR investigations show that DMTP(O)═S reacts with Cl to form the σσ* adduct radical -P-S[Formula: see text]Cl, which subsequently reacts with DMTP(O)═S to produce [-P-S[Formula: see text]S-P-].