Ultradian rhythms of activity in a wild subterranean rodent.

Many animals adapt their activity patterns to the best environmental conditions using daily rhythms. African mole-rats are among the mammals that have become models for studying how these rhythms can be entrained by light or temperature in experimental laboratory studies. However, it is unclear whether they exhibit similar circadian rhythms in their natural lightless, subterranean environment.

Laser fluorescence of dentin caries covered with a novel nano-filled sealant.

The aim of the present study was to assess the possibility to measure caries-induced laser fluorescence underneath a novel nano-filled fissure sealant. Sixty freshly extracted human teeth with occlusal dentine carious lesions were horizontally divided, exposing the respective lesion. Teeth were randomly assigned to three groups: (I) white fissure sealant with filler particles (Fissurit F, Voco), (II) clear fissure sealant without filler particles (Fissurit, Voco) and (III) novel experimental fissure sealant with nano-filler particles (Voco).

Heat generation caused by ablation of restorative materials with an ultrashort pulse laser (USPL) system.

Heat generation during the removal of dental restorative materials may lead to a temperature increase and cause painful sensations or damage dental tissues. The aim of this study was to assess heat generation in dental restoration materials following laser ablation using an ultrashort pulse laser (USPL) system. A total of 225 specimens of phosphate cement (PC), ceramic (CE), and composite (C) were used, evaluating a thickness of 1 to 5 mm each.

Free electron transfer--relations between molecule dynamics and reaction kinetics.

Electron transfer in non-polar media (alkanes, alkyl chlorides) exhibits some essential peculiarities. For instance the reaction of hetero-substituted aromatics with parent solvent radical cations results in the parallel formation of metastable donor radical cations and fragmentation products, in comparable amounts. The fragmentation products originate from a dissociative donor radical cation which decays extremely rapidly, i.