84 research outputs found
A new species of Stenobiella Tillyard (Neuroptera, Berothidae) from Australia
Stenobiella variola sp. n., a new species of beaded lacewing (Neuroptera: Berothidae), is described and figured from south-eastern Australia. A preliminary key to Stenobiella species is presented
Competition for nitrogen between Pinus sylvestris and ectomycorrhizal fungi generates potential for negative feedback under elevated CO2
Long-term dynamics of aboveground fungal communities in a subalpine Norway spruce forest under elevated nitrogen input
The production and turnover of extramatrical mycelium of ectomycorrhizal fungi in forest soils: role in carbon cycling
LIPASE ADSORPTION AND INTERACTION WITH SURFACTANTS AT SILICA SURFACES WITH DIFFERENT HYDROPHOBICITY, AN ELLIPSOMETRY STUDY
Sphingoid bases inhibit acid-induced demineralization of hydroxyapatite
Calcium hydroxyapatite (HAp), the main constituent of dental enamel, is inherently susceptible to the etching and dissolving action of acids, resulting in tooth decay such as dental caries and dental erosion. Since the prevalence of erosive wear is gradually increasing, there is urgent need for agents that protect the enamel against erosive attacks. In the present study we studied in vitro the anti-erosive effects of a number of sphingolipids and sphingoid bases, which form the backbone of sphingolipids. Pretreatment of HAp discs with sphingosine, phytosphingosine (PHS), PHS phosphate and sphinganine significantly protected these against acid-induced demineralization by 80 ± 17%, 78 ± 17%, 78 ± 7% and 81 ± 8%, respectively (p < 0.001). On the other hand, sphingomyelin, acetyl PHS, octanoyl PHS and stearoyl PHS had no anti-erosive effects. Atomic force measurement revealed that HAp discs treated with PHS were almost completely and homogeneously covered by patches of PHS. This suggests that PHS and other sphingoid bases form layers on the surface of HAp, which act as diffusion barriers against H+ ions. In principle, these anti-erosive properties make PHS and related sphingosines promising and attractive candidates as ingredients in oral care products
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