Caries, antemortem tooth loss and tooth wear observed in indigenous peoples and Russian settlers of 16th to 19th century West Siberia.

OBJECTIVE: Increased prevalence of dental caries evidently is correlated with increasing intake of sugar and carbohydrate-rich foods. Preceding and accompanying this dietary alteration might have been a shift from a hunting-and-gathering subsistence strategy to one based on agriculture. We corroborated this conjecture by means of a study on the prevalence of caries, antemortem tooth loss (AMTL) and tooth wear among 16th to 19th century hunter-gatherers and agriculturalists who co-existed in West Siberia. DESIGN: Indigenous skeletons (n = 75) exhumed from Tatar, Selkup, Khant, and Nenet graves along with Russian settler skeletons (n = 79) from Izyuk were examined. The prevalence of caries, AMTL and tooth wear among the indigenous peoples were compared with those among the Russian settlers. The resulting statistical inferences were tested using package R. RESULTS: The agriculturalist Russian settlers showed a significantly higher prevalence of dental caries (11.88%) than did the non-agriculturalist indigenous Siberian people (3.85%). Among the latter, the prevalence was the lowest in the Khanty and the highest in the Tatars, suggesting that caries differently affected each sub-group of indigenous Siberian people. Correspondingly to the case of dental caries, the Russian settlers' AMTL prevalence also was higher than that of the indigenous Siberians, regardless of age. On the other hand, the native Siberians and the Russian settlers did not show statistical differences in tooth wear. CONCLUSION: In the study on 16th to 19th century West Siberian populations, we were able to corroborate our presumption that agriculturalists ingesting a carbohydrate-rich diet would have higher rates of dental caries and AMTL than would hunter-gatherers.

From lignocellulosic biomass to furans via 5-acetoxymethylfurfural as an alternative to 5-hydroxymethylfurfural.

A facile pathway to furan derivatives from lignocellulosic biomass via 5-acetoxymethylfurfural (AMF) was developed. AMF possesses advantageous properties due to its less-hydrophilic acetoxymethyl group relative to the hydroxymethyl group of 5-hydroxymethylfurfural (HMF). The hydrophobicity and chemical stability of AMF allowed practical isolation and purification to afford a highly pure product of up to 99.9 %. AMF was produced in good to excellent yields under mild conditions from 5-chloromethylfurfural (CMF) and alkylammonium acetates, both of which could be obtained directly from lignocellulosic biomass. Heterogeneous reactions with polymer-supported alkylammonium acetates were also established; this showed the feasibility of a continuous process for this pathway. AMF could be transformed into various promising furanic compounds, such as 2,5-furandicarboxylic acid (FDCA), 2,5-furandimethanol (FDM), and 5-hydroxymethyl-2-furanoic acid (HFA), in high yields.