Fluoride affects bone repair differently in mice models with distinct bone densities

We grouped mice [strains: C57BL/6J (n = 32) and C3H/HeJ (n = 32)] to address the influence of bone density on fluoride's (F's) biological effects. These animals received low-fluoride food and water containing 0 (control group) or 50 ppm of F for up to 28 days. The upper left central incisor was extracted, and the left maxilla was collected at 7, 14, 21, and 28 days for histological and histomorphometric analysis to estimate bone neoformation. Our results showed bone neoformation in all of the evaluated groups, with the presence of bone islets invading the center of the alveoli when replacing the existing connective tissue. Curiously, this biological phenomenon was more evident in the C57BL/6J strain. The histomorphometric analysis confirmed the histological findings in relation to the amount of new bone tissue and showed a decrease in C3H/HeJ mice (control group). Altogether, our results showed differential effects of fluoride bone metabolism, confirming a genetic component in susceptibility to the effects of fluoride. (C) 2016 Elsevier GmbH. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Univ Sao Paulo, Bauru Sch Dent, Dept Biol Sci, Al Octavio Pinheiro Brisolla 9-75, BR-17012901 Sao Paulo, BrazilUniv Fed Sao Carlos, Dept Genet & Evolut, Ctr Biol Sci & Hlth, Km 235, BR-13560970 Sao Paulo, BrazilSao Paulo State Univ, Biosci Inst, Dept Chem & Biochem, Lab Bioassays & Cellular Dynam, Rubiao Jr S-N, BR-18618970 Sao Paulo, BrazilSao Paulo State Univ, Biosci Inst, Dept Chem & Biochem, Lab Bioassays & Cellular Dynam, Rubiao Jr S-N, BR-18618970 Sao Paulo, BrazilFAPESP: 2011/01425-0FAPESP: 2012/02229-

Studies of low-lying triplet states in 1,3-C4F6, c-C4F6 and 2-C4F6 by electron energy-loss spectroscopy and ab initio calculations

International audienceThis Letter reports on the first measurements of the lowest lying triplet states as studied by electron energy loss spectroscopy for C4F6 isomers, hexafluoro-1,3-butadiene (1,3-C4F6), hexafluorocyclobutene (c-C4F6) and hexafluoro-2-butyne (2-C4F6). This study has been performed at an incident electron energy of 30 eV, 30°, whilst sweeping the energy loss over the range 2.0-15.0 eV. The electronic state spectroscopy has been investigated and the assignments supported by multi-reference quantum chemical calculations. The transition to the steepest electronic excited potential energy curve, is suggested to be dominant for 2-C4F6, due to the large broadening in its energy profile