Effect of periodontitis induced by Fusobacterium nucleatum on the microbiota of the gut and surrounding organs.

Detection of the oral bacterium Fusobacterium nucleatum in colorectal cancer tissues suggests that periodontitis may alter gut microbiota. The purpose of this study was to analyze the influence and infection route of periodontal inflammation caused by F. nucleatum, and microbiota of the gut and surrounding organs (heart, liver, kidney). Wistar female rats were orally inoculated with F. nucleatum to establish an experimental periodontitis model that was confirmed by X-ray imaging and histopathological analysis. The mandibles, gut, liver, heart, and kidneys were collected from the experimental group at 2, 4, and 8 weeks, and from the uninfected control group at 0 weeks, for DNA extraction for PCR amplification and comprehensive microbiota analysis using the Illumina MiSeq platform. Imaging confirmed the onset of periodontitis at 2 weeks post-inoculation, and histopathology showed inflammatory cell infiltration from 2 to 8 weeks. PCR and comprehensive microbiota analysis showed the presence of F. nucleatum in the heart and liver at 2 weeks, and in the liver at 4 and 8 weeks. There were changes of microbiota of the gut, heart, liver, and kidneys at 4 weeks: namely, decreased Verrucomicrobia and Bacteroidetes, and increased Firmicutes. F. nucleatum induced the onset of periodontitis and infected the heart and liver in rats. As the periodontic lesion progressed, the microbiota of the gut, liver, heart, and kidneys were altered.

Evaluation of the biocompatibility of resin-based root canal sealers in rat periapical tissue.

We evaluated the biocompatibility of resin-based root canal sealers (RCSs) in the periapical tissues of rats. Wistar rats underwent tooth replantation for reproducing the response of periapical tissue with RCSs. The resin-based Epipany SE, AH Plus Jet, the eugenol-based sealer (Canals) and a control group were employed. The upper right first molar was extracted and applied with RCSs on apices, and then the tooth was repositioned. Histological evaluation demonstrated that mild inflammation occurred in the periapical tissue with Epiphany and AH Plus Jet sealers on day 7, whereas Canals induced severe-to-moderate inflammation. The statistical analyses demonstrated that the significant differences were observed between Canals and the other groups on day 7 regarding inflammatory response. On day 14, the lesions induced by all sealers were healed and replaced predominantly by fibrous connective tissue. Our results suggest that Epiphany SE and AH Plus Jet are good biocompatible materials.

A new interpretation method of surface wave measurements to obtain representative shear wave velocity profiles of soils

This paper presents the reference profile concept and shows that it fits well with measured CXW data. Reference SWV profiles may be obtained in the field almost immediately following the measurements and may be used as representative profiles for site amplification evaluations eliminating the need for computationally intensive inversion solutions used with other Vf-Vs methods.(AU)

Non - intrusive surface waves measurements for shear wave velocity profiling of liquefiable sites

Accurate shear wave velocity profiles have been long recognized as essential data to evaluate the dynamic response of soil deposits for analysis of liquefaction potential, site amplification, and soil-structure interaction under earthquake and other forms of dynamic loading. The determination of shear wave velocity profiles is especially important for numerical models used in earthquake-resistant design of lifeline facilities and for assessment of the effectiveness of remediation measures in liquefiable sites.(AU)

Local site effects on weak and strong ground motions at the Ashigara Valley, Japan

In this paper, two main issues are studied using weak and strong motions observed at a vertical array in the Ashigara Valley, Japan. One is identification of body waves and surface waves. The other is the emergence of nonlinearity of soil. We found that in a short period range in the later phases of observed seismograms, vertically propagating S waves are predominant but surface waves are not. We interpret the phenomena that surface waves in a short period range may disappear due to low Q value in the soft sedimentary deposits. It is also found that the main part of the strong motion, whose maximum acceleration is 200 gal and whose duration is 3 sec, has the potential of making the surface soil nonlinear with the order of ... effective shear strain in the soft surface soil, but that the soil returns to the linear range in the part just after the main part (AU)