Chapter 4 : Injury and the Recovery Reaction due to the Penetration of Material into the Mandibular Canal

A root canal filling material paste, mainly made of calcium hydroxide and iodoform with the addition of silicone oil, was experimentally introduced into the mandibular canals of dogs. The tissue reactions to the paste were examined by radiography, histopathology, and electron microscopy. The examination results showed that the paste was phagocytosed by macrophages and, in general, was gradually resorbed by the passage of time. The paste was also found to cause heterotopic calcification and/or bone formation within the limited area of original penetration. The histopathological tissue changes of the alveolar nerve tissue were also examined. No injury-related histopathological change was observed as long as the injected paste did not contact alveolar nerve tissue, but tissue damage was observed at sites of direct contact. After removal of degenerated nerved debris by macrophages and Schwann cells, the persisting external membrane or “Schwann tubes” appeared to provide a scaffold for axonal regeneration and Schwann cell proliferation.Editor, Toshiyuki KawakamiLanguage Editor, David M Carlsonviii, 232 p. ill. (some col.

Axisymmetrical Stress Analysis and Strength of Epoxy-Steel Composite Cylinders under push-off loadings

ABSTRACT Composite parts have been used widely for lightening and strengthening mechanical parts, and it is necessary to know the contact stress distributions at the interfaces of the composites. In this paper, the interface stress distribution in composite cylinders of epoxy and steel under push-off loadings is analyzed using axisymmetrical theory of elasticity as a three -body contact problem. Analogous test was conducted to determine the relationship between the normal stress and the shear stress. Using two stress singularity parameters obtained from the numerical stress analyses and analogous test results, a method for estimating the strength of the composite cylinders was proposed. In the numerical calculations, the effects of the diameter and Young's modulus of the solid cylinders on the interface stress distributions are clarified. It is seen that the normal stress and the sheer stress at the lower edges of the interface increase as Young's modulus of the solid cylinders increases. It is also found seen that the normal stress increases and the sheer stress decreases as the diameter of the solid cylinders increases. The experiments were carried out for measuring the ruptured push-off loadings of the composite cylinders. In the experiments, the effects of the diameter of steel cylinders were examined. It is seen that the push-off strength increases as the diameter of the steel cylinders increases. The numerical results are in fairly good agreements with the experimental results

形態計測のためのメタノール・硝酸セルロースによる組織包埋法

Very recently we developed a new embedding medium, "Shiojirin-E", made chiefly of cellulose nitrate (Kawakami et al. 1995)^&;t;1\u272)>. During the course of its development, we noted that cellulose nitrate would be a very suitable embedding medium for morphometric analysis, especially because of its low and constant rate of contraction. But the highviscosity of this medium resulted in a very slow rate of infiltration. Therefore we sought to develop a new, better histological embedding medium for morphometric analysis based on information on the methanol-cellulose nitrate method by Seki (1937)^. After trial and error, we succeeded in our goal : The composition of the medium is as follows : cellulose nitrate 15.0g, methanol 78.6g, and others 6.4g (total of 100.00g). When the specimens are not so big, we can easily get 3-5 micron-thick sections like paraffin sections with complete non-contractibility. We believe that this new methanol-cellulose nitrate medium will be useful especially for histological morphometrical analysis

Estimating dynamics of fern species richness and assemblages for 30 years in Japan capital and along planning belt of linear motor car from Tokyo to Nagoya

We surveyed species density of ferns in Musashi (Tokyo and Saitama Prefs.), around capital of Japan, and planning belt of Linea express of 250km from Tokyo to Nagoya during 1997-2017, considering with records 30 years (mainly 1960-1980). The species richness (species richness per 10km X 10km) and similarity of species assemblages represented by species overlap were recorded and calculated between them of the past and present. Recent species richness is about half or less and the similarity ranged 0-48% in Musashi and 20-50% in the similarity along the Linea express planning belt.ArticleForestry Research and Engineering: International Journal. 2(2):68-73 (2018)journal articl

An Origin of Complicated Infrared Spectra of Perfluoroalkyl Compounds Involving a Normal Alkyl Group

Perfluoroalkyl (Rf) compounds containing a normal alkyl group often yield highly complicated infrared (IR) spectra especially in the C–F stretching vibration (νC–F) region. To reveal the reason behind this, the IR p-polarized multiple-angle incidence resolution spectrometry (pMAIRS) is employed to measure a monolayer of CF3(CF2)9(CH2)3COOH deposited on a silicon substrate. The compound is known to spontaneously aggregate to form a molecular assembly with the closest packing, in which the molecules are oriented perpendicular to the substrate. The IR pMAIRS spectra apparently prove that the complexity of the νC–F region is due to the normal alkyl part directly connected to the Rf group because the carbons in the Rf group are vibrated as a coupled oscillator, and the oscillation of the alkyl part propagates to the Rf part along the molecular axis

Continuous data assimilation of large eddy simulation by lattice Boltzmann method and local ensemble transform Kalman filter (LBM-LETKF)

We investigate the applicability of the data assimilation (DA) to large eddy simulations (LESs) based on the lattice Boltzmann method (LBM). We carry out the observing system simulation experiment of a two-dimensional (2D) forced isotropic turbulence, and examine the DA accuracy of the nudging and the local ensemble transform Kalman filter (LETKF) with spatially sparse and noisy observation data of flow fields. The advantage of the LETKF is that it does not require computing spatial interpolation and/or an inverse problem between the macroscopic variables (the density and the pressure) and the velocity distribution function of the LBM, while the nudging introduces additional models for them. The numerical experiments with $256\times256$ grids and $10\%$ observation noise in the velocity showed that the root mean square error of the velocity in the LETKF with $8\times 8$ observation points ($\sim 0.1\%$ of the total grids) and 64 ensemble members becomes smaller than the observation noise, while the nudging requires an order of magnitude larger number of observation points to achieve the same accuracy. Another advantage of the LETKF is that it well keeps the amplitude of the energy spectrum, while only the phase error becomes larger with more sparse observation. We also see that a lack of observation data in the LETKF produces a spurious energy injection in high wavenumber regimes, leading to numerical instability. Such numerical instability is known as the catastrophic filter divergence problem, which can be suppressed by increasing the number of ensemble members. From these results, it was shown that the LETKF enables robust and accurate DA for the 2D LBM with sparse and noisy observation data.Comment: 27 pages, 14 figure

Light and Electron Microscopic Studies of Microcalcifications Appearing in Monomorphic Adenomas

Microcalcifications appearing in two cases of monomorphic adenomas were studied histopathologically, electron microscopically, and electron-microanalytically. One case was basal cell adenoma that occurred in a 56-year-old man and the other was canalicular adenoma in a 71-year-old woman. The calcified granules were observed both in the lumina formed by the tumor cells and in the stromal tissues. The surroundings of the granules were stained by alcian blue and showed a sulfur peak by EPMA. These facts suggest that the surroundings contain sulfated glycosaminoglycans and that sulfur has a significant role in the mechanisms of pathological calcification as well as physiological calcification