Regulatory Systems for Prevention and Control of Rabies, Japan

Japan’s systems provide an effective model for elimination of rabies worldwide

Polarized Raman analysis of the molecular rearrangement and residual strain on the surface of retrieved polyethylene tibial plates

The response to applied strain of EtO-sterilized and gamma-irradiated polyethylene materials belonging to tibial inserts has been studied by polarized Raman spectroscopy. Initial calibrations on as-received samples from three different makers were employed to clarify the rearrangement of molecular chains under strain, expressed in terms of Euler angular displacements in space and orientation distribution functions. This body of information was then applied to a quantitative analysis of four tibial inserts (from the same three makers of the unused samples) retrieved after in vivo exposures ranging between 7 months and 5 years 8 months. The main results of the Raman analysis can be summarized as follows: (i) gamma-irradiated samples experienced lower texturing on the molecular scale compared to EtO-sterilized samples, likely due to a higher strain recovery capability; and (ii) independent of sterilization method, the amount of plastic strain was mainly developed early after in vivo implantation, whereby out-of-plane molecules rotated under load onto planes parallel to the sample surface until saturation of angular displacements was reached. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved

Raman spectroscopic study of remelting and annealing-induced effects on microstructure and compressive deformation behavior of highly crosslinked UHMWPE for total hip arthroplasty

Three-dimensional crystallographic morphologies were studied by means of confocal/polarized Raman spectroscopy as developed upon manufacturing in three different types of first and second generation highly crosslinked UHMWPE (HXLPE) acetabular liners. The impact of such microstructural characteristics on the deformation behavior of the liners was also evaluated and discussed from the viewpoint of molecular chain mobility. All the investigated liners showed similar microstructural transitions within the first 35 mu pm below their surfaces in terms of crystallinity, molecular orientation, and crystalline anisotropy. Interestingly, different postirradiation heat treatments (remelting or annealing in single step or in sequential steps) led to clear differences in the subsurface microstructure among the three liners. Remelted liner possessed both lower bulk crystallinity and degree of molecular orientation as compared to the annealed liners. Sequentially, irradiated/annealed liner showed the highest degree of crystallinity and orientation among the studied liners. The peculiar microstructure of this latter liner exhibited the highest restoring (shape-recovery) force against the applied uniaxial strain. Accordingly, the present study suggests that the sequential irradiation and annealing offers an efficient way to obtain microstructure quite suitable for attaining high creep resistance. However, all the investigated liners exhibited the significantly low values of surface anisotropy, which could be equally efficient in minimizing strain-softening-assisted wear phenomena. (C) 2014 Wiley Periodicals, Inc

Activation of PPARγ inhibits cell growth and induces apoptosis in human gastric cancer cells

AbstractWe investigated the expression of peroxisome proliferator-activated receptor γ (PPARγ) and the role of PPARγ in cell growth in human gastric cancer cells. Reverse transcription-polymerase chain reaction, Northern blot and Western blot analyses showed that a human gastric cancer cell line, MKN45, expressed PPARγ mRNA and protein. Luciferase assay in MKN45 cells showed that troglitazone, a selective ligand for PPARγ, transactivated the transcription of a peroxisome proliferator response element-driven promoter. Troglitazone or pioglitazone, selective ligands for PPARγ, inhibited the growth of MKN45 cells in a dose-dependent manner. Co-incubation of MKN45 cells with troglitazone induced DNA ladder formation. These results suggest that human gastric cancer cells express PPARγ and that activation of PPARγ inhibits cell growth and induces apoptosis in gastric cancer cells

In situ measurements of local temperature and contact stress magnitude during wear of ceramic-on-ceramic hip joints

Fluorescence microprobe spectroscopy was applied to in situ assessments of contact stress and local temperature at the contact point of dry-sliding couples during wear tests of two commercially available ceramic-on-ceramic femoral heads. The investigated ceramic hip implants consisted of either monolithic Al2O3 or Al2O3/ZrO2 composite. A specially designed pin-on-ball tribometer was employed, which enabled directly testing the femoral head components as received from the maker without further manipulation. The strong fluorescence emission from Cr3+ impurities contained in Al2O3 served as a responsive sensor for both temperature and stress. Analytical corrections for the averaging effects arising from the finite size of the laser probe were made according to a probe response formalism in which geometrical conditions of the sliding couple were incorporated as boundary conditions. The sample-probe interaction at the contact point was then experimentally calibrated by obtaining probe response functions for the two materials investigated. Based on such theoretical and experimental procedures, deconvolutive computational routines could be set up and the true variations of local temperature and stress at the contact point of the bearing surfaces retrieved from the observed time-dependent broadening and shift of a selected spectral band, respectively. The main result of the in situ investigation was that the monolithic sliding couple showed both significantly lower temperature and lower magnitude of compressive stress at the contact point as compared to the composite one, although the composite couple wore at a significantly lower specific wear rate than the monolithic one. (C) 2013 Elsevier Ltd. All rights reserved

Disentangling the migration phases during the non-breeding period reveals uneven carry-over effects to the subsequent breeding in a diving seabird

第6回極域科学シンポジウム[OB] 極域生物圏11月16日（月）　統計数理研究所 セミナー室1（D305

Non-destructively differentiating the roles of creep, wear and oxidation in long-term in vivo exposed polyethylene cups

Wear of polyethylene acetabular cups in patients of total hip arthroplasty is routinely deduced from the penetration of the femoral head into the acetabular liner as observed in the radiographs. However, the linear penetration thus measured represents the cumulative contribution of two components, one due to wear, and the other due to creep or irreversible deformation of the polyethylene structure. The erroneous attribution to wear of the entire penetration displacement of the head in the cup might lead to misinterpretation of the actual performance of acetabular cups. The aim of this study was to quantify the head displacement components due to wear and to creep, as they occur in vivo in acetabular cups, and to relate them to the oxidation state of the material by means of advanced Raman spectroscopy procedures. Throughout the investigation, we compared the behaviors on the molecular scale of acetabular cups subjected to different sterilization methods (i.e., gamma-irradiation and ethylene oxide treatment). (C) Koninklijke Brill NV, Leiden, 201

Denitrification in low oxic environments increases the accumulation of nitrogen oxide intermediates and modulates the evolutionary potential of microbial populations.

Denitrification in oxic environments occurs when a microorganism uses nitrogen oxides as terminal electron acceptors even though oxygen is available. While this phenomenon is well-established, its consequences on ecological and evolutionary processes remain poorly understood. We hypothesize here that denitrification in oxic environments can modify the accumulation profiles of nitrogen oxide intermediates with cascading effects on the evolutionary potentials of denitrifying microorganisms. To test this, we performed laboratory experiments with Paracoccus denitrificans and complemented them with individual-based computational modelling. We found that denitrification in low oxic environments significantly increases the accumulation of nitrite and nitric oxide. We further found that the increased accumulation of these intermediates has a negative effect on growth at low pH. Finally, we found that the increased negative effect at low pH increases the number of individuals that contribute to surface-associated growth. This increases the amount of genetic diversity that is preserved from the initial population, thus increasing the number of genetic targets for natural selection to act upon and resulting in higher evolutionary potentials. Together, our data highlight that denitrification in low oxic environments can affect the ecological processes and evolutionary potentials of denitrifying microorganisms by modifying the accumulation of nitrogen oxide intermediates