Supragingival plaque is permanently in contact with saliva. However, the extent to which the microbiota contributes to the salivary bacterial population remains unclear. We compared the compositional shift in the salivary bacterial population with that in supragingival plaque following periodontal therapy. Samples were collected from 19 patients with periodontitis before and after periodontal therapy (mean sample collection interval, 25.8±2.6 months), and their bacterial composition was investigated using barcoded pyrosequencing analysis of the 16S rRNA gene. Phylogenetic community analysis using the UniFrac distance metric revealed that the overall bacterial community composition of saliva is distinct from that of supragingival plaque, both pre- and post-therapy. Temporal variation following therapy in the salivary bacterial population was significantly smaller than in the plaque microbiota, and the post-therapy saliva sample was significantly more similar to that pre-therapy from the same individual than to those from other subjects. Following periodontal therapy, microbial richness and biodiversity were significantly decreased in the plaque microbiota, but not in the salivary bacterial population. The operational taxonomic units whose relative abundances changed significantly after therapy were not common to the two microbiotae. These results reveal the compositional stability of salivary bacterial populations against shifts in the supragingival microbiota, suggesting that the effect of the supragingival plaque microbiota on salivary bacterial population composition is limited.

These findings suggest that an autocrine mechanism of RANKL-RANK exists in osteoclast, which is heightened in the pathological conditions. Furthermore, the autocrine mechanism of IL-1beta and TNFalpha is also provided in osteoclast under pathological condition. These autocrine mechanisms therefore seem to regulate the osteoclast function in both physiological and pathological conditions.

Using one of the world most powerful laser facility, we demonstrate for the first time that high-contrast multi-picosecond pulses are advantageous for proton acceleration. By extending the pulse duration from 1.5 to 6 ps with fixed laser intensity of 1018 W cm−2, the maximum proton energy is improved more than twice (from 13 to 33 MeV). At the same time, laser-energy conversion efficiency into the MeV protons is enhanced with an order of magnitude, achieving 5% for protons above 6 MeV with the 6 ps pulse duration. The proton energies observed are discussed using a plasma expansion model newly developed that takes the electron temperature evolution beyond the ponderomotive energy in the over picoseconds interaction into account. The present results are quite encouraging for realizing ion-driven fast ignition and novel ion beamlines.

A kilo-tesla level, quasi-static magnetic field (B-field), which is generated with an intense laser-driven capacitor-coil target, was measured by proton deflectometry with a proper plasma shielding. Proton deflectometry is a direct and reliable method to diagnose strong, mm3-scale laser-produced B-field; however, this was not successful in the previous experiment. A target-normal-sheath-accelerated proton beam is deflected by Lorentz force in the laser-produced magnetic field with the resulting deflection pattern recorded on a radiochromic film stack. A 610 ± 30 T of B-field amplitude was inferred by comparing the experimental proton pattern with Monte-Carlo calculations. The amplitude and temporal evolutions of the laser-generated B-field were also measured by a differential magnetic probe, independently confirming the proton deflectometry measurement results.

Matsumoto, T.; Minamihata, T.; Sawai, K.; Matsuo, K.; Mima, K.; Nishihara, K.; Azechi, H.; Tanaka, K.A.; Takabe, H.; Nakai, S. Citation Physical Review Letters. 68(1) P.

Fast isochoric heating of a pre-compressed plasma core with a high-intensity short-pulse laser is an attractive and alternative approach to create ultra-high-energy-density states like those found in inertial confinement fusion (ICF) ignition sparks. Laser-produced relativistic electron beam (REB) deposits a part of kinetic energy in the core, and then the heated region becomes the hot spark to trigger the ignition. However, due to the inherent large angular spread of the produced REB, only a small portion of the REB collides with the core. Here, we demonstrate a factor-of-two enhancement of laser-to-core energy coupling with the magnetized fast isochoric heating. The method employs a magnetic field of hundreds of Tesla that is applied to the transport region from the REB generation zone to the core which results in guiding the REB along the magnetic field lines to the core. This scheme may provide more efficient energy coupling compared to the conventional ICF scheme.

A comparison of national surveys on oral health suggested that the population of South Korea has a better periodontal health status than that of Japan, despite their similar inherent backgrounds. Here, we investigated differences in oral bacterial assemblages between individuals from those two countries. To exclude potential effects of oral health condition on the microbiota, we selected 52 Korean and 88 Japanese orally healthy adults (aged 40–79 years) from the participants of two cohort studies, the Yangpyeong study in South Korea and the Hisayama study in Japan, and compared the salivary microbiomes. The microbiota of the Japanese individuals comprised a more diverse community, with greater proportions of 17 bacterial genera, including Veillonella, Prevotella, and Fusobacterium, compared to the microbiota of the Korean individuals. Conversely, Neisseria and Haemophilus species were present in much lower proportions in the microbiota of the Japanese individuals than the Korean individuals. Because higher proportions of Prevotella and Veillonella and lower proportions of Neisseria and Haemophilus in the salivary microbiome were implicated in periodontitis, the results of this study suggest that the greater proportion of dysbiotic oral microbiota in the Japanese individuals is associated with their higher susceptibility to periodontitis compared to the Korean individuals.

for an Invited Paper for the DPP15 Meeting of the American Physical SocietyWe report on progresses of the Fast Ignition Realization Experiment (FIREX) project that has been curried out at the Institute of Laser Engineering to assess the feasibility of high density core heating with a high-power, short-pulse laser including the construction of the Kilo-Joule, Petawatt class LFEX laser system. Our recent studies identify three scientific challenges to achieve high heating efficiency in the fast ignition (FI) scheme with the current GEKKO and LFEX laser systems: (i) control of energy distribution of relativistic electron beam (REB), (ii) guiding and focusing of REB to a fuel core, and (iii) formation of a high areal-density core. The control of the electron energy distribution has been experimentally confirmed by improving the intensity contrast of the LFEX laser up to >10 9 and an ultra-high contrast of 10 11 with a plasma mirror. After the contrast improvement, 50% of the total REB energy is carried by a low energy component of the REB, which slope temperature is close to the ponderomotive scaling value (∼ 1 MeV). To guide the electron beam, we apply strong external magnetic field to the REB transport region. Guiding of the REB by 0.6 kT field in a planar geometry has already been demonstrated at LULI 2000 laser facility in a collaborative experiment lead by CELIA-Univ. Bordeaux. Considering more realistic FI scenario, we have performed a similar experiment using the Kilo-Joule LFEX laser to study the effect of guiding and magnetic mirror on the electron beam. A high density core of a laser-imploded 200 µm-diameter solid CD ball was radiographed with picosecond LFEX-produced K-alpha backlighter. Comparisons of the experimental results and integrated simulations using hydrodynamic and electron transport codes suggest that 10% of the efficiency can be achievable with the current GEKKO and LFEX laser system with the success of the above challenges.