On the IMF Multiplicity in Au+Au Reactions

Intermediate mass fragment (IMF) multiplicity has been investigated for Au+Au reactions at incident energies of 100, 250 and 400 MeV/A. From the analysis of the impact-parameter-dependence of the IMF multiplicity using our QMD plus statistical evaporation model, we found that 1) statistical decay process modifies the results greatly, and 2) the Fermi motion plays a role to increase the IMF multiplicity for whole impact-parameter range.Comment: 9pages, Latex is used, 2 Postscript figures are available by request from [email protected]

Relativistic Effects in the Transverse Flow in the Molecular Dynamics Framework

In order to investigate relativistic effects we compare the transverse flow calculated by using the four versions of the QMD approaches with that of the full covariant RQMD approach. From the comparison we conclude that the simplified RQMD (RQMD/S), which uses the common time coordinate to all particles, can be used instead of RQMD up to 6 GeV/u.Comment: 6pages, Latex is used, 1 Postscript figures are available by request from [email protected]

Development of Alkali Metal-Embedded Nanoporous Carbon Nitride and Elucidation of its Solid Basicity

学位の種別: 課程博士審査委員会委員 : （主査）東京大学教授 尾中 篤, 東京大学教授 村田 滋, 東京大学教授 平岡 秀一, 東京大学教授 寺尾 潤, 東京大学准教授 内田 さやかUniversity of Tokyo(東京大学

Enterococcus faecium WB2000 Inhibits Biofilm Formation by Oral Cariogenic Streptococci

This study investigated the inhibitory effect of probiotic Enterococcus faecium WB2000 on biofilm formation by cariogenic streptococci. The ability of E. faecium WB2000 and JCM5804 and Enterococcus faecalis JCM5803 to inhibit biofilm formation by seven laboratory oral streptococcal strains and 13 clinical mutans streptococcal strains was assayed. The Enterococcal strains inhibited biofilm formation in dual cultures with the mutans streptococcal strains Streptococcus mutans Xc and Streptococcus sobrinus JCM5176 (P < 0.05), but not with the noncariogenic streptococcal strains. Enterococcus faecium WB2000 inhibited biofilm formation by 90.0% (9/10) of the clinical S. mutans strains and 100% (3/3) of the clinical S. sobrinus strains. After culturing, the pH did not differ between single and dual cultures. The viable counts of floating mutans streptococci were lower in dual cultures with E. faecium WB2000 than in single cultures. Enterococcus faecium WB2000 acted as a probiotic bacterial inhibitor of cariogenic streptococcal biofilm formation

Effect of S-PRG Eluate on Biofilm Formation and Enzyme Activity of Oral Bacteria

Recently, the antibacterial activity of a composite resin containing prereacted glass ionomer (S-PRG) filler was revealed. We examined the effect of an S-PRG eluate on various biologic activities of Streptococcus mutans and Porphyromonas gingivalis. Adherence ability of S. mutans was evaluated by microtiter plate assay; protease and gelatinase activities of P. gingivalis were examined by synthetic substrate hydrolysis and gelatin film spot assay, respectively. Coaggregation of P. gingivalis with Fusobacterium nucleatum was also examined. S-PRG eluate was found to suppress streptococcal adherence. S-PRG eluate inhibited the protease and gelatinase activities of P. gingivalis and the coaggregation between P. gingivalis and F. nucleatum. These results indicate that S-PRG eluate suppresses streptococcal adherence and inhibits the protease and coaggregation activities of P. gingivalis. These findings may prompt research into novel strategies for preventing caries and periodontitis

Analysis of proton-induced fragment production cross sections by the Quantum Molecular Dynamics plus Statistical Decay Model

The production cross sections of various fragments from proton-induced reactions on $^{56}$Fe and $^{27}$Al have been analyzed by the Quantum Molecular Dynamics (QMD) plus Statistical Decay Model (SDM). It was found that the mass and charge distributions calculated with and without the statistical decay have very different shapes. These results also depend strongly on the impact parameter, showing an importance of the dynamical treatment as realized by the QMD approach. The calculated results were compared with experimental data in the energy region from 50 MeV to 5 GeV. The QMD+SDM calculation could reproduce the production cross sections of the light clusters and intermediate-mass to heavy fragments in a good accuracy. The production cross section of $^{7}$Be was, however, underpredicted by approximately 2 orders of magnitude, showing the necessity of another reaction mechanism not taken into account in the present model.Comment: 12 pages, Latex is used, 6 Postscript figures are available by request from [email protected]

A Case Report of Tooth Wear Associated with a Patient's Inappropriate Efforts to Reduce Oral Malodor Caused by Endodontic Lesion

Here, we report a case of severe tooth wear associated with a patient's inappropriate efforts to reduce oral malodor. A 72-year-old male patient visited our breath clinic complaining of strong breath odor. Former dentists had performed periodontal treatments including scaling and root planing, but his oral malodor did not decrease. His own subsequent breath odor-reducing efforts included daily use of lemons and vinegar to reduce or mask the odor, eating and chewing hard foods to clean his teeth, and extensive tooth brushing with a hard-bristled toothbrush. Oral malodor was detected in our breath clinic by several tests, including an organoleptic test, portable sulphide monitor, and gas chromatography. Although patient's oral hygiene and periodontal condition were not poor on presentation, his teeth showed heavy wear and hypersensitiving with an unfitted restoration on tooth 16. Radiographic examination of the tooth did not reveal endodontic lesion, but when the metal crown was removed, severe pus discharge and strong malodor were observed. When this was treated, his breath odor was improved. After dental treatment and oral hygiene instruction, no further tooth wear was observed; he was not concerned about breath odor thereafter

Bone cancer induces a unique central sensitization through synaptic changes in a wide area of the spinal cord

<p>Abstract</p> <p>Background</p> <p>Chronic bone cancer pain is thought to be partly due to central sensitization. Although murine models of bone cancer pain revealed significant neurochemical changes in the spinal cord, it is not known whether this produces functional alterations in spinal sensory synaptic transmission. In this study, we examined excitatory synaptic responses evoked in substantia gelatinosa (SG, lamina II) neurons in spinal cord slices of adult mice bearing bone cancer, using whole-cell voltage-clamp recording techniques.</p> <p>Results</p> <p>Mice at 14 to 21 days after sarcoma implantation into the femur exhibited hyperalgesia to mechanical stimuli applied to the skin of the ipsilateral hind paw, as well as showing spontaneous and movement evoked pain-related behaviors. SG neurons exhibited spontaneous excitatory postsynaptic currents (EPSCs). The amplitudes of spontaneous EPSCs were significantly larger in cancer-bearing than control mice without any changes in passive membrane properties of SG neurons. In the presence of TTX, the amplitude of miniature EPSCs in SG neurons was increased in cancer-bearing mice and this was observed for cells sampled across a wide range of lumbar segmental levels. Alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor- and <it>N</it>-methyl-<it>D</it>-aspartate (NMDA) receptor-mediated EPSCs evoked by focal stimulation were also enhanced in cancer-bearing mice. Dorsal root stimulation elicited mono- and/or polysynaptic EPSCs that were caused by the activation of Aδ and/or C afferent fibers in SG neurons from both groups of animals. The number of cells receiving monosynaptic inputs from Aδ and C fibers was not different between the two groups. However, the amplitude of the monosynaptic C fiber-evoked EPSCs and the number of SG neurons receiving polysynaptic inputs from Aδ and C fibers were increased in cancer-bearing mice.</p> <p>Conclusions</p> <p>These results show that spinal synaptic transmission mediated through Aδ and C fibers is enhanced in the SG across a wide area of lumbar levels following sarcoma implantation in the femur. This widespread spinal sensitization may be one of the underlying mechanisms for the development of chronic bone cancer pain.</p