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Biomedical subjects

S Inagaki

Publications and source records attributed to S Inagaki.

At least 19 recordsLinked to original sources

Slow transition of energy transport in high-temperature plasmas.

A new slow transition process for energy transport in magnetically confined plasmas is reported. The slow transition is characterized by the change between two metastable transport conditions characterized by a weak and a strong electron temperature (Te) dependence of normalized heat flux. These two branches are found to merge at the critical gradient. In metastable transport, the derivative of normalized heat flux to the Te gradient, [EQUATION: SEE TEXT], is positive, while it becomes negative during the transition phase. The time for the transition increases as the normalized Te gradient is increased and exceeds the transport time scale characterized by the global energy confinement time.

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[Extensive educational program for high performance medical technologists].

The education system for medical technologists has recently been revolutionized, their educational periods vary from 2 to 9 years, and some already have doctoral degrees. In such a new situation, our faculty thinks that the most important point for new medical technologists is the ability to have a broad view of the clinical fields, especially the view of patients. Special training in bed-side education and a stint in several divisions, such as the surgical operation room, rehabilitation. radiological examination room, pharmacy, central storage room of medical records, and medical informatics, and so on, of the hospital is a powerful tool to obtain a broad view of the various clinical fields and can be essential for developing high performance medical technologists. As nine years have passed since starting this education, we evaluated this practice through systematic personal communication. As a result, it was found to be extremely effective for many reasons such as having a continuous image of the patient when they examine the blood sample in the hospital laboratory, showing advanced laboratory performance, and having no mental barrier to visiting the wards and so on. The abilities of our alumni are praised highly by many large scale hospitals around the country and 50% of them are working in the clinical laboratory division of these hospitals. About 40% are working in the division of research and development in various companies. We express sincere thanks to the director and all cooperative individuals for this course in the Osaka University Hospital.

Curriculum↗

Synergy between Tannerella forsythia and Fusobacterium nucleatum in biofilm formation.

During dental plaque formation, the interaction of different organisms is important in the development of complex communities. Fusobacterium nucleatum is considered a 'bridge-organism' that facilitates colonization of other bacteria by coaggregation-mediated mechanisms and possibly by making the environment conducive for oxygen intolerant anaerobes. These studies were carried out to determine whether coaggregation between F. nucleatum and Tannerella forsythia is important in the formation of mixed species biofilms. Further, the role of BspA protein, a surface adhesin of T. forsythia, in coaggregation and biofilm formation was investigated. The results showed the development of synergistic mixed biofilms of F. nucleatum and T. forsythia when these bacteria were cocultured. The BspA protein was not involved in biofilm formation. Though BspA plays a role in coaggregation with F. nucleatum, presumably other adhesins are also involved. The synergistic biofilm formation between the two species was dependent on cell-cell contact and soluble components of the bacteria were not required. This study demonstrates that there is a positive synergy between F. nucleatum and T. forsythia in the development of mixed biofilms and that the cell-cell interaction is essential for this phenomenon.

Adhesins, Bacterial↗

Tannerella forsythia-induced alveolar bone loss in mice involves leucine-rich-repeat BspA protein.

Tannerella forsythia (formerly Bacteroides forsythus) is one of the periodontal pathogens recently implicated in the development of periodontal disease. The cell-surface-associated, as well as the secreted, leucine-rich-repeat protein (BspA) of this bacterium have been suggested to play roles in bacterial adherence, and also in inflammation, by triggering release of pro-inflammatory cytokines from monocytes and chemokines from osteoblasts, leading to inflammation and bone resorption. In this study, we sought to determine the pathogenic potential of T. forsythia and the in vivo role of the BspA protein in pathogenesis in the mouse model of infection-induced alveolar bone loss. The results showed alveolar bone loss in mice infected with the T. forsythia wild-type strain, whereas the BspA mutant was impaired. In conclusion, evidence is presented in support of T. forsythia as an important organism involved in inducing alveolar bone loss, and the BspA protein is an important virulence factor of this bacterium.

Alveolar Bone Loss↗

Observation of reduced heat transport inside the magnetic island O point in the large helical device.

Evidence for a reduction of heat transport inside the magnetic island O point is observed from the propagation of a cold pulse produced by a tracer encapsulated solid pellet in the Large Helical Device. A small peak and slow propagation of the cold pulse are observed inside the island. A significant result is that electron heat diffusivity inside the island is estimated to be 0.2 m(2)/s which is smaller than that outside the island by an order of magnitude.

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Sawtooth oscillation in current-carrying plasma in the large helical device.

Sawtooth oscillations have been observed in current-carrying helical plasmas by using electron-cyclotron-emission diagnostics in the Large Helical Device. The plasma current, which is driven by neutral beam injection, reduces the beta threshold of the sawtooth oscillation. When the central q value is increased due to the plasma current, the core region crashes, and, when it is decreased, the edge region crashes annularly. Observed rapid mixture of the plasma in the limited region suggests that these sawtooth crashes are reconnection phenomena. Unlike previous experiments, no precursor oscillation has been observed.

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Island dynamics in the large-helical-device plasmas.

In the Large Helical Device plasma discharges, the size of an externally imposed island with mode number ( n/m = 1/1) decreases substantially when the plasma is collisionless ( nu(*)< approximately 1) and the beta is finite ( > approximately 0.1%) at the island location. For the collisional plasmas with finite beta, on the other hand, the size of the island increases. However, there is a threshold in terms of the vacuum island size below which the island enlargement is not seen.

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Observation of plasma flow at the magnetic island in the large helical device.

Radial profiles of ion temperature and plasma flow are measured at the n/m = 1/1 magnetic island produced by external perturbation coils in the Large Helical Device. The sheared poloidal flows and sheared radial electric field are observed at the boundaries of the magnetic island, because the poloidal flow vanishes inside the static magnetic island. When the width of the magnetic island becomes large, the flow along the magnetic flux surface inside the magnetic island appears around the O point in the direction which reduces the shear of the poloidal flow at the boundary of the magnetic island.

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Structural features of aliphatic N-nitrosamines of 7-azabicyclo[2.2.1]heptanes that facilitate N-NO bond cleavage.

N-Nitrosamines can be considered as potential nitric oxide (NO)/nitrosonium ion (NO(+)) donors. However, the relation of the structures of N-nitrosamines, in particular of aliphatic N-nitrosamines, to the characteristics of release of NO or NO(+) remains unclear. Here we show that aliphatic N-nitrosoamines of 7-azabicyclo[2.2.1]heptanes can undergo heterolytic N-NO bond cleavage. On the basis of the observation of reduced rotational barriers of the N-NO bonds in solution and nitrogen-pyramidal structures of the N-nitroso group in the solid state, we postulate that N-NO bond cleavage of N-nitrosamines is enhanced by a reduction of the resonance in the N-NO group. Computational studies suggest that these structural features of the N-nitrosamines of 7-azabicyclo[2.2.1]heptane are derived from angle strain imposed on the CNC angles.

Bridged Bicyclo Compounds, Heterocyclic↗

Observation of the "self-healing" of an error field island in the large helical device.

It was observed that the vacuum magnetic island produced by an external error magnetic field in the large helical device shrank in the presence of plasma. This was evidenced by the disappearance of flat regions in the electron temperature profile obtained by Thomson scattering. This island behavior depended on the magnetic configuration in which the plasmas were produced.

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Oxidative transformation of arylmethyl bromides and alcohols with a combination of mesoporous silica FSM-16 and alkali iodides under photoirradiation.

[reaction: see text]. A mesoporous silica FSM-16 was found to be a selective and recyclable promoter for the oxidative dehalogenation of arylmethyl bromides to provide the corresponding alcohols and for the oxidation of arylmethyl alcohols to provide the corresponding aldehydes with a combination of alkali iodides and solvents under photoirradiation conditions.

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Reduction of ion thermal diffusivity associated with the transition of the radial electric field in neutral-beam-heated plasmas in the large helical device.

Recent large helical device experiments revealed that the transition from ion root to electron root occurred for the first time in neutral-beam-heated discharges, where no nonthermal electrons exist. The measured values of the radial electric field were found to be in qualitative agreement with those estimated by neoclassical theory. A clear reduction of ion thermal diffusivity was observed after the mode transition from ion root to electron root as predicted by neoclassical theory when the neoclassical ion loss is more dominant than the anomalous ion loss.

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Helium-4 Bose fluids formed in one-dimensional 18 A diameter pores.

Bose fluids restricted in one dimension (1D) are realized by adsorbing 4He atoms on the 1D pore walls with a diameter of about 18 A. The Bose fluid appears above an adsorbed amount after the pore walls are coated with the inert 4He atoms. Heat capacity of the fluid was observed to have a temperature-linear term at low temperatures. This corresponds to the phonon heat capacity of the Bose fluid in the 1D pores. We estimate the phonon velocity and the interaction of the 1D Bose fluid.

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Separation of signal and noise from in vivo optical recording in Guinea pigs using independent component analysis.

Optical recording in vivo severely suffers from the interference of heartbeat noise. So far, heartbeat noise has been minimized by subtracting from each experimental trial an average of interlaced control recordings. This method, however, is time-consuming and increases tissue damage due to phototoxicity. Here we applied independent component analysis (ICA) to in vivo optical recordings, for separation of auditory signals and noises. Our results show that ICA can be successfully used to separate sound-evoked signals and heartbeat noises. Compared with the previous method, ICA has a comparable power of separation and does not require background recordings.

Acoustic Stimulation↗

Unusually short distances between the carbonyl oxygen and the tin atom in RCOSMR'3 (M = Ge, Sn, Pb): the importance of intramolecular n(O) --> sigma*(MS) orbital interactions.

[structure: see text]. We found that the C=O.Sn distance in RCOSSnR'3 was shorter than the C=O.Ge distance in RCOSGeR'3 and theoretically confirmed that the orbital interactions between the nonbonding orbitals on the carbonyl oxygen (n(O)) and the sigma*(SnS) orbitals were important in regard to the shortness.

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Characterization and photocatalytic reduction of CO2 with H2O on Ti/FSM-16 synthesized by various preparation methods.

Ti/FSM-16 photocatalysts were prepared by various methods and their reactivity for the photocatalytic reduction of CO2 with H2O at 323 K was investigated. UV irradiation of Ti/FSM-16 in the presence of CO2 and H2O led to the formation of CH4 and CH3OH. The photocatalytic reactivity and selectivity differed remarkably by variations in the preparation method. Analyses of the UV-Vis absorption and XAFS spectra showed that the dispersion and local structure of the Ti-oxide species greatly depended on the preparation method. The formation of CH3OH was found to be related to the local structure of the Ti-oxide species while the yield of the photoluminescence was attributed to the charge transfer excited state of the highly dispersed tetrahedrally coordinated Ti-oxide species. Methanol formation was found to be more efficient on Ti/FSM-16 having such highly dispersed tetrahedrally coordinated Ti-oxide species.

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