Analyzing Method of Temporal Brain Activation in fMRI Measurements

In this paper, we propose a method to acquire the temporal changes of activations by combining a slide of the analysis time window and t‐value. An advantage of this method is that it can acquire rough changes of the activated areas even with data having low time resolution. Nine normal subjects participated in the study of the visual oddball paradigm, which consisted of a random series of 30 targets and 30 control stimuli. Here, the subjects were instructed to push a button as the go‐task when a target stimulus occurred. We investigated the activated area in three types of analysis time sections: from stimulus onset to 5 s after the stimulus (time section A; TS‐A); from 5 to 10 s (TS‐B); and from 10 to 15 s (TS‐C). We also investigated the temporal change of the t‐value between go and no‐go responses in blood oxygenation level dependent (BOLD) signals. In this study, we picked up the following eight representative areas corresponding with previous reports: left primary motor area and left somatosensory motor area, supramarginal gyri (SMG), right superior parietal lobule, right inferior frontal gyrus, cerebellum (cerebellar tonsil), and right medial frontal gyrus. Among them, the left primary motor area and left somatosensory motor area showed prominent activation (t > 10) in TS‐A and TS‐B, respectively. Activity at the left supramarginal gyrus decreased gradually with time, and right insula showed constant activation through all time sections. We could see various patterns on temporal activation at different positions in the brain. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

The development of a high functional continuous filtration system for sericite powders

A cake-less continuous filtration equipment has been developed based on an evaluation of inorganic powder slurry characteristics by many kinds of measurement methods, such as a sedimentation test under gravity and a hydrostatic pressure test. We have been developing a high-performance cake-less filtration system in which a condensed inorganic powder slurry layer maintains its fluidity. The development of this novel filtration system has allowed us to cease the scraping operation of the cake as well as to collect the highly condensed slurry more easily. These results clearly show that a new device may be realized for the deposition of highly condensed, fluid slurries. It is confirmed that the concentration of the condensed slurry amounted to 35 vol% while still retaining fluidity. The specifications of our new filtration system and its operation conditions for scale-up can be determined by theoretical methods. There is good potential for successfully collecting high condensation slurry more easily in a multiple filter system.     

The excellent water-solubility of N-[3-(dimethyl-amino)propyl] docosanamide chloride : the most eco-friendly cationic hair conditioning agent

A new hair-conditioning agent, N-[3-(dimethylamino)propyl]docosanamide (APA-22) hydrochloric acid salt (APA-22 HCl), has excellent solubility in water with a solubility limit over 10-times larger than that of other APA hydrochloric salts with shorter alkyl chain lengths. The physicochemical characteristics of APA-22 HCl were studied at 25 degrees C by using equilibrium surface tension (gamma), solubilization of an oil-soluble dye, steady-state fluorescence, and chloride ion selective electrode techniques. The APA-22 HCl salt is considered to form an aggregate at a concentration, C(1), which is about twice the concentration of the solubility limit of APAs with shorter alkyl chains. At a higher concentration, C(2), the aggregates of APA-22 HCl start forming another kind of aggregate, which is able to solubilize oil-soluble materials. That is, C(1) is considered to represent the critical aggregation concentration (cac) and C(2) a morphology transition. In the concentration region between C(1) and C(2) the solutions are seemingly transparent whereas at above C(2) they appear bluish or translucent. Since the Krafft point of APA-22 HCl is 55 degrees C, all the solutions, including the aggregates, are thought to exist in metastable states. Notably, however, these metastable solutions do not change significantly over a few months. The excellent solubility of APA-22 HCl in water is considered to be a result of this unique stepwise aggregation with increasing concentration.     

Energy Transfer Enables 1.53 μm Photoluminescence from Erbium-Doped TiO2 Semiconductor Nanocrystals Synthesized by Ar/O2 Radio-Frequency Thermal Plasma

Highly crystalline, highly luminescent nanopowders of Er³⁺-doped TiO₂ have been successfully synthesized via one-step Ar/O₂ radio-frequency thermal plasma processing. Energy transfer from the TiO₂ host to Er³⁺ activators has been confirmed by combined means of UV-vis, excitation, and photoluminescence spectroscopies. As a consequence, bright photoluminescence at ∼1.53 μm was observed from the nanopowders either by directly exciting the Er³⁺ activator or by exciting the TiO₂ host lattice. A comparative study shows that the nanopowder of the same system made via coprecipitation lacks the energy transfer. The plasma-generated nanopowders may thus find applications in optoelectronic devices.     

Garlic extract and its selected organosulphur constituents promote ileal immune responses ex vivo

The effects of garlic extract and three organosulphur compounds of garlic on intestinal immune responses in mice were investigated. Peyer’s patch (PP) cells were isolated from mice orally administered with garlic extracts or one of three organosulphur compounds (alliin, allicin, diallyl disulphide (DADS)). PP cells isolated from mice that had been orally injected with ethanol extract significantly produced interferon (IFN)-γ and interleukin (IL)-4. IL-2 production in PP cells was significantly reduced by hot-water and ethanol extracts from garlic. PP cells from mice administered with two organosulphur compounds, alliin or DADS (5 mg/kg/day), could produce IL-2, IFN-γ and IL-4, whereas allicin showed moderate activity. The enhancement activity of IL-2 and IFN-γ productions in PP cells by DADS was higher than those obtained by administration of alliin or allicin. Comprehensive analyses of genetic profiles in PP tissue from mice administered with ethanolic extracts, allicin or alliin revealed that oral administration of samples increased 68–144 genes and decreased 50–52 genes by ?1.8-fold. Analyses of clustering profiles of microarrays indicated that ethanol extract and alliin upregulated the expression of IFN-γ. These data showed that garlic and its organosulphur compounds stimulate de novo IFN-γ biosynthesis in PP cells, thereby promoting ileal immune responses.     

Calculation of effective delayed neutron fraction with Monte Carlo perturbation techniques

New methods are proposed to estimate the effective delayed neutron fraction β_eff in Monte Carlo calculations: the eigenvalue methods jointly used with the differential operator sampling and correlated sampling techniques. In particular, the eigenvalue method with the differential operator sampling technique has a distinct feature that it theoretically gives an exact β_eff value. To verify the proposed methods, Monte Carlo calculations are performed for several systems with simple geometry. It is found that the results obtained with the proposed methods agree with the reference deterministic results within sufficiently small statistical uncertainties. The indirect perturbed source effect must be taken into account to estimate an exact β_eff value.     

Development of sample holder for in situ neutron measurement of hydrogen absorbing alloy

We developed a sample holder for in situ measurement of hydrogen absorbing alloy. In order to prevent the hydrogen absorption by vanadium, copper is coated with 2 μm thickness on inner surface of the vanadium holder. The effect of copper coating and the performance of the holder were evaluated by neutron diffraction and PDF profiles. The lattice parameters a and c of La₂Ni₇ with Ce₂Ni₇-type structure were refined as 0.505921(4) and 2.468608(4) nm by Rietveld analysis. The Cu-Cu correlation peak around r = 0.255 nm was not observed in the PDF profile. Thus the holder is useful for in situ measurement of hydrogen absorbing alloy. The diffraction and PDF profiles of La₂Ni₇D_x (0 < x < 10.5) were collected using a deuterium pressure of 3.7 MPa, and the changes of crystal and local structures were clearly observed.     

Structure and physical properties of dried Tetra-PEG gel

We investigated crystal structure, and thermal, swelling, and deformation behaviors of dried tetrafunctional (polyethylene glycol) gel, Tetra-PEG gel, with narrow molecular distribution. Tetra-PEG gel consists of two kinds of symmetrical tetrahedron-like PEG macromonomers with a fixed molecular weight. In spite of network structure with rather small molecular weight between cross-links (M_c) (≈5000), the dried Tetra-PEG gels were found to be capable of crystallization. The crystalline melting temperature (T_m) and the degree of crystallinity (X_c) of dried Tetra-PEG gels obtained by differential scanning calorimetry (DSC) were substantially constant against the polymer volume fraction at preparation (?₀). Furthermore, the corrected elastic modulus (G) of dried Tetra-PEG gels did not depend on ?₀. These experimental results indicate that the there exist negligible entanglements in the dried Tetra-PEG network irrespective of ?₀. In other words, Tetra-PEG gels do not have significant topological inhomogeneities.     

Properties of disturbance waves in vertical annular two-phase flow

Disturbance waves play an important role in interfacial transfer of mass, momentum and energy in annular two-phase flow. In spite of their importance, majority of the experimental data available in literature on disturbance wave properties such as velocity, frequency, wavelength and amplitude are limited to near atmospheric conditions (Azzopardi, B.J., 1997. Drops in annular two-phase flow. International Journal of Multiphase Flow, 23, 1-53). In view of this, air-water annular flow experiments have been conducted at three pressure conditions (1.2, 4.0 and 5.8 bar) in a tubular test section having an inside diameter 9.4 mm. At each pressure condition liquid and gas phase flow rates are varied over a large range so that the effects of density ratio, liquid flow rate and gas flow rate on disturbance wave properties can be studied systematically. A liquid film thickness is measured by two flush mounted ring shaped conductance probes located 38.1 mm apart. Disturbance wave velocity, frequency, amplitude and wavelength are estimated from the liquid film thickness measurements by following the statistical analysis methods. Parametric trends in variations of disturbance wave properties are analyzed using the non-dimensional numbers; liquid phase Reynolds number (Re_f), gas phase Reynolds number (Re_g), Weber number (We) and Strouhal number (Sr). Finally, the existing correlations available for the prediction of disturbance wave velocity and frequency are analyzed and a new, improved correlation is proposed for the prediction of disturbance wave frequency. The new correlation satisfactorily predicted the current data and the data available in literature.     

(Eu-Nb)-codoped TiO2 nanopowders synthesized via Ar/O2 radio frequency thermal plasma oxidation processing: Phase composition and photoluminescence properties through energy transfer

(Eu³⁺-Nb⁵⁺)-codoped TiO₂ nanopowders have been prepared by Ar/O₂ radio frequency (RF) thermal plasma oxidizing liquid precursor mists, with various addition contents of dopants (molar ratio of Eu³⁺:Nb⁵⁺ = 1:1). Characterizations have been performed by the combined studies of XRD, TEM, Raman spectra, UV-vis spectroscopy, and excitation and PL spectra. The plasma-generated nanopowders mainly consist of anatase and rutile polymorphs. Doping Nb⁵⁺ cannot have appreciable influence on Eu³⁺ solubility (0.5 at.%) in the TiO₂ host lattice, but can significantly inhibit the increase of rutile weight fraction for TiO₂. 617 nm PL intensity at 350 nm indirect excitation through energy transfer is considerably weaker than that at 467 nm direct excitation, indicating that a defect state level in the TiO₂ host lattice might be lowered below the excited state of Eu³⁺ by doping Nb⁵⁺, which is conceivable from a relatively large amount of oxygen deficiencies yielded in the TiO₂ host lattice.