Digestion of Ceramide 2-Aminoethylphosphonate,a Sphingolipid from the Jumbo Flying Squid <Emphasis Type="Italic">Dosidicus gigas</Emphasis>, in Mice

Ceramide 2-aminoethylphosphonate (CAEP), a sphingophosphonolipid containing a carbon–phosphorus bond, is frequently found in marine organisms and has a unique triene type of sphingoid base in its structure. CAEP has not been evaluated as a food ingredient, although it is generally contained in Mollusca organisms such as squids and shellfish, which are consumed worldwide. In this study, we aimed to elucidate the effects of CAEP as a food component by evaluating the digestion of CAEP extracted from the skin of the jumbo flying squid Dosidicus gigas. Our results revealed that dietary CAEP was digested to free sphingoid bases via ceramides by the mouse small intestinal mucosa. At pH 7.2, CAEP was hydrolyzed more rapidly than the major mammalian sphingolipid sphingomyelin; however, the hydrolysis of CAEP was similar to that of sphingomyelin at pH 9.0. Thus, the digestion of CAEP may be catalyzed by alkaline spingomyelinase and other enzymes. Our findings provide important insights into the digestion of the dietary sphingophosphonolipid CAEP in marine foods.     

A critical phenomenon of phase transition in hydroxyapatite investigated by thermally stimulated depolarization currents

We observed a critical phenomenon of ferroelectric transition in hydroxyapatite (HAp) through measuring the thermally stimulated depolarization current of polycrystalline monoclinic HAp. Two peaks attributable to hydroxide (OH^?) ion dipole reorientations were observed. The one was very sharp, the other displayed a broad peak ranging from 350 to 550 K. While the broad peak can be attributed to the diffusive reorientation motions of OH^? ion dipoles, the sharp peak, related to the ferroelectric phase transition, implies the presence of ferroelectricity in HAp. The sharp peak was found near 380 K, the phase‐transition temperature from the monoclinic to hexagonal is ascribed to a critical phenomenon caused by the ferroelectric behavior of OH^? ion dipole reorientations.     

Design and Investigation of Heat Transfer in a New Adsorbent Bed With CPC for Solar Adsorption Refrigeration Systems

This article presents the design and the heat transfer study in a novel adsorbent bed with compound parabolic concentrator (CPC) for solar adsorption chillers. The objectives of the study were to investigate the heat transfer in the adsorbent bed experimentally, and to verify the fins layout through finite-element analysis (FEA) simulation. CPCs with different concentration ratios were experimentally tested and an appropriate design of CPC was selected for a prototype. The prototype was designed with the objective of improving the heat and mass transfer ability of the adsorbent bed. Fins were placed in the transverse direction under the receiver area of each CPC. Spaces were provided from three sides of the adsorbent for easy movement of the refrigerant. FEA software was used to study the effect of the fins layout and fins pitch. The experimental results showed that the heat was efficiently transferring up to the end and extended parts of the bed. Simulation results indicated that the present strategy of placing the fins in a transverse direction gives uniform heat distribution compared to a fins layout with fins placed in a longitudinal direction. The proposed design scheme will be helpful to improve the system performance by increasing the heat and mass transfer ability of an adsorbent bed.     

Mass imaging and identification of biomolecules with MALDI-QIT-TOF-based system

Imaging mass spectrometry is becoming a popular visualization technique in the medical and biological sciences. For its continued development, the ability to both visualize and identify molecules directly on the tissue surface using tandem mass spectrometry (MSn) is essential. We established an imaging system based on a matrix-assisted laser/desorption ionization quadrupole ion trap time-of-flight type instrument (AXIMA-QIT, Shimadzu, Kyoto, Japan), which was compatible with both imaging and highly sensitive MSn. In this paper, we present the operating conditions of the AXIMA-QIT as an imaging instrument and introduce the data converter we developed that is available free of charge. The converted data can be applied to Biomap, the commonly used visualization software. For the feasibility experiments, we demonstrated the visualization of phospholipids, glycolipid, and tryptic-digested proteins in the mouse cerebellum. The visualized lipids were successfully identified by MSn directly on the tissue surface, with a strong ability to isolate precursor ions. In the analysis of tryptic-digested proteins, we compared the product ion spectra between AXIMA-QIT and a tandem TOF-type instrument. The results confirmed that AXIMA-QIT can provide a high quality of product ion spectra even on the tissue surface.     

Emulsion grafting of vinyl acetate onto preirradiated poly(3‐hydroxybutyrate) film

Vinyl acetate (VAc) was grafted onto poly(3‐hydroxybutyrate) film by a preirradiation method. Grafting reactions were carried out in VAc/water/surfactant emulsion, VAc/water, and VAc/methanol systems. For emulsion grafting, Nonion L‐4 was ascertained to be the optimum surfactant with respect to the stability of a single emulsion layer. The emulsion with a 10 : 1 (w/w) ratio of VAc to surfactant yielded the highest degree of grafting: 23%. The grafting efficiency in the emulsion and the water and methanol solvents were evaluated. The results indicated that the grafting efficiency of the emulsion was 100 times that of VAc/methanol when the same 2 wt % VAc was used in the grafting reaction. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Parallel two-step phase-shifting digital holography

We propose a parallel two-step phase-shifting digital holography technique capable of instantaneous measurement of three-dimensional objects, with a view toward measurement of dynamically moving objects. The technique is based on phase-shifting interferometry. The proposed technique carries out the two-step phase-shifting method at one time and can be optically implemented by using a phase-shifting array device located in the reference beam. The array device has a periodic two-step phase distribution, and its configuration is simplified compared with that required for three-step and four-step parallel phase-shifting digital holographies. Therefore the optical system of the proposed technique is more suitable for the realization of a parallel phase-shifting digital holography system. We conduct both a numerical simulation and a preliminary experiment in the proposed technique. The results of the simulation and the experiment agree well with those of sequential phase-shifting digital holography, and results are superior to those obtained by conventional digital holography using the Fresnel transform alone. Thus the effectiveness of the proposed technique is verified.     

Increased horizontal viewing zone angle of a hologram by resolution redistribution of a spatial light modulator

The narrow viewing zone angle is one of the problems associated with electronic holography. We propose a technique that enables the ratio of horizontal and vertical resolutions of a spatial light modulator (SLM) to be altered. This technique increases the horizontal resolution of a SLM several times, so that the horizontal viewing zone angle is also increased several times. A SLM illuminated by a slanted point light source array is imaged by a 4f imaging system in which a horizontal slit is located on the Fourier plane. We show that the horizontal resolution was increased four times and that the horizontal viewing zone angle was increased approximately four times.     

Elimination of conjugate image for holograms using a resolution redistribution optical system

A technique to alter the ratio of the horizontal and vertical resolution of a spatial light modulator has been proposed. This technique increases the horizontal resolution by a factor of K and decreases the vertical resolution by a factor of 1/K. The proposed technique increases the horizontal viewing angle by a factor of approximately K, although a conjugate image appeared. In the present study, the resolution redistribution technique is modified to eliminate the conjugate image. The height of a horizontal slit placed on the Fourier plane of a 4 f imaging system used for the resolution redistribution system is reduced by half. The horizontal resolution becomes K times larger, and the vertical resolution becomes 1/2K times smaller. The improved technique generates only the object wave. We demonstrated fourfold enlargement of the horizontal resolution to increase the horizontal viewing angle by approximately four times without generating the conjugate image.     

Hole trapping in polydiacetylene field effect transistor studied by optical second harmonic generation

Hole trapping in polydiacetylene field effect transistor (PDA-FET) was studied by the electric field induced second harmonic generation (EFISHG). Response of SHG signal from PDA-FET with an application of external voltage was monitored. Applying positive voltage to source and drain electrodes with respect to gate electrode, SHG signal was not observed during bias application, whereas the signal was enhanced after turning off the bias. Since positive bias promotes hole injection from source and drain electrodes, electric field formed by trapped holes in PDA layer activated the SHG signal. Microscopic SHG measurement implies that the trapped holes are concentrated around source and drain electrodes.