Publications by authors named "K Hakamata"

We propose a novel scintillation detector design for positron emission tomography (PET), which has depth of interaction (DOI) capability and uses a single-ended readout scheme. The DOI detector contains a pair of crystal bars segmented using sub-surface laser engraving (SSLE). The two crystal bars are optically coupled to each other at their top segments and are coupled to two photo-sensors at their bottom segments.

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We demonstrated achromatic half- and quarter-wave plates for broadband terahertz pulses using phase retardation by internal total reflection. Prism-type wave plates realized ultra-broadband retardation stability up to 2.5 THz, which was the limitation of our experimental setup.

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Novel neutral glycosphingolipids (NGSLs) containing Gal-alpha1-->6Gal, previously found in the Zygomycetes species Mucor hiemalis, were synthesized. The structures of these compounds are different from those of other fungal GSLs, and they are expected to be involved in host-parasite interactions. A key step in their synthesis is direct 1,2-cis alpha-selective galactosylation of 4,6-diol tri- and tetrasaccharide acceptors with a galactosyl donor in the presence of N-iodosuccinimide (NIS)/trifluoromethanesulfonic acid (TfOH).

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Linoleic acid was encapsulated with a soluble soybean polysaccharide, gum arabic, or a mixture of both together with maltodextrin, and the oxidation process of the encapsulated acid was measured at 37 degrees C and at a relative humidity of 12%. The soybean polysaccharide was more effective for encapsulating the acid and suppressing the oxidation of the encapsulated acid than gum arabic. A mixture of the soybean polysaccharide and maltodextrin was also effective for this purpose when the weight fraction of the polysaccharide was equal to or greater than 0.

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Linoleic acid was emulsified with gum arabic or maltodextrin at various weight ratios of the acid to the polysaccharide in the presence or absence of a small-molecule emulsifier. The emulsions were spray-dried to produce microcapsules. Emulsions prepared with gum arabic were smaller in droplet size and more stable than those prepared with maltodextrin, and linoleic acid in a gum arabic-based microcapsule was also most resistant to oxidation than that in a maltodextrin-based microcapsule.

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