セルラーゼ処理による部分カルボキシメチル化綿のモルホロジー観察 (original) (raw)
FIBER, 2005
Cotton fabrics modified by carboxymethylation to the degree of substitution (DS) of 0.02~0.16 were separated into the salt-type CM-Cotton-Na with more water swelling and the acid-type CM-Cotton-H with less water swelling. The two types of cotton fabrics were treated with a commercially available cellulase product. For CM-Cotton-Na and CM-Cotton-H, the weight loss and the saccharification activities of the cellulase decreased with DS of 0.10 or less. The modification by carboxymethylation for cotton fabrics inhibited apparently the catalytic reaction of the cellulase. For CM-Cotton-Na and CM-Cotton-H, the cellulase showed the minimum value of the weight loss activity at DS of 0.10 and that of the saccharification activity at DS of 0.14. For CM-Cotton-Na, the cellulase exhibited larger value of the weight loss activity and smaller value of the saccharification activity at DS of 0.16 compared to the unmodified cotton fabric. We discussed that the endo-type cellulase attacked positively to CM-Cotton-Na with DS of 0.10 or more because of its more water swelling, but attacked negatively to CM-Cotton-H because of its less water swelling. On the other hand, the exo-type cellulase was inhibited to attack the modified cotton fabrics with DS of 0.10 or more.
JOURNAL OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, 2003
Forebody and aftbody radiative heating rates of the MUSES-C asteroid sample return capsule have been assessed along the reentry trajectory from an engineering standpoint. Nonequilibrium hypersonic flows around the capsule with ablation of the thermal protection system involved were determined by CFD calculations, while the radiative heat transfer was computed by the radiation code SPRADIAN in a non-coupled manner with the flow analysis. In order to take into account much uncertainty in the thermal relaxation, chemical reaction, and ablation models used in the flow analysis, parametric studies were performed by changing these models to obtain the conservative estimation of the radiative environments. The radiative heat flux was found to be considerably affected by the ablation model, especially in the aftbody region of the capsule.
Effect of adhesion minimization on pluripotency of mESCs cultured on microstructured mesh sheets
The Proceedings of Mechanical Engineering Congress, Japan, 2017
Pluripotent stem cells have the ability to generate multicellular tissues with cooperative cell differentiation and movement. During such self-organizing process, cells adjust their fates and behaviors depending on mechanical and geometric environment through 2 types of cell adhesion; cell-substrate and cell-cell adhesion. Here we investigated changes in pluripotency of mouse embryonic stem cells cultured on microstructured mesh sheets in LIF-supplemented pluripotency maintenance medium. The mesh sheets, microfabricated using photolithography, have large mesh openings and narrow mesh strands, hence cell-substrate adhesion area is minimized. Upon seeding, cells attached to the strands were able to proliferate, fill the mesh openings and form sheet-like tissues. Immunofluorescence microscopy revealed that the cells expressed pluripotency markers at 3rd day after seeding. Interestingly, the sheet-like tissues spontaneously became thicker and finally generated spherical cyst-like tissues attributable to cell differentiation. Thus, our results suggest that modulating the cell-substrate adhesion induces these self-organizing morphological changes in 2 steps; sheet-like tissues relying on cell-cell adhesion to overcome substrate restriction and spherical cyst-like tissues accompanied by loss of pluripotency. This research may help to build up a new platform for studying pluripotent stem cell self-organization leading to the generation of functional organoids.