Using glycerinated spasmoneme of giant Zoothamnium sp., the physical properties of spasmoneme before and after Ca2+-induced contraction (pCa 4.5) were investigated. The volume change of spasmoneme contraction was measured under zero tension. The length and diameter decreased by about 50% of their initial value as a result of contraction, which means that contraction is nearly isotropic. Thus the volume of spasmoneme decreased drastically by 86% of its original value. The swollen ratio of extended and contracted spasmoneme were 0.07 and 0.37, respectively. Tension-extension relationships of extended and contracted spasmonemes were measured. By applying the theory of rubber elasticity, the number of segments of a chain in originally extended spasmoneme was only 3.3, i.e., the chain was almost a straight one. On the other hand, the number of segments of a chain in contracted spasmoneme was more than 100, i.e., the chain was essentially a random one. Furthermore, the total number of chains in single spasmoneme was the same in extended and contracted spasmoneme. This means that the interchain cross-links of chains were not influenced by addition or removal of Ca2+. Moreover, the molecular weight of a chain is estimated to be at most about 50 kd. By considering all these results, it is concluded that the contractile mechanism of spasmoneme originates in the intramolecular folding and unfolding induced by Ca2+ binding and detaching.

PurposeThe aim is to develop a force assistance system for standing‐up which prevents the decreasing of physical strength of the patient by using their remaining physical strength.Design/methodology/approachThe system realizes the standing up motion using the support bar with two degrees of freedom and the bed system which can move up and down. For using the remaining physical strength, our system uses the motion pattern which is based on the typical standing up motion by nursing specialist as control reference.FindingsThe assistance system realizes the natural standing up motion by nursing specialist and it is effective to assist the aged person to stand up without reducing their muscular strength.Originality/valueThe first idea is distributed system which controls the support bar and the bed system with coordination among them. The second idea is the combination of force and position control.

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Fluosol-DA 20%, a perfluorochemical emulsion consisting of 7 parts perfluorodecalin (FDC) and 3 parts perfluorotripropylamine (FTPA), has been used as an oxygen carrier in clinical studies. The emulsion, however, must be stored frozen because it is not stable for long in a liquid state. To increase the stability of perfluorochemical emulsions, a series of experiments on stability, elimination, and toxicity were conducted on different perfluorochemicals. F-4-Methyloctahydroquinolidizine (FMOQ) was selected as the best material. The tissue half-life of FMOQ in rats was estimated to be 7 days, which is the same as that of FDC, a perfluorochemical in Fluosol-DA 20%. FMOQ emulsified with a mixture of yolk phospholipid and Pluronic F-68 was stable at 4 degrees C for 6 months. Rats exchange-transfused to a hematocrit of 4% with this emulsion survived for 13 weeks.