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Electroactive polymer transducers have many features that are desirable for various devices. An especially attractive type of electroactive polymer is dielectric elastomer (DE). Our recent progress is a DE actuator having only 0.1 g of DE that lifted a weight of 2 kg using carbon system electrodes. We also developed a ribbon form DE actuator having a sensor function that can be used to measure force, or pressure, as well as motion at the same time. This actuator can assist human and robot motions. At the same time, it can work as a motion feedback sensor. We hope that it may be useful for smart rehabilitation equipment for hands, legs, and fingers. DE has also been shown to operate in reverse as a generator. Experiments have been performed on portable DE generators/wearable generators powered by human motion, ocean wave power harvesters mounted on buoys, solar heat generators, and water turbines. While the power output levels of such demonstration devices is small, the performance of these devices has supported the potential benefits of DE. We are developing elastomers having larger dielectric constant using barium titanium oxide to produce a “super artificial muscle for energy harvesting devices, actuators & sensors” in the near future.

Background & Aims:: Tissue recruitment of dendritic cells (DCs) is essential for antigen presentation. This study aimed to examine cellular and molecular mechanisms for DC recruitment to the liver. Methods:: Purified rat DCs were injected into circulation and their traffics were analyzed in normal and Kupffer cell-depleted rats by intravital confocal microscopy and immunohistology. Affinities of DCs to sinusoidal cells were examined by a cell-binding assay. DC precursor recruitment was induced by particulate injection. Results:: Both DC precursors and DCs at the antigen-transporting stage could be recruited to the liver, and their majority initially showed a selective binding to Kupffer cells. In the Kupffer cell-depleted rats, DCs could neither be recruited to the liver nor adhere to sinusoidal walls. Pretreatment with varied monosaccharides showed that sugar residues consisting of N-acetylgalactosamine were necessary for this binding. The binding was calcium-dependent, implying the C-type lectin involvement. Furthermore, DCs could endocytose N-acetylgalactosamine polymers in a receptor-specific manner. Conclusions:: The DC-Kupffer cell binding through N-acetylgalactosamine-specific C-type lectin-like receptors is crucial for DC recruitment to the liver. Rat DCs at least partly possess receptors for endocytosis of galactosylated antigens. These DC receptors as well as Kupffer cell lectins are presumably responsible for this binding.

NADP-dependent formate dehydrogenase (NADP+) (EC 1.2.1.43) from Clostridium thermoaceticum has been purified to a specific activity of about 1100 mumol min-1 mg-1 when assayed at 55 degrees C and pH 7.5. The enzyme is extremely oxygen-sensitive and 7.6 microM of O2 causes 50% inhibition of initial velocity under assay conditions. Purification was done in an atmosphere at 95% N2 and 5% H2 and by including azide, dithionite, and glycerol as stabilizing agents in all buffer solutions. The enzyme contains, in molar ratios, 2 tungsten, 2 selenium, 36 iron, and about 50 inorganic sulfur. It has a molecular weight of about 340,000 and consist of two each of two different subunits giving the composition alpha 2 beta 2. The molecular weight of the alpha-subunit is 96,000 and that of the beta-subunit is 76,000. The selenium resides in the two alpha-subunits. Tungsten is released from the protein on denaturation and may exist as a tungsten cofactor. The enzyme catalyzes a reduction of CO2 with NADPH at pH 7.5 and 55 degrees C and Keq at these conditions is (2.35 +/- 0.49) x 10(-2) if CO2 is considered the active species and (1.48 +/- 0.31) x 10(-3) if HCO3- is the active species.

Seismic shaking has been regarded as an essential source of resurfacing on asteroids. The Small Carry‐on Impactor (SCI) operation on Hayabusa2 has been expected to be a unique opportunity for testing in situ seismic shaking whose energy is sufficiently large to excite observable surface modification. However, no obvious regolith hopping was identified even immediately outside of the crater formed by the SCI impact. To understand this discrepancy from the expectation, we simulate seismic wave propagation on Ryugu with a wide range of surface material properties and evaluate maximum acceleration on the surface. Numerical results reveal that low‐quality factor or low seismic efficiency is required to explain the lack of geomorphological change after the SCI experiment. Considering that scattering under anhydrous conditions cannot efficiently dissipate energy, such a low‐quality factor is not plausible. The weak yield strength in porous materials can efficiently decrease seismic wave energies, making the apparent seismic efficiency extremely low. Based on this hypothesis, we propose a formulation of surface mobility on asteroids that considers the physical properties of regolith. We consistently estimate the occurrence of seismic shaking with the existence of unstable boulders on Ryugu. The Japanese asteroid exploration mission, Hayabusa2, successfully performed an artificial impact cratering operation on April 5, 2019. Extensive surface modification was expected to be excited by the impact‐induced seismic waves; however, boulders stayed at almost the same location. We conduct seismic wave propagation simulations to resolve this apparent discrepancy and to understand the physical properties of Ryugu. We show that surface changes are strongly dependent on a shallow subsurface. Our results suggest that the conversion of impact energy to seismic waves is less efficient than previously thought. The weakness of powdery regolith may limit asteroid‐quakes at the surface. Based on this hypothesis, we propose a formulation how the surface moves on asteroids that considers the unclear properties of regolith. The lack of seismic shaking agrees with the mysterious discovery that boulders stay unstably on other boulders. Unexpectedly little movement of boulders due to the Small Carry‐on Impactor impact experiment on Ryugu is investigated by seismic wave propagation simulationLow‐yield strength of asteroid regolith is likely to limit seismic wave amplitudeMeteoroid impacts on small asteroids possibly cause seismic shaking, but its contribution to resurfacing is localized Unexpectedly little movement of boulders due to the Small Carry‐on Impactor impact experiment on Ryugu is investigated by seismic wave propagation simulation Low‐yield strength of asteroid regolith is likely to limit seismic wave amplitude Meteoroid impacts on small asteroids possibly cause seismic shaking, but its contribution to resurfacing is localized

A novel multiregulation system of ion recognition was constructed by utilizing a molecular gate. Interaction between the host and an Ag⁺ is controlled with an Na⁺ ion.