Mitogen-activated protein kinases (MAPKs) are integral to the mechanisms by which cells respond to physiological stimuli and to a wide variety of environmental stresses. MAPK cascades can be inactivated at the MAPK activation step by members of the MAPK phosphatase (MKP) family. However, the components that act in MKP-regulated pathways have not been well characterized in the context of whole organisms. Here we characterize the Caenorhabditis elegans vhp-1 gene, encoding an MKP that acts preferentially on the c-Jun N-terminal kinase (JNK) and p38 MAPKs. We found that animals defective in vhp-1 are arrested during larval development. This vhp-1 defect is suppressed by loss-of-function mutations in the kgb-1, mek-1, and mlk-1 genes encoding a JNK-like MAPK, an MKK7-type MAPKK, and an MLK-type MAPKKK, respectively. The genetic and biochemical data presented here demonstrate a critical role for VHP-1 in the KGB-1 pathway. Loss-of-function mutations in each component in the KGB-1 pathway result in hypersensitivity to heavy metals. These results suggest that VHP-1 plays a pivotal role in the integration and fine-tuning of the stress response regulated by the KGB-1 MAPK pathway.

6‐Aminohexanoic‐acid‐oligomer hydrolase of Flavobacterium sp. KI72 was purified to homogeneity by column chromatography three times, and by preparative polyacrylamide gel electrophoresis twice. The purified enzyme had the following characteristics. The molecular weight was estimated to be 84000 by Sephadex G‐200 molecular‐sieve chromatography. The enzyme consisted of two homologous subunits of 42000, judged from sodium dodecylsulfate/polyacrylamide gel electrophoresis. The optimum pH for activity was between 8 and 9, the optimum temperature was 40° C for a 1‐h reaction. The Michaelis‐Menten constants and turnover numbers for the 6‐aminohexanoic acid dimer and trimer were 5.9 mM and 2.4 s−1, and 6.2 mM and 2.0 s−1 respectively. The enzyme was inhibited by 0.37 mM diisopropylfluorophosphate and by 0.013 mM p‐chloromercuribenzoate. The enzyme was active on 6‐aminohexanoic acid oligomers from dimer to hexamer and icosamer but not on hectamer, and the activity decreased with the increase of the polymerization number of the ougomer. The oligomers were hydrolyzed so as to remove the 6‐aminohexanoic acid residue successively from the amino terminus. The enzyme could not hydrolyze other linear amides, cyclic amides, dipeptides, tripeptides or casein. 6‐Aminohexanoic‐acid‐oligomer hydrolase was classified as a new member of the linear amidases (EC 3.5.1.‐).

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Layered silicene with deformed buckled structure attracts great interest as a next generation 2D Dirac thermoelectric material beyond conventional layered materials. However, the difficulty of modulating atomic positions in silicene prevents its realization. This study proposes a method to deform buckled structure in layered silicene by controlling the intercalated atoms, which can dramatically enhance its thermoelectric properties. Silicene buckled structure is deformed in epitaxial CaSi2 thin films, Ca‐intercalated layered silicenes, on Si(111) substrates, which is related to the composition of intercalated Ca. Therein, buckling height of silicene is changed. This CaSi2 film with deformed silicene exhibits not only metal‐like electrical conductivity but also three times larger Seebeck coefficient than the theoretically predicted value, resulting in ≈3000 times larger power factor (≈40 μW cm−1 K−2) than that of the reported CaSi2 film at room temperature. This result experimentally demonstrates that power factor can be greatly enhanced by deforming the silicene buckled structure.

For realization of new informative systems, the memristor working like synapse has drawn much attention. We developed isolated high-density Fe 3 O 4 nanocrystals on Ge nuclei/Si with uniform and high resistive switching performance using low-temperature growth. The Fe 3 O 4 nanocrystals on Ge nuclei had a well-controlled interface (Fe 3 O 4 /GeO x /Ge) composed of highcrystallinity Fe 3 O 4 and high-quality GeO x layers. The nanocrystals showed uniform resistive switching characteristics (high switching probability of~90%) and relatively high Off/On resistance ratio (~58). The high-quality interface enables electric field application to Fe 3 O 4 and GeO x near the interface, which leads to effective positively charged oxygen vacancy movement, resulting in high-performance resistive switching. Furthermore, we successfully observed memory effect in nanocrystals with well-controlled interface. The experimental confirmation of the memory effect existence even in ultrasmall nanocrystals is significant for realizing non-volatile nanocrystal memory leading to neuromorphic devices.

We investigated thermal conductivity of epitaxial germanane films: stacked structure of hydrogenated germanenes. It was confirmed that single crystalline germanane films were epitaxially grown on Ge(111). The films exhibited low out-of-plane thermal conductivity of 1.1 ± 0.3 W m−1 K−1 which is lower than other layered materials composed of heavy atoms. This came from weak van der Waals interlayer interaction related to weak polarization in germanane composed of smaller atoms. This demonstrates that choice of small constituent atoms for weakening van der Waals interlayer interaction is a promising thermal conductivity reduction outline for developing ecofriendly high performance thermoelectric layered materials.

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