No abstract

The fabrication of deformable devices has been explored by interconnecting nonstretchable unit devices with stretchable conductors or by developing stretchable unit devices consisting of all stretchable device components such as electrodes, active channels, and dielectric layers. Most researches have followed the first approach so far, and the researches based on the second approach are at the very beginning stage. This paper discusses the perspectives of the second approach, specifically focusing on the polymer semiconductor channel layers, that is expected to facilitate high density device integration in addition to large area devices including polymer solar cells and light-emitting diodes. Three different routes are suggested as separate sections according to the principles imparting stretchability to polymer semiconductor layers: structural configurations of rigid semiconductors, two-dimensional network structure of semiconductors on elastomer substrates, and ductility enhancement of semiconductor films. Each section includes two subsections divided by the methodological difference. This Perspective ends with discussion on the future works for the routes and the challenges related to other device components.

DNA catalysts (deoxyribozymes) for a variety of reactions have been identified by in vitro selection. However, for certain reactions this identification has not been achieved. One important example is DNA-catalyzed amide hydrolysis, for which a previous selection experiment instead led to DNA-catalyzed DNA phosphodiester hydrolysis. Subsequent efforts in which the selection strategy deliberately avoided phosphodiester hydrolysis led to DNA-catalyzed ester and aromatic amide hydrolysis, but aliphatic amide hydrolysis has been elusive. In the present study, we show that including modified nucleotides that bear protein-like functional groups (any one of primary amino, carboxyl, or primary hydroxyl) enables identification of amide-hydrolyzing deoxyribozymes. In one case, the same deoxyribozyme sequence without the modifications still retains substantial catalytic activity. Overall, these findings establish the utility of introducing protein-like functional groups into deoxyribozymes for identifying new catalytic function. The results also suggest the longer-term feasibility of deoxyribozymes as artificial proteases.

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In Parkinson's disease (PD), neuroinflammation plays a critical role in the neurodegenerative process. Furthermore, activated microglia and astrocytes, responsible for activated immune response in the central nervous system, are found in regions associated with dopaminergic neuronal death. The flavonoid baicalein is known to have antibacterial, antiviral, and antiinflammatory activities. In the present study, the neuroprotective effects of baicalein were examined in a murine 1-methyl-4-phenyl-1,2,3,4-tetrahydropyridine (MPTP) model of PD. Low doses of baicalein improved motor ability and prevented dopaminergic neuron loss caused by MPTP. In addition, microglial and astrocyte activations were reduced in PD mice pretreated with baicalein. Further study of primary astrocytes revealed that baicalein suppressed the 1-methyl-4-phenylpyridine-induced nuclear translocation of nuclear factor-κB and reduced the activations of JNK and ERK, suggesting that the neuroprotective effects of baicalein in our PD model were due to attenuated astrocyte activation. The findings of this study indicate that baicalein could be useful for the treatment of PD and other neuroinflammation-related neurodegenerative diseases.