␦-Catenin was first identified through its interaction withPresenilin-1 and has been implicated in the regulation of dendrogenesis and cognitive function. However, the molecular mechanisms by which ␦-catenin promotes dendritic morphogenesis were unclear. In this study, we demonstrated ␦-catenin interaction with p190RhoGEF, and the importance of Akt1-mediated phosphorylation at Thr-454 residue of ␦-catenin in this interaction. We have also found that ␦-catenin overexpression decreased the binding between p190RhoGEF and RhoA, and significantly lowered the levels of GTP-RhoA but not those of GTP-Rac1 and -Cdc42. ␦-Catenin T454A, a defective form in p190RhoGEF binding, did not decrease the binding between p190RhoGEF and RhoA. ␦-Catenin T454A also did not lower GTP-RhoA levels and failed to induce dendrite-like process formation in NIH 3T3 fibroblasts. Furthermore, ␦-catenin T454A significantly reduced the length and number of mature mushroom shaped spines in primary hippocampal neurons. These results highlight signaling events in the regulation of ␦-catenininduced dendrogenesis and spine morphogenesis.␦-Catenin was first identified by yeast two-hybrid screening as a molecule that interacts with Presenilin-1 (PS-1), 3 which is the most prominently mutated gene in familial Alzheimer disease (FAD) patients (1, 2). The interaction of ␦-catenin with PS-1, along with its abundant expression in neurons, suggests that ␦-catenin has specialized neuronal functions (3, 4). Indeed, ␦-catenin-deficient mice showed severe learning deficits and abnormal synaptic plasticity, suggesting a special role of ␦-catenin at the synapse (5). Furthermore, the hemizygous loss of the chromosomal 5p15.2 region, which contains the human ␦-catenin gene, results in the severe mental retardation associated with Cri du Chat syndrome. This chromosomal abnormality may account for 1% of all mentally retarded individuals (6).Structural analysis indicated that ␦-catenin is a member of the p120-Catenin (hereafter, p120 ctn ) subfamily of armadillo proteins and has a DSWV sequence at the C terminus that binds to the PDZ (PSD-95/Disc-larg/ZO-1) domain-containing proteins (7). ␦-Catenin also contains SH3 binding domains at the N terminus (4, 8), a GKKKKKKK sequence (putative NLS) that can potentially promote lipid intermixing (9), and a proline-rich domain that is likely to be involved in the interaction with the actin-binding protein, Profilin (4). The presence of 10 Arm repeats in ␦-catenin suggests its potential participation in various protein-protein interactions. In addition to PS-1, the ␦-catenin-associated proteins identified thus far include E-cadherin (4), S-SCAM (7), p0071 (10), Densin-180 (11), PSD-95, Abl (8), Cortactin (12), sphingosine kinase (13), and Kaiso (14), suggesting its many possible roles in cells. Our previous reports demonstrated that the overexpression of ␦-catenin induces the branching of dendrite-like processes in both NIH 3T3 fibroblasts and primary hippocampal neurons (15). We have also reported that an E18 hippocampal neuron ...

A wheel drive mechanism is simple, stable, and efficient, but its mobility in unstructured terrain is seriously limited. Using a deformable wheel is one of the ways to increase the mobility of a wheel drive robot. By changing the radius of its wheels, the robot becomes able to pass over not only high steps but also narrow gaps. In this article, we propose a novel design for a variable-diameter wheel using an origami-based soft robotics design approach. By simply folding a patterned sheet into a wheel shape, a variable-diameter wheel was built without requiring lots of mechanical parts and a complex assembly process. The wheel's diameter can change from 30 to 68 mm, and it is light in weight at about 9.7 g. Although composed of soft materials (fabrics and films), the wheel can bear more than 400 times its weight. The robot was able to change the wheel's radius in response to terrain conditions, allowing it to pass over a 50-mm gap when the wheel is shrunk and a 50-mm step when the wheel is enlarged.

DNA-based data storage has emerged as a promising method to satisfy the exponentially increasing demand for information storage. However, practical implementation of DNA-based data storage remains a challenge because of the high cost of data writing through DNA synthesis. Here, we propose the use of degenerate bases as encoding characters in addition to A, C, G, and T, which augments the amount of data that can be stored per length of DNA sequence designed (information capacity) and lowering the amount of DNA synthesis per storing unit data. Using the proposed method, we experimentally achieved an information capacity of 3.37 bits/character. The demonstrated information capacity is more than twice when compared to the highest information capacity previously achieved. The proposed method can be integrated with synthetic technologies in the future to reduce the cost of DNA-based data storage by 50%.

A 10 nm nano-silica was introduced to a conventional 3 μm micro-silica composite to develop an eco-friendly new electric insulation material for heavy electric equipment. Thermal and mechanical properties, such as glass transition temperature (Tg), dynamic mechanical analysis, tensile and flexural strength, were studied. The mechanical results were estimated by comparing scale and shape parameters in Weibull statistical analysis. The thermal and mechanical properties of conventional epoxy/micro-silica composite were improved by the addition of nano-silica. This was due to the increment of the compaction via the even dispersion of the nano-silica among the micro-silica particles.

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Cell-tracking methods with molecular-imaging modality can monitor the biodistribution of cells. In this study, the direct-labeling method with 64 Cu-pyruvaldehyde-bis(N4-methylthiosemicarbazone) ( 64 Cu-PTSM), indirect cell-labeling methods with herpes simplex virus type 1-thymidine kinase (HSV1-tk)-mediated 124 I-2¢-fluoro-2¢-deoxy-1-b-d-arabinofuranosyl-5-iodouracil ( 124 I-FIAU) were comparatively investigated in vitro and in vivo for tracking of human chronic myelogenous leukemia cells. K562-TL was established by retroviral transduction of the HSV1-tk and firefly luciferase gene in the K562 cell. K562-TL cells were labeled with 64 Cu-PTSM or 124 I-FIAU. Cell labeling efficiency, viability, and radiolabels retention were compared in vitro. The biodistribution of radiolabeled K562-TL cells with each radiolabel and small-animal positron emission tomography imaging were performed. Additionally, in vivo and ex vivo bioluminescence imaging (BLI) and tissue reverse transcriptasepolymerase chain reaction (RT-PCR) analysis were used for confirming those results. K562-TL cells were efficiently labeled with both radiolabels. The radiolabel retention (%) of 124 I-FIAU (95.2% -1.1%) was fourfold higher than 64 Cu-PTSM (23.6% -0.7%) at 24 hours postlabeling. Viability of radiolabeled cells was statistically nonsignificant between 124 I-FIAU and 64 Cu-PTSM. The radioactivity of each radiolabeled cells was predominantly accumulated in the lungs and liver at 2 hours. Both the radioactivity of 64 Cu-PTSM-and 124 I-FIAU-labeled cells was highly accumulated in the liver at 24 hours. However, the radioactivity of 124 I-FIAU-labeled cells was markedly decreased from the body at 24 hours. The K562-TL cells were dominantly localized in the lungs and liver, which also verified by BLI and RT-PCR analysis at 2 and 24 hours postinjection. The 64 Cu-PTSM-labeled cell-tracking method is more efficient than 124 I-FIAU-labeled cell tracking, because of markedly decrease of radioactivity and fast efflux of 124 I-FIAU in vivo. In spite of a high labeling yield and radiolabel retention of 124 I-FIAU in vitro, the in vivo cell-tracking method using 64 Cu-PTSM could be a useful method to evaluate the distribution and targeting of various cell types, especially, stem cells and immune cells.

As noted in Table 1, the epoxy resins that are not made with nano-fillers are referred to as conventional epoxy resins and the composites in which the conventional micro scaled epoxies are made with nano-fillers are referred to as epoxy nano-and-micro mixture composites (ENMCs). Three different ENMCs were fabricated with the composition ratios shown in Table 1.As this table shows, all of the epoxies were made with the same basic ratios of resin, hardener, and microparticles. The three different ENMCs are differentiated by nano SiO 2 concentrations of 0.5, 1, and 5 phr. In addition, this study looked at the effects of the silane processing (silane coupling agent: KBE_903_2.5 phr) for the micro composites. Keywords:Epoxy nano-and-micro mixture composites, Microcomposites, Cross-linking density, Differential scanning calorimeter, Dynamic mechanical analyser This study investigates the thermal and mechanical properties of insulation elements through the mixing of epoxy based micro and nano particles. Regarding their thermal properties, differential scanning calorimeter and dynamic mechanical analyser were used to calculate the cross-linking densities for various types of insulation elements. The mechanical properties of the bending strength, the shape and scale parameters, were obtained using the Weibull plot. This study obtained the best results in the scale parameters, at 0.5 phr, for the bending strength of the epoxy nanoand-micro mixture composites.