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Histone demethylase UTX mediates removal of repressive trimethylation of histone H3 lysine 27 (H3K27me3) to establish a mechanistic switch to activate large sets of genes. Mutation of Utx has recently been shown to be associated with Kabuki syndrome, a rare congenital anomaly syndrome with dementia. However, its biological function in the brain is largely unknown. Here, we observe that deletion of Utx results in increased anxiety-like behaviors and impaired spatial learning and memory in mice. Loss of Utx in the hippocampus leads to reduced long-term potentiation and amplitude of miniature excitatory postsynaptic current, aberrant dendrite development and defective synapse formation. Transcriptional profiling reveals that Utx regulates a subset of genes that are involved in the regulation of dendritic morphology, synaptic transmission, and cognition. Specifically, Utx deletion disrupts expression of neurotransmitter 5-hydroxytryptamine receptor 5B (Htr5b). Restoration of Htr5b expression in newborn hippocampal neurons rescues the defects of neuronal morphology by Utx ablation. Therefore, we provide evidence that Utx plays a critical role in modulating synaptic transmission and cognitive behaviors. Utx cKO mouse models like ours provide a valuable means to study the underlying mechanisms of the etiology of Kabuki syndrome.

In this study, flexible and uniform multiwall carbon nanotube embedded polydimethylsiloxane (PDMS) sheets were prepared using a vacuum filtration and transfer process. The resistance of the sheets and microstructures were investigated for the fabrication of ideal probe-fed and microstrip-fed patch antennas. Simulation results showed that the resonance and gain of an antenna were affected by the conductivity of the patch significantly. The return loss and gain are acceptable when a conductivity of 10 5 S/m is used. The stretchability test indicated that a gold-coated sheet was more stable than a pristine sheet. Its resistance has a change of 0.5% only, with a displacement of 2500 μm. The frequency-tuning capability was demonstrated using an air inflatable microstrip-fed patch antenna. The working frequency can be tuned by 6.5% with a displacement of 1500 μm, which was higher than that of previously reported MEMS bridge and electrostatic force tunable antennas. This is the first time that a frequency tunable antenna fabricated by PDMS/carbon nanotube is reported. The optimization methods for this type of antenna are discussed and some potential applications such as remote wireless pressure sensors are proposed.

In this study, the effects of sodium dodecyl benzene sulfonate, polyvinylpyrrolidone, sodium dodecyl benzene sulfonate/polyvinylpyrrolidone, and Triton X-100 on the dispersion of 0.1 wt% carbon nanotubes in dimethylacetamide are reported. Sedimentation results show that except for sodium dodecyl benzene sulfonate, all the surfactant-assisted carbon nanotube solutions have visually-stable dispersions for at least two months, and even the samples without a surfactant gave no obvious deposition. UV-Vis spectra of the dispersions with and without acid-treatment proved that the carboxyl group attached to the carbon nanotubes positively improves the dispersion effect. The states of aggregation of carbon nanotubes treated by different surfactants are distinctive, and the electrical properties of carbon nanotubes are strongly related to these states of aggregation. The best dispersing and stabilizing effect was found in the sodium dodecyl benzene sulfonate/polyvinylpyrrolidone sample, which also gave the lowest resistance (2.15 x 10(4) omega at 20 V) among all the surfactant-treated stable suspensions.

The dispersion and stability of carbon nanotubes (CNTs) inside a polymer matrix, especially with a high CNT content, are still big challenges. Moreover, the interaction between CNTs and the polymer matrix should be strong enough to improve the mechanical properties. The efficient dispersion of CNTs is essential for the formation of a uniform distribution of a CNT network in a polymer composite. Polyimide/multiwall CNT nanocomposites were synthesized by in situ polymerization with the aid of a surfactant. A Fourier transform infrared spectroscopy study proved that the surfactant did not hamper the polymerization of the polyimide. The microstructure, storage modulus and electrical conductivity of the nanocomposites were improved using a particular amount of the surfactant. Environmental stability test results showed that the polyimide with 1 wt% of CNTs produced with the aid of the surfactant possessed excellent reliability in high-temperature and high-humidity environments. Surfactants were successfully used to obtain fine-structure polyimide/CNT nanocomposites by in situ polymerization. The enhancement of the mechanical properties was attributed to the incorporation of the surfactant. A percolation of electrical conductivity could be achieved with 1 wt% of CNTs. Copyright © 2010 Society of Chemical Industry

Powders of Nd/V-doped Bi4Ti3O12 with a composition Bi3.74Nd0.26Ti2.98V0.02O12.01 (BNTV), prepared by the molten salt synthesis, using chlorides as the fluxes, were successfully obtained. The influences of the molar ratio of KCl to NaCl, temperature, and soak time on the formation and morphology of BNTV were investigated. The results indicated that Na+ can enter the lattice of Bi4Ti3O12 (BIT), leading to a decrease in the cell dimensions of BIT phase. The grain size and morphology of BNTV powders were considerably affected by the molar ratio of KCl to NaCl in the fluxes, in which the platelets showed the morphology of a rectangle and no regular shape in KCl and NaCl fluxes, respectively. The grain size of BNTV increased with increasing amount of NaCl in the fluxes, but the thickness decreased. The platelets prepared in the NaCl flux were faceted along (0 0 1) plane.

Antennas that are fabricated by traditional processes are hard to be reconfigured to a curved shape after fabrication. While, foldable and stretchable antennas are attractive for applications now, such as sensors and can be integrated into textiles and clothes for wearable electronics and out-of-plane designs. In this research, we used polydimethylsiloxane, carbon nanotubes, gold and some secondary raw materials to design and fabricate two types of frequency-tunable soft composite antennas for wireless sensing, utilizing vacuum filtration and transfer process. And after fabrication, we characterized the frequency properties for both of them.

A versatile capacitive tactile sensor based on transparent flexible materials is developed in a simple and low-cost fabrication process. The sensor shows an excellent sensitivity (S=2.05 N-1), and is highly sensitive to the load as low as about 3 mN. Moreover, it exhibits a prominent resolution. The excellent device performance is attributed to the creative design of polydimethylsiloxane (PDMS) polymer layer, used as the structural material of the sensor, in which each sensing section acting as a sensor unit is a concave square with hemispheric micro-structured PDMS arrays. Meanwhile, other sections without any PDMS arrays serving as perfect natural wall-barriers can make each sensor unit separated effectively.