Stretchable and Conductive Polymer Films Prepared by Solution Blending

Stretchable and conductive materials can have important application in many areas, such as wearable electronics and healthcare devices. Conducting polymers have very limited elasticity because of their rigid conjugated backbone. In this work, highly stretchable and conductive polymer films are prepared by coating or casting aqueous solution of poly­(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) and a soft polymer, including poly­(ethylene glycol), poly­(ethylene oxide), or poly­(vinyl alcohol). The soft polymers can greatly improve the stretchability and the conductivity of PEDOT:PSS. The elongation at break can be increased from 2% up to 55%. The soft polymers can also enhance the conductivity of PEDOT:PSS from 0.2 up to 75 S cm^–1. The conductivity is further enhanced by adding dimethyl sulfoxide (DMSO) or ethylene glycol (EG) into the aqueous solutions of the polymer blends. Polymer blends with an elongation at break of close to 50% and a conductivity of 172 S cm^–1 are attained

Nitrogen-Doped Reduced Graphene Oxide Prepared by Simultaneous Thermal Reduction and Nitrogen Doping of Graphene Oxide in Air and Its Application as an Electrocatalyst

Graphene is considered to be one of the most interesting materials because of its unique two-dimensional structure and properties. However, commercialization and large-scale production of graphene still face great challenges at the moment. Thermal reduction of graphene oxide (GO) can be an effective method to fabricate graphene in large scale, but the need for inert gas protection and high reaction temperature leads to high cost of production, thus limiting the production capacity of graphene. In this paper, for the first time we report a facile, safe, and scalable method to achieve simultaneous thermal reduction and nitrogen doping of GO in air at much lower reaction temperature while upholding a high-quality end product. The reduction and nitrogen doping of GO are evidenced by ultraviolet–visible absorption spectroscopy, X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The nitrogen-doped reduced GO (NrGO) fabricated via this method has a high carbon/oxygen ratio of 15 and a nitrogen content of 11.87 atom %. The NrGO is also investigated by applying it as an electrocatalyst for the oxygen reduction reaction. As a result, the catalytic activity has presented itself as much higher than that of the undoped rGO

Study on Silicon-Containing Main Chain Type Polybenzoxazines with Both High Heat Resistance and Low Dielectric Constant

Polymeric materials with high heat resistance and low dielectric constants are desired for fast communication. To realize this purpose, two kinds of silicon-containing main chain type benzoxazines with and without an acetylene group, (ABA-Si-ala)main and (ABA-Si-a)main, were designed and synthesized from polyphenol oligomers, primary amines, and paraformaldehyde. Their chemical structures were characterized and verified by Fourier transform infrared (FTIR) spectra and nuclear magnetic resonance (NMR) spectra. Moreover, their curing behaviors and polymerization reactions were studied by differential scanning calorimetry (DSC) and FTIR spectra, and cross-linking structures were proposed. Furthermore, thermal properties of the two polybenzoxazines were analyzed by dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA). The results showed that poly(ABA-Si-ala)main exhibited excellent heat resistance and thermal stability, and its Tg and char yield at 800 °C under N2 reached as high as 308 °C and 48.5%, respectively, which were higher than those of poly(ABA-Si-a)main. In particular, the existence of the siloxane structure endowed the two polybenzoxazines with good dielectric properties, and the dielectric constants of poly(ABA-Si-ala)main and poly(ABA-Si-a)main were as low as 2.78 and 2.67 at 1 GHz, respectively. Such low dielectric constants will be necessary and vital for signal transmission. Therefore, this work provides a new and effective strategy for designing new polymers with both excellent heat resistance and low dielectric constants

Effect arylamine N-acetyltransferase 1 on morphology, adhesion, migration, and invasion of MDA-MB-231 cells: role of matrix metalloproteinases and integrin αV

Reducted arylamine N-acetyltransferase (NAT1) in breast cancers is associated with poor patient survival. NAT1 has also been associated with changes in cancer cell survival and invasion both in vitro and in vivo. Here, we report the effects of NAT1 in cancer cell invasion by addressing its role in adherence, migration, and invasion in vitro. The NAT1 gene was deleted in MDA-MB-231, HT-29 and HeLa cells using CRISPR/Cas9 gene editing. Loss of NAT1 increased adherence to collagen in all three cell-lines but migration was unaffected. NAT1 deletion decreased invasion and induced changes to cell morphology. These effects were independent of matrix metalloproteinases but were related to integrin ITGαV expression. The data suggest NAT1 is important in adhesion and invasion through integrin expression.</p

Additional file 1 of Cortical spreading depression induces propagating activation of the thalamus ventral posteromedial nucleus in awake mice

Additional file 1. The dynamic fluorescence changes of ipsilateral VPM neuronal activity during CSD in awake mice. The increase in neural activity in the VPM induced by CSD showed a “propagating-like” spatial pattern that spread from the posterior-lateral to the anterior-medial side of the VPM. The left side showed the original fluorescence signal, the right side showed the relative fluorescence change

Modeling the Contributions of Ca²⁺ Flows to Spontaneous Ca²⁺ Oscillations and Cortical Spreading Depression-Triggered Ca²⁺ Waves in Astrocyte Networks

<div><p>Astrocytes participate in brain functions through Ca²⁺ signals, including Ca²⁺ waves and Ca²⁺ oscillations. Currently the mechanisms of Ca²⁺ signals in astrocytes are not fully clear. Here, we present a computational model to specify the relative contributions of different Ca²⁺ flows between the extracellular space, the cytoplasm and the endoplasmic reticulum of astrocytes to the generation of spontaneous Ca²⁺ oscillations (CASs) and cortical spreading depression (CSD)-triggered Ca²⁺ waves (CSDCWs) in a one-dimensional astrocyte network. This model shows that CASs depend primarily on Ca²⁺ released from internal stores of astrocytes, and CSDCWs depend mainly on voltage-gated Ca²⁺ influx. It predicts that voltage-gated Ca²⁺ influx is able to generate Ca²⁺ waves during the process of CSD even after depleting internal Ca²⁺ stores. Furthermore, the model investigates the interactions between CASs and CSDCWs and shows that the pass of CSDCWs suppresses CASs, whereas CASs do not prevent the generation of CSDCWs. This work quantitatively analyzes the generation of astrocytic Ca²⁺ signals and indicates different mechanisms underlying CSDCWs and non-CSDCWs. Research on the different types of Ca²⁺ signals might help to understand the ways by which astrocytes participate in information processing in brain functions.</p> </div

Schematic diagram of the model.

<p>The stimulated cortex was divided into two parts, the control area and the modulated area. The modulated area was outlined by a yellow dotted box. Simulated probes were placed in each of the two parts to trace and visualize the spatiotemporal evolution of CSD. CSD waves were evoked in the center of the cortex.</p

Additional file 2 of Cortical spreading depression induces propagating activation of the thalamus ventral posteromedial nucleus in awake mice

Additional file 2. The dynamic fluorescence changes of contralateral VPM neuronal activity during CSD in awake mice. No significant activation of VGluT2 neurons was observed in the VPM after CSD induction in the contralateral cortex. The changed fluorescence signal was highly correlated with the motion of mice

List of the parameters used in this study.

<p>“Testing*” means the <i>F</i> value may be changed in the range of (0,1] among different simulations.</p