PACS 64.70.Nd -Structural transitions in nanoscale materials PACS 64.70.D--Solid-liquid transitions PACS 61.46.Df -Structure of nanocrystals and nanoparticles ("colloidal" quantum dots but not gate-isolated embedded quantum dots)Abstract -The size effect of materials on the phase structure has been proved by many experiments, and here for the first time, we proposed a size-temperature phase diagram of gallium (Ga). We found that liquid Ga as well as its solid-liquid phase transition (PT) is size dependent. This PT phenomenon was successfully explained in terms of nucleation theory. The size-temperature phase diagram offered a universal phenomenological explanation for the sizerelated phase selection of Ga. This finding would enrich the general knowledge about the new phenomena induced by the finite-size effect.

Submicrometer-sized Ga particles were dispersed in polymethylmethacrylate (PMMA) matrix by an ultrasonic vibration and sedimentation method. The solid phase transition from γ-Ga to δ-Ga and its Ga particle size dependence were studied by means of differential scanning calorimeter measurements. It was shown that a solid-solid phase transition corresponding to the [Formula: see text]-Ga one happened in Ga particles upon cooling. Moreover, the ratio of the particles undergoing the solid phase transition to all particles increases with decrease of the particle size.

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Nowadays, detecting fetal ECG using abdominal signal is a commonly used method, but fetal ECG signal will be affected by maternal ECG. Current FECG extraction algorithms are mainly aiming at multiple channels signal. They often assume there is only one fetus and did not consider multiple births. This paper proposed a single channel blind source separation (SCBSS) algorithm based on source number estimation using multi-algorithm fusion to process single abdominal signal. The method decomposed collected single channel signal into multiple intrinsic mode function (IMF) utilizing Empirical Mode Decomposition (EMD), mapping single channel into multiple channels. Four multiple channel source number estimation (MCSNE) methods (Bootstrap, Hough, AIC and PCA) were weighting fused to estimate accurate source number and the particle swarm optimization algorithm (PSO) was employed to determine weighted coefficient. According to source number and IMF, nonnegative matrix was constructed and nonnegative matrix factorization (NMF) was employed to separate mixed signals. Experiments used single channel signal mixed by four man-made signals and single channel ECG mixed by two to verify the proposed algorithm. Results showed that the proposed algorithm could determine number of independent signal in single acquired signal. FECG could be extracted from single channel observed signal and the algorithm can be used to solve separation of MECG and FECG.

Background: Hydrogen peroxide (H2O2)-induced oxidative stress has been demonstrated to induce afterdepolarizations and triggered activities in isolated myocytes, but the underlying mechanisms remain not fully understood. We aimed to explore whether protein kinase C (PKC) activation plays an important role in oxidative stress-induced afterdepolarizations. Methods: Action potentials and ion currents of isolated rabbit cardiomyocytes were recorded using the patch clamp technique. H2O2 (1 mM) was perfused to induce oxidative stress and the specific classical PKC inhibitor, Gö 6983 (1 μM), was applied to test the involvement of PKC. Results: H2O2 perfusion prolonged the action potential duration and induced afterdepolarizations. Pretreatment with Gö 6983 prevented the emergence of H2O2-induced afterdepolarizations. Additional application of Gö 6983 with H2O2 effectively suppressed H2O2-induced afterdepolarizations. H2O2 increased the late sodium current (INa,L) (n = 7, p < 0.01) and the L-type calcium current (ICa,L) (n = 5, p < 0.01), which were significantly reversed by Gö 6983 (p < 0.01). H2O2 also increased the transient outward potassium current (Ito) (n = 6, p < 0.05). However, Gö 6983 showed little effect on H2O2-induced enhancement of Ito. Conclusions: H2O2 induced afterdepolarizations via the activation of PKC and the enhancement of ICa,L and INa,L. These results provide evidence of a link between oxidative stress, PKC activation and afterdepolarizations.

In this paper, ZnGa2O4 hierarchical nanostructures with comb-like morphology are fabricated by a simple two-step chemical vapor deposition (CVD) method: first, the Ga2O3 nanowires were synthesized and employed as templates for the growth of ZnGa2O4 nanocombs; then, the as-prepared Ga2O3 nanowires were reacted with ZnO vapor to form ZnGa2O4 nanocombs. Before the reaction, the Au nanoparticles were deposited on the surfaces of Ga2O3 nanowires and used as catalysts to control the teeth growth of ZnGa2O4 nanocombs. The as-prepared ZnGa2O4 nanocombs were highly crystallized with cubic spinel structure. From the photoluminescence (PL) spectrum, a broad band emission in the visible light region was observed of as-prepared ZnGa2O4 nanocombs, which make it promising application as an optical material.

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