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Although dielectric energy-storing devices are frequently used in high voltage level, the fast growing on the portable and wearable electronics have been increasing the demand on the energy-storing devices at finite electric field strength. This paper proposes an approach on enhancing energy density under low electric field through compositionally inducing tricriticality in Ba(Ti,Sn)O3 ferroelectric material system with enlarged dielectric response. The optimal dielectric permittivity at tricritical point can reach to εr = 5.4 × 104, and the associated energy density goes to around 30 mJ/cm3 at the electric field of 10 kV/cm, which exceeds most of the selected ferroelectric materials at the same field strength. The microstructure nature for such a tricritical behavior shows polarization inhomogeneity in nanometeric scale, which indicates a large polarizability under external electric field. Further phenomenological Landau modeling suggests that large dielectric permittivity and energy density can be ascribed to the vanishing of energy barrier for polarization altering caused by tricriticality. Our results may shed light on developing energy-storing dielectrics with large permittivity and energy density at low electric field.

A single microRNA (miRNA) can regulate expression of multiple proteins, and expression of an individual protein may be controlled by numerous miRNAs. This regulatory pattern strongly suggests that synergistic effects of miRNAs play critical roles in regulating biological processes. miR-9 and miR-124, two of the most abundant miRNAs in the mammalian nervous system, have important functions in neuronal development. In this study, we identified the small GTP-binding protein Rap2a as a common target of both miR-9 and miR-124. miR-9 and miR-124 together, but neither miRNA alone, strongly suppressed Rap2a, thereby promoting neuronal differentiation of neural stem cells (NSCs) and dendritic branching of differentiated neurons. Rap2a also diminished the dendritic complexity of mature neurons by decreasing the levels of pAKT and pGSK3β. Our results reveal a novel pathway in which miR-9 and miR-124 synergistically repress expression of Rap2a to sustain homeostatic dendritic complexity during neuronal development and maturation.

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Biologically inspired dry adhesion has recently become a research hot topic because of its practical significance in scientific research and instrumental technology. Yet, most of the current studies merely focus on borrowing the concept from some finer biological contact elements but lose sight of the foundation ones that play an equally important role in the adhesion functionality. Inspired by the bending behavior of the flexible foundation element of a gecko (lamellar skin) in attachment motion, in this study, a new type of dry adhesive structure was proposed, wherein a mushroom-shaped micropillar array behaving as a strongly adhesive layer was engineered on a discretely supported thin film. We experimentally observed and analytically modeled the structural deformation and found that the energy penalty could be largely reduced because of the partial shift from pillar bending to film bending. Such behavior is very analogous in functionality to the lamellar skin in a gecko's pads and is helpful in effectively limiting the damage of the contact interface, thus generating enhanced adhesion even on a rough surface.

Obesity and metabolic syndrome (MS) associated with excess calorie intake has become a great public health concern worldwide. L-arabinose, a naturally occurring plant pentose, has a promising future as a novel food ingredient with benefits in MS; yet the mechanisms remain to be further elucidated. Gut microbiota is recently recognized to play key roles in MS. Molecular hydrogen, an emerging medical gas with reported benefits in MS, can be produced and utilized by gut microbes. Here we show oral L-arabinose elicited immediate and robust release of hydrogen in mice in a dose-and-time-dependent manner while alleviating high-fat-diet (HFD) induced MS including increased body weight especially fat weight, impaired insulin sensitivity, liver steatosis, dyslipidemia and elevated inflammatory cytokines. Moreover, L-arabinose modulated gene-expressions involved in lipid metabolism and mitochondrial function in key metabolic tissues. Antibiotics treatment abolished L-arabinose-elicited hydrogen production independent of diet type, confirming gut microbes as the source of hydrogen. q-PCR of fecal 16S rDNA revealed modulation of relative abundances of hydrogen-producing and hydrogen-consuming gut microbes as well as probiotics by HFD and L-arabinose. Our data uncovered modulating gut microbiota and hydrogen yield, expression of genes governing lipid metabolism and mitochondrial function in metabolic tissues is underlying L-arabinose's benefits in MS.Nutrients 2019, 11, 3054 2 of 29 non-caloric sugars have become one of the rising stars among nutraceuticals with great potential in anti-MS application with reported benefits in both animal experiments and human studies.L-arabinose, a naturally occurring constituent of plant polysaccharides, usually extracted from vegetable gum, corn straw or beet, has gained considerable attention for its potential in anti-MS application recently. L-arabinose administration for 6 weeks reduces body weight, blood pressure, blood glucose, triglycerides, total cholesterol, serum insulin, serum TNF-α and serum leptin; and increases hepatic CPT1 and PDK4 mRNA level while decreases hepatic ACCα mRNA level in high-carbohydrate-high-fat-diet induced MS rats [1]. Polysaccharide from corn silk containing L-arabinose showed hypoglycemic and hypolipidemic effects on diabetic mice induced by high-fat-diet (HFD) and streptozotocin injection [2]. One mechanism underlying L-arabinose's benefits in MS has been demonstrated as directly inhibiting intestinal sucrase activity both in vitro and in human [3], which explains why L-arabinose effectively lower blood glucose and insulin level with ingestion of high-sucrose food or beverages but is unable to account for L-arabinose's benefits in MS in general. Therefore, more studies are urgently called to illuminate the mechanisms underlying L-arabinose's effects in HFD models, considering fat being a major source of energy intake in reality.Gut microbiota has been recognized to play a pathogenic role in the development of MS in both humans and animal models in the last...