Sawtooth oscillations were investigated using an electron cyclotron emission imaging diagnostic technique on the HT-7 tokamak. High-order harmonic modes are observed in sawtooth precursors. They cause sharp pressure points, leading to the occurrence of reconnection events at more than one place, and which are not preferential on the low field side of the q ∼ 1 radius at low density. The reconnection proceeds in two stages. In the first stage, a weak reconnection happens which is characterized by a slow emergence of a small amount of heat and particles through the finite openings. Subsequently, in the second stage, most of the remaining heat and particles in the core escape outward. The observations at low density indicate that high-order harmonic modes are responsible for the secondary reconnection stage, which has seldom been mentioned in reconnection model. The characteristics of the modes are then described by investigating a large number of sawteeth oscillations with different densities and qa values. It is found that when the density increases above a threshold at qa = 3.3, the m/n = 1/1 mode amplitude significantly exceeds its harmonics. The threshold decreases as qa increases.
We measure the current?voltage (I?V) characteristics for the single crystal of Tl0.4K0.41Fe1.71Se2 with the superconducting transition temperature (TC) around 30.5 K, under a 10 T magnetic field applied perpendicular and parallel to the ab plane. We find that the shapes of the I?V isotherms are very different from the description by the vortex-glass (VG) model. Combining theoretical calculations and analysis of the ?H?ab?T and ?H?ab?T data, we give an explicit discussion over the suitability of the VG model for the A0.8Fe2Se2 superconductors, and point out the possibility of the material acting as a convenient platform for re-examination and further study of the complex vortex behaviors in the layered superconductors.
Yin and Yang are the two counter-balancing aspects in ancient Chinese philosophy. In traditional Chinese medicine, Yin deficiency syndrome (YDS) is a common sub-health state with complex causes. While the syndrome may be treated to various degrees of effectiveness with traditional Chinese medicine, efficient modern methods are yet to be developed for diagnosing and treating the YDS. Here we performed a metabolomics study on YDS in rats. Serum metabolites in rats were analyzed using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) method to identify potential biomarkers for YDS. The rats were divided randomly into the healthy control group, the untreated YDS group, and the anemarrhena treated YDS group. Compared with the control group, significant increase in the metabolites such as dihydrotestosterone (DHT) and 5β-DHT, 4-imidazolone-5-propanoate, 4-(L-alanin-3-yl)-2-hydroxy-cis,cis-muconate 6-semialdehyde, and 5-(L-alanin-3-yl)-2-hydroxy-cis,cis-muconate 6-semialdehyde were observed in the serum of untreated YDS group, which returned to normal in the anemarrhena treated group. Therefore, these metabolites may serve as potential biomarkers for YDS, and may facilitate the diagnosis and treatment of YDS.
The transport property () and flux motion together with the superconductivity of Fe Se2 single crystals are studied. In the transport measurement, contrasting behavior is observed under two different magnetic field orientations, i.e., and , which is ascribed to different vortex configurations. In the flux motion study, the tail of the well fits the description of the vortex-glass (VG) critical behavior, which is confirmed by VG scaling. The strong pinning nature of FeSe2 implies great sustainability under high magnetic fields and the potential for practical application of the system. The relation under Tc follows Arrhenius thermally activated flux flow (TAFF) behavior. The existence of a crossover behavior in a magnetic field is discovered via the magnetic dependence of the effective pinning barrier, which is related to the change in pinning strength of the point defects and the entanglements of the flux lines. Finally, a vortex phase diagram is proposed based on the evolution of upper critical field and other dynamic characteristics.
Corneal neovascularization (CoNV) can cause abnormal blood vessels to grow in the transparent cornea, leading to various sight-threatening eye diseases. MicroRNAs are known to play essential roles in the regulation of numerous biological functions. We try to clarify the role of a specific microRNA, miR‑497, which has been shown to regulate the growth of tumor cells and angiogenesis on the basis of available data. However, the association between miR-497 and vascularized cornea remains unclear. Therefore, it is urgently needed to understand the molecular mechanism of miR497 in the progress of corneal neovascularization. Animal model of CoNV was established in wildtype (WT) C57BL/6 mice, CRISPR/Cas9 mediated miR-497 knockout (KO) and overexpressed (TG) C57BL/6 mice. MiR-497, expressed in corneas, was actively involved in alkali burn-induced corneal neovascularization via targeting STAT3 and negatively regulating its expression, attenuating macrophage infiltration and M2 polarization. Knockdown of miR-497 enhanced the formation of corneal angiogenesis through targeting STAT3 and facilitating its expression, promoting recruitment of macrophages, while overexpression of miR-497 restrained blood vessel sprouting via regulating downstream STAT3 and VEGFA expression, reducing macrophage activation and inhibiting M2 polarization. Moreover, miR-497 knockout-mediated damage effect can be rescued through the inhibition of STAT3 signaling. Mechanically, miR-497 might serve as a potential strategy for pathological corneal neovascularization via macrophage through the IL-6/STAT3/VEGFA signaling pathway.
The transport and thermoelectric properties together with annealing of the new layered Bi-chalcogenide LaOBiHgS3 are studied. On the transport part, the insulating behavior of the as-grown sample is evidently depressed by post annealing. A hump-like abnormality appears around 170 K. The thermoelectric performance of the sample is observably improved by the annealing, mainly because of the enhanced electrical conductance. The present results suggest that the physical properties of LaOBiHgS3 are sensitive to post annealing and the possible micro adjustments that follow, indicating the layered Bi-chalcogenide family to be an ideal platform for designing novel functional materials.
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