Two-dimensional electron-gas-like charge transport at magnetic Heusler alloy-SrTiO3_3 interface

We report remarkably low residual resistivity, giant residual resistivity ratio, free-electron-like Hall resistivity and high mobility ($\approx$ 10$^4$ cm$^2$V$^{-1}$s$^{-1}$) charge transport in epitaxial films of Co$_2$MnSi and Co$_2$FeSi grown on (001) SrTiO$_3$. This unusual behavior is not observed in films deposited on other cubic oxide substrates of comparable lattice parameters. The scaling of the resistivity with thickness of the films allow extraction of interface conductance, which can be attributed to a layer of oxygen vacancies confined within 1.9 nm of the interface as revealed by atomically resolved electron microscopy and spectroscopy. The high mobility transport observed here at the interface of a fully spin polarized metal is potentially important for spintronics applications

The Determination of Degradation Products of Lewisite and/or Mustard Gas in Water by High Performance Liquid Chromatography

Lewisite (L) and mustard gas (HD) are highly toxic vesicant warfare agents that are very sparingly soluble in water and thereby converted quantitatively to the stable and soluble degradation products 2-chlorovinylarsonous acid (CVAA), 2-chloro vinylarsonic acid (CVAOA), 2,2’-dihydroxyethyl sulphide and 2,2’-dichlorodiethyl sulphoxide. A new method based on reversed-phase high performance liquid chromatography (RP-HPLC) has been developed for the simultaneous detection of CVAOA, CVAA, 2,2’-dichlorodiethyl sulphoxide, 2,2’-dihydroxyethyl sulphide. The effects of eluent and pH on the separation efficiency were studied. UV spectra of CVAOA, CVAA, 2,2’-dichlorodiethyl sulphoxide and 2,2’-dihydroxyethyl sulphide were recorded. Good separation was achieved by HPLC using a 250 × 4.6 mm column with 5 μm ODS C18 after optimization of all relevant parameters. The calibration curves ofCVAOA,CVAA, 2,2’-dichlorodiethyl sulphoxide and 2,2’-dihydroxyethyl sulphide showed high linearity over a concentration range of 5–500, 2–500, 5–500, 50–1000 mg L–1, respectively. The detection limits at a signal-to-noise ratio of 3 were 0.001, 0.2, 2, 20mgL–1. The method may be beneficial for studying the distribution of lewisite-and/or mustard gas and their degradation products in the environment.Keywords: High performance liquid chromatography, 2-chlorovinylarsonic acid, -chlorovinylarsonous acid, 2,2’-dichlorodiethylsulphoxide, 2,2’-dihydroxyethyl sulphide

Advances in antitumor effects of NSAIDs

YesIn recent years, the reports on using nonsteroidal anti-inflammatory drugs (NSAIDs) for cancer prevention and treatment have been on the rise. In 2017, the US Preventive Services Working Group issued primary prevention guidelines on the use of NSAIDs, especially aspirin, for cardiovascular disease and colorectal cancer, and formally established the role and status of aspirin in cancer prevention. However, the mechanism of NSAIDs on preventing cancer is still not clear. In this paper, the progress of the application of NSAIDs, especially aspirin, in the prevention and treatment of tumors in recent years is summarized, and new ideas and directions for the follow-up study are also discussed

A Novel YY1-miR-1 Regulatory Circuit in Skeletal Myogenesis Revealed by Genome-Wide Prediction of YY1-miRNA Network

microRNAs (miRNAs) are non-coding RNAs that regulate gene expression post-transcriptionally, and mounting evidence supports the prevalence and functional significance of their interplay with transcription factors (TFs). Here we describe the identification of a regulatory circuit between muscle miRNAs (miR-1, miR-133 and miR-206) and Yin Yang 1 (YY1), an epigenetic repressor of skeletal myogenesis in mouse. Genome-wide identification of potential down-stream targets of YY1 by combining computational prediction with expression profiling data reveals a large number of putative miRNA targets of YY1 during skeletal myoblasts differentiation into myotubes with muscle miRs ranking on top of the list. The subsequent experimental results demonstrate that YY1 indeed represses muscle miRs expression in myoblasts and the repression is mediated through multiple enhancers and recruitment of Polycomb complex to several YY1 binding sites. YY1 regulating miR-1 is functionally important for both C2C12 myogenic differentiation and injury-induced muscle regeneration. Furthermore, we demonstrate that miR-1 in turn targets YY1, thus forming a negative feedback loop. Together, these results identify a novel regulatory circuit required for skeletal myogenesis and reinforce the idea that regulatory circuitries involving miRNAs and TFs are prevalent mechanisms

Control of magnetic anisotropy by orbital hybridization in (La0.67Sr0.33MnO3)n/(SrTiO3)n superlattice

The asymmetry of chemical nature at the hetero-structural interface offers an unique opportunity to design desirable electronic structure by controlling charge transfer and orbital hybridization across the interface. However, the control of hetero-interface remains a daunting task. Here, we report the modulation of interfacial coupling of (La0.67Sr0.33MnO3)n/(SrTiO3)n superlattices by manipulating the periodic thickness with n unit cells of SrTiO3 and n unit cells La0.67Sr0.33MnO3. The easy axis of magnetic anisotropy rotates from in-plane (n = 10) to out-of-plane (n = 2) orientation at 150 K. Transmission electron microscopy reveals enlarged tetragonal ratio > 1 with breaking of volume conservation around the (La0.67Sr0.33MnO3)n/(SrTiO3)n interface, and electronic charge transfer from Mn to Ti 3d orbitals across the interface. Orbital hybridization accompanying the charge transfer results in preferred occupancy of 3d3z2-r2 orbital at the interface, which induces a stronger electronic hopping integral along the out-of-plane direction and corresponding out-of-plane magnetic easy axis for n = 2. We demonstrate that interfacial orbital hybridization in superlattices of strongly correlated oxides may be a promising approach to tailor electronic and magnetic properties in device applications

On a Stochastic Wave Equation Driven by a Non-Gaussian Levy Process

This paper investigates a damped stochastic wave equation driven by a non-Gaussian Levy noise. The weak solution is proved to exist and be unique. Moreover we show the existence of a unique invariant measure associated with the transition semigroup under mild conditions.Comment: 17 page

Electronic correlations in the iron pnictides

In correlated metals derived from Mott insulators, the motion of an electron is impeded by Coulomb repulsion due to other electrons. This phenomenon causes a substantial reduction in the electron's kinetic energy leading to remarkable experimental manifestations in optical spectroscopy. The high-Tc superconducting cuprates are perhaps the most studied examples of such correlated metals. The occurrence of high-Tc superconductivity in the iron pnictides puts a spotlight on the relevance of correlation effects in these materials. Here we present an infrared and optical study on single crystals of the iron pnictide superconductor LaFePO. We find clear evidence of electronic correlations in metallic LaFePO with the kinetic energy of the electrons reduced to half of that predicted by band theory of nearly free electrons. Hallmarks of strong electronic many-body effects reported here are important because the iron pnictides expose a new pathway towards a correlated electron state that does not explicitly involve the Mott transition.Comment: 10 page