As a new carbon allotrope, the recently fabricated graphdiyne has attracted much attention due to its interesting two-dimensional character. Here we demonstrate by multiscale computations that, ...unlike graphene, graphdiyne has a natural band gap, and simultaneously possess high electrical conductivity, large Seebeck coefficient, and low thermal conductivity. At a carrier concentration of 2.74×1011cm−2 for holes and 1.62×1011cm−2 for electrons, the room temperature ZT value of graphdiyne can be optimized to 3.0 and 4.8, respectively, which makes it an ideal system to realize the concept of “phonon-glass and electron-crystal” in the thermoelectric community.
ABSTRACT In this paper, multiwavelength data are compiled for a sample of 1425 Fermi blazars to calculate their spectral energy distributions (SEDs). A parabolic function, is used for SED fitting. ...Synchrotron peak frequency ( ), spectral curvature (P1), peak flux ( ), and integrated flux ( ) are successfully obtained for 1392 blazars (461 flat-spectrum radio quasars FSRQs, 620 BL Lacs BLs, and 311 blazars of uncertain type BCUs; 999 sources have known redshifts). Monochromatic luminosity at radio 1.4 GHz, optical R band, X-ray at 1 keV and γ-ray at 1 GeV, peak luminosity, integrated luminosity, and effective spectral indices of radio to optical ( ) and optical to X-ray ( ) are calculated. The "Bayesian classification" is employed to log in the rest frame for 999 blazars with available redshift, and the results show that three components are enough to fit the log distribution; there is no ultra-high peaked subclass. Based on the three components, the subclasses of blazars using the acronyms of Abdo et al. are classified, and some mutual correlations are also studied. Conclusions are finally drawn as follows: (1) SEDs are successfully obtained for 1392 blazars. The fitted peak frequencies are compared with common sources from available samples. (2) Blazars are classified as low synchrotron peak sources if log , intermediate synchrotron peak sources if , and high synchrotron peak sources if . (3) Gamma-ray emissions are strongly correlated with radio emissions. Gamma-ray luminosity is also correlated with synchrotron peak luminosity and integrated luminosity. (4) There is an anticorrelation between peak frequency and peak luminosity within the whole blazar sample. However, there is a marginally positive correlation for high synchrotron peak BL Lacs (HBLs), and no correlations for FSRQs or low synchrotron peak BL Lacs (LBLs). (5) There are anticorrelations between the monochromatic luminosities (γ-ray and radio bands) and the peak frequency within the whole sample and BL Lacs. (6) The optical to X-ray ( ) and radio to optical ( ) spectral indices are strongly anticorrelated with peak frequency (log ) within the whole sample, but the correlations for subclasses of FSRQs, LBLs, and HBLs are different.
A composite coating of N-doped graphene quantum dots (N-GQDs)/polymethyltrimethoxysilane (PMTMS) is prepared on the surface of AZ91D magnesium alloy via electrodeposition and subsequent silane ...treatment. The microstructure of the N-GQDs/PMTMS composite coating is characterized by field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The corrosion resistance performance is investigated by electrochemical impedance spectroscopy (EIS) and immersion test in NaCl solution (3.5 wt%). The N-GQDs/PMTMS composite coating exhibits a significant enhancement of corrosion resistance due to the chemical bonding of N-GQDs coating with Mg substrate and PMTMS coating. The formation mechanisms and nature of the corrosion resistance of the N-GQDs/PMTMS coating are discussed.
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Glycolysis is critical for cancer stem cell reprogramming; however, the underlying regulatory mechanisms remain elusive. Here, we show that pyruvate dehydrogenase kinase 1 (PDK1) is enriched in ...breast cancer stem cells (BCSCs), whereas depletion of PDK1 remarkably diminishes ALDH
subpopulations, decreases stemness-related transcriptional factor expression, and inhibits sphere-formation ability and tumor growth. Conversely, high levels of PDK1 enhance BCSC properties and are correlated with poor overall survival. In mouse xenograft tumor, PDK1 is accumulated in hypoxic regions and activates glycolysis to promote stem-like traits. Moreover, through screening hypoxia-related long non-coding RNAs (lncRNAs) in PDK1-positive tissue, we find that lncRNA H19 is responsible for glycolysis and BCSC maintenance. Furthermore, H19 knockdown decreases PDK1 expression in hypoxia, and ablation of PDK1 counteracts H19-mediated glycolysis and self-renewal ability in vitro and in vivo. Accordingly, H19 and PDK1 expression exhibits strong correlations in primary breast carcinomas. H19 acting as a competitive endogenous RNA sequesters miRNA let-7 to release Hypoxia-inducible factor 1α, leading to an increase in PDK1 expression. Lastly, aspirin markedly attenuates glycolysis and cancer stem-like characteristics by suppressing both H19 and PDK1. Thus, these novel findings demonstrate that the glycolysis gatekeeper PDK1 has a critical role in BCSC reprogramming and provides a potential therapeutic strategy for breast malignancy.
Using combined data from the Relativistic Heavy Ion and Large Hadron Colliders, we constrain the shear and bulk viscosities of quark-gluon plasma (QGP) at temperatures of ∼ 150 – 350 MeV . We use ...Bayesian inference to translate experimental and theoretical uncertainties into probabilistic constraints for the viscosities. With Bayesian model averaging we propagate an estimate of the model uncertainty generated by the transition from hydrodynamics to hadron transport in the plasma's final evolution stage, providing the most reliable phenomenological constraints to date on the QGP viscosities.
Gas hydrate formation experiments were performed using methane in the presence of tetrahydrofuran (THF) in aqueous solution in a transparent bubble column in which a single pipe or a sintered plate ...was used to produce bubbles. The mole fraction of THF in aqueous solution was fixed at 6%. The hydrate formation kinetic behaviors on the surface of the rising bubble, the mechanical stability of hydrate shell formed on the surface of the bubble, the interactions among the bubbles with hydrate shell were observed and investigated morphologically. The rise velocities of individual bubbles with hydrate shells of different thickness and the consumption rates of methane gas were measured. A kinetic model was developed to correlate the experimentally measured gas consumption rate data. It was found that the hydrate formation rate on the surface of the moving bubble was high, but the formed hydrate shell was not very easy to be broken up. The bubbles with hydrate shells tended to agglomerate rather than merge into bigger bubble. This kind of characteristic of hydrate shell hindered the further formation of hydrate and led to the lower consumption rate of methane. The consumption rate of methane was found to increase with the decrease of temperature or increase of pressure. The increase of gas flux led to a linear increase in consumption rate of methane. It was demonstrated that the developed kinetic model could be used to correlate the consumption rate satisfyingly.
Summary
CircRNAs exert gene regulatory effects by sequestering target microRNAs (miRNAs) and play a vital role in the onset and development of disease. Until recently, little has been known about the ...expression, regulation and biological function of circRNAs in both health and chronic hepatitis B (CHB).To identify hepatic circRNAs associated with CHB, we performed RNA sequencing using liver biopsies from untreated CHB patients and controls. We then established a bioinformatics pipeline for identification of CHB‐associated circRNAs and in silico analysis of the circRNA‐miRNA‐mRNA pathways. We used quantitative reverse transcription polymerase chain reaction (qRT‐PCR) to confirm these results. The profiles of hepatic circRNA expression were significantly different in CHB compared with controls, with a total of 99 dysregulated circRNAs identified to be correlated with CHB. Computational analysis of the circRNA‐miRNA‐mRNA pathways revealed a large number of miRNAs (665), which were putatively targeted by the differentially expressed hepatic circRNAs. Interestingly, four of the predicted CHB‐related circRNA‐miRNA‐mRNA pathways were found to be involved in the pathogenesis of HBV infection and progression of HBV‐associated liver disease. Among these pathways, regression analysis of gene expression revealed a strong positive correlation between hsa_circ_0000650 and TGFβ2 and a negative correlation between hsa_circ_0000650 and miR‐6873‐3p, which hinted that hsa_circ_0000650 interacted with TGFβ2 mediated by miR‐6873‐3p. This study firstly demonstrates that patients with CHB present different profiles of hepatic circRNAs and circRNA/miRNA interactions. Thus, circRNAs have promise as novel mechanisms underlying the pathogenesis and progression of CHB.
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