875 research outputs found
Echoes of Inflationary First-Order Phase Transitions in the CMB
Cosmological phase transitions (CPTs), such as the Grand Unified Theory (GUT)
and the electroweak (EW) ones, play a significant role in both particle physics
and cosmology. In this letter, we propose to probe the first-order CPTs, by
detecting gravitational waves (GWs) which are generated during the phase
transitions through the cosmic microwave background (CMB). If happened around
the inflation era, the first-order CPTs may yield low-frequency GWs due to
bubble dynamics, leaving imprints on the CMB. In contrast to the nearly
scale-invariant primordial GWs caused by vacuum fluctuation, these
bubble-generated GWs are scale dependent and have non-trivial B-mode spectra.
If decoupled from inflaton, the EWPT during inflation may serve as a probe for
the one after reheating where the baryon asymmetry could be generated via EW
baryogenesis (EWBG). The CMB thus provides a potential way to test the
feasibility of the EWBG, complementary to the collider measurements of Higgs
potential and the direct detection of GWs generated during EWPT.Comment: 5+6 pages, 4 figures. V2 changed title, added one figure about
constraints of Planck2015+BICEP2/Keck data, added references and removed
appendix. Accepted by PL
Identifying Crypto Addresses with Gambling Behaviors: A Graph Neural Network Approach
The development of blockchain technology has brought prosperity to the cryptocurrency market and has made the blockchain platform a hotbed of crimes. As one of the most rampant crimes, crypto gambling has more high risk of illegal activities due to the lack of regulation. As a result, identifying crypto addresses with gambling behaviors has emerged as a significant research topic. In this work, we propose a novel detection approach based on Graph Neural Networks named CGDetector, consisting of Graph Construction, Subgraph Extractor, Statistical Feature Extraction, and Gambling Address Classification. Extensive experiments of large-scale and heterogeneous Ethereum transaction data are implemented to demonstrate that our proposed approach outperforms state-of-the-art address classifiers of traditional machine learning methods. This work makes the first attempt to detect suspicious crypto gambling addresses via Graph Neural Networks by all EVM-compatible blockchain systems, providing new insights into the field of cryptocurrency crime detection and blockchain security regulation
Inducible miR-145 expression by HIF-1a protects cardiomyocytes against apoptosis via regulating SGK1 in simulated myocardial infarction hypoxic microenvironment
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 Background: Myocardial infarction (MI) is partly due to myocardial cell damage caused by hypoxia. MicroRNAs (miRNAs) have been proved to be closely related to the development and progression of many cardiovascular diseases. This study investigated the role of miR-145 in cardiomyocytes under hypoxic condition.
Methods: The quantitative real-time polymerase chain reaction (qRT-PCR) was performed to test miR-145 expression in H9c2 cells with hypoxia-inducible factor (HIF)-a abnormal expression under hypoxic condition. The 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyltetrazolium bromide (MTT), TranÂswell assay and flow cytometry were used to investigate the effects of miR-145 on cell viability, migration and apoptosis under normoxic or hypoxic condition, respectively. Meanwhile, reactive oxygen species (ROS) content in hypoxic H9c2 cells was analyzed. Western blotting was used to explore the potential mechanism of miR-145 protective effects on cardiomyocytes. Expression levels of miR-145 and SGK1 in rat MI model were also assessed.
Results: Results showed that miR-145 was upregulated in H9c2 and HL-1 cells under hypoxic condiÂtion, which was promoted by HIF-1a. MiR-145 overexpression enhanced cell viability and migration under normoxic condition. Under hypoxic condition, miR-145 overexpression promoted cell viability, inhibited apoptosis and ROS activity. Western blotting results proved that miR-145 overexpression inhibited the activation of apoptotic related factors, and promoted activation of PI3K/AKT signaling pathway via SGK1 upregulation. Expression levels of miR-145 and SGK1 were both upregulated in rat MI models.
Conclusions: HIF-1a could induce miR-145 upregulation in hypoxic H9c2 and HL-1 cells. MiR-145 protected H9c2 cells against hypoxic damage. SGK1 upregulation and activated PI3K/AKT may have participated in the protective effects of miR-145 on cardiomyocytes
Characterization of the fertilization independent endosperm (FIE) gene from soybean
Reproduction of angiosperm plants initiates from two fertilization events: an egg fusing with a sperm to form an embryo and a second sperm fusing with the central cell to generate an endosperm. The tryptophan-aspartate (WD) domain polycomb protein encoded by fertilization independent endosperm (FIE) gene, has been known as a repressor of hemeotic genes by interacting with other polycomb proteins, and suppresses endosperm development until fertilization. In this study, one Glycine max FIE (GmFIE) gene was cloned and its expression in different tissues, under cold and drought treatments, was analyzed using both bioinformatics and experimental methods. GmFIE showed high expression in reproductive tissues and was responsive to stress treatments, especially induced by cold. GmFIE overexpression lines of transgenic Arabidopsis were generated and analyzed. Delayed flowering was observed from most transgenic lines compared to that of wild type. Overexpression of GmFIE in Arabidopsis also leads to semi-fertile of the plants.Keywords: Polycomb proteins, fertilization independent endosperm (FIE), Glycine max, Arabidopsis thalian
21-(3-CarboxyÂpropanoÂyl)-11β,17-dihydroxyÂpregn-4-ene-3,20-dione monohydrate
In the title compound, C25H34O8·H2O, the two crylohexane rings adopt chair conformations. In the crystal, the organic molÂecule and the water molÂecule are linked by O—H⋯O hydrogen bonds, generating a three-dimensional network
Preparation of graphene film reinforced CoCrFeNiMn high-entropy alloy matrix composites with strength-plasticity synergy via flake powder metallurgy method
Inspired by the design principle of pearl structure, a bottom-up flake powder self-assembly arrangement strategy, flake powder metallurgy, is used to prepare graphene films (GFs) reinforced CoCrFeNiMn high-entropy alloy (HEA) matrix composites with a pearl laminated structure. Flaky HEA powder was prepared by ball milling method and homogeneously mixed with Ni plated GFs. Vacuum hot-press sintering (VHPS) technique was carried out to solidify the mixed powders to obtain composites with uniform distribution of GFs(Ni) and flaky HEA. The results show that the bottom-up preparation strategy can effectively fabricate bionic laminated HEA matrix composites, and the composites have a distinct pearly laminated structure. The tensile strength of the composites with 5 vol% GFs(Ni) content reached 834.04 MPa, and the elongation reached 26.58 %. The compressive strength in parallel and perpendicular laminar directions reached 2069.66 MPa and 2418.45 MPa at 50 % strain, respectively. The laminated GFs(Ni)/HEA matrix composites possessed excellent strength and maintained good plasticity. In this study, the strengthening and toughening mechanism of the laminated GFs(Ni)/HEA matrix composites is discussed in detail, and the results show that the laminated structure and GFs(Ni) are favorable for the hardening and strengthening of the HEA matrix
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