3,795 research outputs found

    Semi-strict chordality of digraphs

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    Chordal graphs are important in algorithmic graph theory. Chordal digraphs are a digraph analogue of chordal graphs and have been a subject of active studies recently. In this paper we introduce the notion of semi-strict chordal digraphs which form a class strictly between chordal digraphs and chordal graphs. We characterize semi-strict chordal digraphs by forbidden subdigraphs within the cases of locally semicomplete digraphs and weakly quasi-transitive digraphs.Comment: 12 pages, 2 figures. arXiv admin note: text overlap with arXiv:2008.0356

    The Research on Competitive Abilities for Sustainable Development of Small and Medium-sized Textile Enterprises in Shandong Province

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    Under the condition of market competition, the success and the failure of the enterprise management is normally regarded as the result of “superior winning while inferior out”. Yet for the community of theorists and entrepreneurs, what are the reasons leading to the enterprise bankruptcy or successful are important research topics. Among the small and medium-sized enterprises in China, most are loose and innovating slowly in their business management. The lower competitive ability has become the serious barrier for their sustainable development. Comprehensive analysis are made on the positive factors and adverse factors affecting sustainable development of small and medium-sized textile enterprises of Shandong Province according to on-the-spot investigations. How to gain and maintain the continued survival and development ability of the enterprises, and how to enhance competitive ability and realize the sustainable development are analyzed. And three kinds of development strategies are put forward

    Amplification of rotation velocity using weak measurements in Sagnac's interferometer

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    We study the amplification of rotation velocity with the Sagnac interferometer based on the concept of weak-value amplification. By using a different scheme to perform the Sagnac interferometer with the probe in momentum space, we have demonstrated the new weak measure protocol to detect the small rotation velocity by amplifying the phase shift of the Sagnac effect. At the given the maximum incident intensity of the initial spectrum, the detection limit of the intensity of the spectrometer and the accuracy of angular velocity measurement, we can theoretical give the appropriate potselection and the minimum of optical path area before experiment. In addition, we put forward a new optical design to increase the optical path area and decrease the size of the interferometer to overcome the limit of instrument size. Finally, our modified Sagnac's interferometer based on weak measurement is innovative and efficient probing the small rotation velocity signal.Comment: arXiv admin note: text overlap with arXiv:1203.0827 by other author

    Protective effect of liquiritin on corticosterone-induced neurotoxicity in PC12 cells

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    Purpose: To determine the protective effects of liquiritin on corticosterone-induced neurotoxicity in rat pheochromocytoma (PC12) cells.Methods: Neurotoxicity in PC12 cells was induced by different concentrations of corticosterone. Proliferation of PC12 cells was evaluated using CCK8 assay kits, while apoptosis was determined by flow cytometry.Results: The results indicate that corticosterone inhibited the proliferation of PC12 cells time- and dosedependently. The inhibitory effect (0.2 mM) was ameliorated by liquiritin. Furthermore, the cell apoptosis rate and protein level of caspase 3 in PC12 cells induced by corticosterone were ameliorated by liquiritin (1 and 2 mg/mL) treatment. Moreover, the protective effect of liquiritin (2 mg/mL) on corticosterone induced neurotoxicity in PC12 cells was weakened by K252a (the specific TrkB inhibitor) treatment. In addition, the protein level of brain-derived neurotrophic factor (BDNF) and (tyrosine-kinase receptor) TrkB showed a reverse trend to caspase 3.Conclusion: Liquiritin shows protective effects against neurotoxicity induced by corticosterone in PC12 cells, and these effects are exerted via up-regulating BDNF/TrkB signaling.Keywords: Liquiritin, Antidepressant, Corticosterone, Neuroprotection, PC12 cells, BDNF/TrkB signalin

    Regulation of CLC-1 chloride channel biosynthesis by FKBP8 and Hsp90β.

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    Mutations in human CLC-1 chloride channel are associated with the skeletal muscle disorder myotonia congenita. The disease-causing mutant A531V manifests enhanced proteasomal degradation of CLC-1. We recently found that CLC-1 degradation is mediated by cullin 4 ubiquitin ligase complex. It is currently unclear how quality control and protein degradation systems coordinate with each other to process the biosynthesis of CLC-1. Herein we aim to ascertain the molecular nature of the protein quality control system for CLC-1. We identified three CLC-1-interacting proteins that are well-known heat shock protein 90 (Hsp90)-associated co-chaperones: FK506-binding protein 8 (FKBP8), activator of Hsp90 ATPase homolog 1 (Aha1), and Hsp70/Hsp90 organizing protein (HOP). These co-chaperones promote both the protein level and the functional expression of CLC-1 wild-type and A531V mutant. CLC-1 biosynthesis is also facilitated by the molecular chaperones Hsc70 and Hsp90β. The protein stability of CLC-1 is notably increased by FKBP8 and the Hsp90β inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG) that substantially suppresses cullin 4 expression. We further confirmed that cullin 4 may interact with Hsp90β and FKBP8. Our data are consistent with the idea that FKBP8 and Hsp90β play an essential role in the late phase of CLC-1 quality control by dynamically coordinating protein folding and degradation
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