2,654 research outputs found

    4-Tosyl-1-oxa-4-aza­spiro­[4.5]deca-6,9-dien-8-one

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    In the mol­ecule of the title compound, C15H15NO4S, the two six-membered rings are almost parallel to each other [dihedral angle = 1.87 (9)°] and perpendicular to the mean plane through the five-membered ring [dihedral angles of 89.98 (10) and 89.04 (10)°]. The crystal structure is stabilized by inter­molecular C—H⋯O hydrogen-bonding inter­actions

    2,3-Bis(4-ethoxy­phen­yl)quinoxaline

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    The title compound, C24H22N2O2, was prepared by condensation of 1,2-bis­(4-ethoxy­phen­yl)ethane-1,2-dione and 1,2-diamino­benzene. The asymmetric unit contains one half-mol­ecule, close to a twofold axis. The plane of the quinoxaline ring is twisted with respect to the planes of the two ethoxy­phenyl ring systems, exhibiting dihedral angles of 39.95 (9)°. The crystal packing is dominated by weak C—H⋯π inter­actions. No classical hydrogen bonds or stacking inter­actions are observed

    WNT/β-catenin signaling promotes VSMCs to osteogenic transdifferentiation and calcification through directly modulating Runx2 gene expression

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    AbstractArterial medial calcification (AMC) is prevalent in patients with chronic kidney disease (CKD) and contributes to elevated risk of cardiovascular events and mortality. Vascular smooth muscle cells (VSMCs) to osteogenic transdifferentiation (VOT) in a high-phosphate environment is involved in the pathogenesis of AMC in CKD. WNT/β-catenin signaling is indicated to play a crucial role in osteogenesis via promoting Runx2 expression in osteoprogenitor cells, however, its role in Runx2 regulation and VOT remains incompletely clarified. In this study, Runx2 was induced and β-catenin was activated by high-phosphate in VSMCs. Two forms of active β-catenin, dephosphorylated on Ser37/Thr41 and phosphorylated on Ser675 sites, were upregulated by high-phosphate. Activation of β-catenin, through ectopic expression of stabilized β-catenin, inhibition of GSK-3β, or WNT-3A protein, induced Runx2 expression, whereas blockade of WNT/β-catenin signaling with Porcupine (PORCN) inhibitor or Dickkopf-1 (DKK1) protein inhibited Runx2 induction by high-phosphate. WNT-3A promoted osteocalcin expression and calcium deposition in VSMCs, whereas DKK1 ameliorated calcification of VSMCs induced by high-phosphate. Two functional T cell factor (TCF)/lymphoid enhancer-binding factor binding sites were identified in the promoter region of Runx2 gene in VSMCs, which interacted with TCF upon β-catenin activation. Site-directed mutation of each of them attenuated Runx2 response to β-catenin, and deletion or destruction of both of them completely abolished this responsiveness. In the aortic tunica media of rats with chronic renal failure, followed by AMC, Runx2 and β-catenin was induced, and the Runx2 mRNA level was positively associated with the abundance of phosphorylated β-catenin (Ser675). Collectively, our study suggested that high-phosphate may activate WNT/β-catenin signaling through different pathways, and the activated WNT/β-catenin signaling, through direct downstream target Runx2, could play an important role in promoting VOT and AMC

    The Viscoelasticity Model of Corn Straw under the Different Moisture Contents

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    Viscoelastic model of corn straw, based on different moisture contents, is set up to characterise the deformation through three-point bending test. The model contains a linear elastic element, a damping element, and a nonlinear elastic element. The parameters of the model are determined according to the features of three-point bending test curve and characteristic of the model. The relationships between mechanical properties, energy absorption behavior of corn stalk, and moisture content have been, respectively, analysed. And regression analysis and curve fitting have been conducted based on various parameters and moisture contents with Matlab. These parameters provide the basis for straw crushing equipment design

    Calculation of the Four-Quark Condensates in the QCD Motivated Nambu-Jona- Lasinio Model

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    The four-quark condensates appearing in QCD sum rule are calculated nonperturbatively in a realistic QCD motivated extended Nambu-Jona-Lasinio model. The calculation is in the framework of the effective potential for local composite operators up to next-to-the-leading order in the 1/N expansion in which the non-factorized parts of the condensates are included. We show in this paper the possibility of explaining the phenomenological enhancement factor  κ=2.4 ~\kappa=2.4~, needed for fitting the data in the factorization approximation, as the contribution of the non-factorized parts of the four- quark condensates.Comment: 12 pages, TUIMP-TH-94/5

    2-(Hy­droxy­meth­yl)pyridin-3-ol

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    In the crystal structure of the title compound, C6H7NO2, the mol­ecules are are linked by inter­molecular O—H⋯N and O—H⋯O hydrogen bonds; π–π stacking is observed between parallel pyridine rings of adjacent mol­ecules [centroid-to-centroid distance = 3.7649 (12) Å]

    2-[(4,6-Dimeth­oxy­pyrimidin-2-yl)­oxy]benzaldehyde

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    In the title compound, C13H12N2O4, the dihedral angle between the benzene and pyrimidine rings is 55.57 (13)°. The carbonyl group and the two methoxyl groups are approximately coplanar with the benzene ring and pyrimidine ring; the C—C—C—O, C—O—C—N and C—O—C—C torsion angles being −6.1 (5), −4.8 (4) and 179.9 (3)°, respectively. In the crystal, mol­ecules are linked via C—H⋯O inter­actions, forming chains propagating along [110]
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