2,692 research outputs found
catena-Poly[[(2,2′-bipyridine)copper(II)]-μ-5-tert-butylisophthalato]
In the crystal structure of the title polymeric compound, [Cu(C12H12O4)(C10H8N2)]n, the asymmetric unit consists of one CuII ion, one 5-tert-butylisophthalate (tbip) and one 2,2′-bipyridine (bpy) ligand. The copper(II) ion is four-coordinated by two N atoms from bipy and two O atoms from two tbip ligands, leading to a distorted tetrahedral coordination. Each tbip ligand adopts a bis-monodentate coordination mode to connect two symmetry-related copper(II) ions, so forming a zigzag polymer chain parallel to [001]. The tert-butyl methyl groups are disordered over two positions with occupancies of 0.506 (6)/0.494 (6
Fucoxanthin Enhances Cisplatin-Induced Cytotoxicity via NFκB-Mediated Pathway and Downregulates DNA Repair Gene Expression in Human Hepatoma HepG2 Cells
Cisplain, a platinum-containing anticancer drug, has been shown to enhance DNA repair and to inhibit cell apoptosis, leading to drug resistance. Thus, the combination of anticancer drugs with nutritional factors is a potential strategy for improving the efficacy of cisplatin chemotherapy. In this study, we investigated the anti-proliferative effects of a combination of fucoxanthin, the major non-provitamin A carotenoid found in Undaria Pinnatifida, and cisplatin in human hepatoma HepG2 cells. We found that fucoxanthin (1–10 μΜ) pretreatment for 24 h followed by cisplatin (10 μΜ) for 24 h significantly decreased cell proliferation, as compared with cisplatin treatment alone. Mechanistically, we showed that fucoxanthin attenuated cisplatin-induced NFκB expression and enhanced the NFκB-regulated Bax/Bcl-2 mRNA ratio. Cisplatin alone induced mRNA expression of excision repair cross complementation 1 (ERCC1) and thymidine phosphorylase (TP) through phosphorylation of ERK, p38 and PI3K/AKT pathways. However, fucoxanthin pretreatment significantly attenuated cisplatin-induced ERCC1 and TP mRNA expression, leading to improvement of chemotherapeutic efficacy of cisplatin. The results suggest that a combined treatment with fucoxanthin and cisplatin could lead to a potentially important new therapeutic strategy against human hepatoma cells
Bis(4-aminobenzenesulfonato)triaquabis(1,10-phenanthroline)neodymium(III) nitrate tetrahydrate
The title complex, [Nd(C6H6NO3S)2(C12H8N2)2(H2O)3]NO3·4H2O, comprises a mononuclear cation, an NO3
− anion and two uncoordinated water molecules; the NdIII cation, one coordinated water molecule, and the NO3
− anion each lie on a twofold axis of symmetry. The NdIII ion exhibits an NdN4O5 coordination environment comprising two O atoms of two monodentate 4-aminobenzenesulfonato ligands, four N atoms of the bidentate 1,10-phenanthroline ligands, and three water-O atoms. The coordination geometry is based on a tricapped triangular-prismatic arrangement. The components are consolidated into a three-dimensional network via O—H⋯O, O—H⋯N and N—H⋯O hydrogen-bonding interaction
Bis(4-aminobenzenesulfonato)triaquabis(1,10-phenanthroline)neodymium(III) nitrate tetrahydrate
The title complex, [Nd(C6H6NO3S)2(C12H8N2)2(H2O)3]NO3·4H2O, comprises a mononuclear cation, an NO3
− anion and two uncoordinated water molecules; the NdIII cation, one coordinated water molecule, and the NO3
− anion each lie on a twofold axis of symmetry. The NdIII ion exhibits an NdN4O5 coordination environment comprising two O atoms of two monodentate 4-aminobenzenesulfonato ligands, four N atoms of the bidentate 1,10-phenanthroline ligands, and three water-O atoms. The coordination geometry is based on a tricapped triangular-prismatic arrangement. The components are consolidated into a three-dimensional network via O—H⋯O, O—H⋯N and N—H⋯O hydrogen-bonding interaction
4-[(5-Bromo-2-hydroxybenzylidene)amino]-3-propyl-1H-1,2,4-triazole-5(4H)-thione
The asymmetric unit of the title compound, C12H13BrN4OS, contains two independent molecules in which the dihedral angles between the triazole and benzene rings are 2.9 (3) and 7.5 (3)°. The thione group is of the form R
2C=S. An intramolecular O—H⋯N hydrogen bond occurs in each molecule. The crystal structure features weak N—H⋯S interactions and π–π stacking of the benzene rings [centroid–centroid distance = 3.667 (3) Å]
OsRAMOSA2 Shapes Panicle Architecture through Regulating Pedicel Length
The panicle architecture of rice is an important characteristic that influences reproductive success and yield. It is largely determined by the number and length of the primary and secondary branches. The number of panicle branches is defined by the inflorescence meristem state between determinacy and indeterminacy; for example, the maize ramosa2 (ra2) mutant has more branches in its tassel through loss of spikelet determinacy. Some genes and factors influencing the number of primary and secondary branches have been studied, but little is known about the molecular mechanism underlying pedicel development, which also influences panicle architecture. We report here that rice OsRAMOSA2 (OsRA2) gene modifies panicle architecture through regulating pedicel length. Ectopic expression of OsRA2 resulted in a shortened pedicel while inhibition of OsRA2 through RNA interference produced elongated pedicel. In addition, OsRA2 influenced seed morphology. The OsRA2 protein localized to the nucleus and showed transcriptional activation in yeast; in accordance with its function in pedicel development, OsRA2 mRNA was enriched in the anlagen of axillary meristems, such as primary and secondary branch meristems and the spikelet meristems of young panicles. This indicates a conserved role of OsRA2 for shaping the initial steps of inflorescence architecture. Genetic analysis revealed that OsRA2 may control panicle architecture using the same pathway as that of the axillary meristem gene LAX1 (LAX PANICLE1). Moreover, OsRA2 acted downstream of RCN2 in regulating pedicel and branch lengths, but upstream of RCN2 for control of the number of secondary branches, indicating that branch number and length development in the panicle were respectively regulated using parallel pathway. Functional conservation between OsRA2 and AtLOB, and the conservation and diversification of RA2 in maize and rice are also discussed
Multiphysics Structured Eddy Current and Thermography Defects Diagnostics System in Moving Mode
Eddy current testing (ET) and eddy current thermography (ECT) are both important non-destructive testing (NDT) methods that have been widely used in the field of conductive materials evaluation. Conventional ECT systems have often employed to test static specimens eventhough they are inefficient when the specimen is large. In addition, the requirement of high-power excitation sources tends to result in bulky detection systems. To mitigate these problems, a moving detection mode of multiphysics structured ET and ECT is proposed in which a novel L-shape ferrite magnetic yoke circumambulated with array coils is designed. The theoretical derivation model of the proposed method is developed which is shown to improve the detection efficiency without compromising the excitation current by ECT. The specimens can be speedily evaluated by scanning at a speed of 50-250 mm/s while reducing the power of the excitation current due to the supplement of ET. The unique design of the excitation-receiving structure has also enhanced the detectability of omnidirectional cracks. Moreover, it does not block the normal direction visual capture of the specimens. Both numerical simulations and experimental studies on different defects have been carried out and the obtained results have shown the reliability and detection efficiency of the proposed system
Wide Graph Neural Networks: Aggregation Provably Leads to Exponentially Trainability Loss
Graph convolutional networks (GCNs) and their variants have achieved great
success in dealing with graph-structured data. However, it is well known that
deep GCNs will suffer from over-smoothing problem, where node representations
tend to be indistinguishable as we stack up more layers. Although extensive
research has confirmed this prevailing understanding, few theoretical analyses
have been conducted to study the expressivity and trainability of deep GCNs. In
this work, we demonstrate these characterizations by studying the Gaussian
Process Kernel (GPK) and Graph Neural Tangent Kernel (GNTK) of an
infinitely-wide GCN, corresponding to the analysis on expressivity and
trainability, respectively. We first prove the expressivity of infinitely-wide
GCNs decaying at an exponential rate by applying the mean-field theory on GPK.
Besides, we formulate the asymptotic behaviors of GNTK in the large depth,
which enables us to reveal the dropping trainability of wide and deep GCNs at
an exponential rate. Additionally, we extend our theoretical framework to
analyze residual connection-resemble techniques. We found that these techniques
can mildly mitigate exponential decay, but they failed to overcome it
fundamentally. Finally, all theoretical results in this work are corroborated
experimentally on a variety of graph-structured datasets.Comment: 23 pages, 4 figure
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