1,385 research outputs found

    3-(4-Fluoro­phen­yl)-1-(4-methoxy­phen­yl)prop-2-en-1-one

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    The title compound, C16H13FO2, was prepared from 4-methoxy­hypnone and 4-fluoro­benzophenone by Claisen–Schmidt condensation. All the bond lengths and bond angles are in normal ranges. The dihedral angle formed by the two benzene rings is 33.49 (2)°. The crystal packing is stabilized by inter­molecular C—H⋯O hydrogen-bonding inter­actions

    Crystal engineered acid–base complexes with 2D and 3D hydrogen bonding systems using p-hydroxybenzoic acid as the building block

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    p-Hydroxybenzoic acid (p-HOBA) was selected as the building block for self-assembly with five bases, i.e., diethylamine, tert-butylamine, cyclohexylamine, imidazole and piperazine, and generation of the corresponding acid–base complexes 1–5. Crystal structure analyses suggest that proton-transfer from the carboxyl hydrogen to the nitrogen atom of the bases can be observed in 1–4, while only in 5 does a solvent water molecule co-exist with p--HOBA and piperazine. With the presence of O–H···O hydrogen bonds in 1–4, the deprotonated p-hydroxybenzoate anions (p-HOBAA–) are simply connected each other in a head-to-tail motif to form one-dimensional (1D) arrays, which are further extended to distinct two-dimensional (2D) (for 1 and 4) and three-dimensional (3D) (for 2 and 3) networks via N–H···O interactions. While in 5, neutral acid and base are combined pair-wise by O–H···N and N–H···O bonds to form a 1D tape and then the 1D tapes are sequentially combined by water molecules to create a 3D network. Some interlayer or intralayer C–H···O, C–H···p and p×××p interactions help to stabilize the supramolecular buildings. Melting point determination analyses indicate that the five acid–base complexes are not the ordinary superposition of the reactants and they are more stable than the original reactants

    Passivity Analysis of Complex Delayed Dynamical Networks with Output Coupling

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    A new complex dynamical network model with output coupling is proposed. This paper is concerned with input passivity and output passivity of the proposed network model. By constructing new Lyapunov functionals, some sufficient conditions ensuring the input passivity and output passivity are obtained. Finally, two numerical examples are provided to demonstrate the effectiveness of the proposed results

    Detecting and removing visual distractors for video aesthetic enhancement

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    Personal videos often contain visual distractors, which are objects that are accidentally captured that can distract viewers from focusing on the main subjects. We propose a method to automatically detect and localize these distractors through learning from a manually labeled dataset. To achieve spatially and temporally coherent detection, we propose extracting features at the Temporal-Superpixel (TSP) level using a traditional SVM-based learning framework. We also experiment with end-to-end learning using Convolutional Neural Networks (CNNs), which achieves slightly higher performance than other methods. The classification result is further refined in a post-processing step based on graph-cut optimization. Experimental results show that our method achieves an accuracy of 81% and a recall of 86%. We demonstrate several ways of removing the detected distractors to improve the video quality, including video hole filling; video frame replacement; and camera path re-planning. The user study results show that our method can significantly improve the aesthetic quality of videos

    An efficient ICT-based ratio/colorimetric tripodal azobenzene probe for the recognition/discrimination of F−, AcO− and H2PO4− anions

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    The tripodal probe L was readily prepared via introducing rhodamine and azobenzene groups in a two-step procedure. Studies of the recognition properties indicated that probe L exhibited high sensitivity and selectivity towards F−, AcO− and H2PO4− through a ratiometric colorimetric response with low detection limits of the order of 10−7 M. The complexation behaviour was fully investigated by spectral titration, 1H NMR spectroscopic titration and mass spectrometry. Probe L not only recognizes F−, AcO− and H2PO4−, but can also distinguish between these three anions via the different ratiometric behaviour in their UV–vis spectra (387/505 nm for L-H2PO4−, 387/530 nm for L-AcO− and 387/575 nm for L-F− complex) or via different colour changes (light coral for L-H2PO4−, light pink for L-AcO− and violet for the L-F− complex). Additionally, given the presence of NH and OH groups in probe L, which can be protonated and deprotonated, probe L further exhibited an excellent pH response over a wide pH range (pH 3 to pH 12)

    Selection and evaluation of phosphate-solubilizing bacteria from grapevine rhizospheres for use as biofertilizers

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    Phosphate-solubilizing bacteria (PSB) have the ability to solubilize insoluble phosphorus (P) and release soluble P. Extensive research has been performed with respect to PSB isolation from the rhizospheres of various plants, but little is known about the prevalence of PSB in the grapevine rhizosphere. In this study, we aimed to isolate and identify PSB from the grapevine rhizosphere in five vineyards of Northwest China, to characterize their plant-growth-promoting (PGP) traits, evaluate the effect of stress on their phosphate-solubilizing activity (PSA), and test their ability to stimulate the growth of Vitis vinifera L. cv. Cabernet Sauvignon. From the vineyard soils, 66 PSB isolates were screened, and 10 strains with high PSA were identified by 16S rRNA sequencing. Sequence analysis revealed that these 10 strains belonged to 4 genera and 5 species: Bacillus aryabhattai, B. megaterium, Klebsiella variicola, Stenotrophomonas rhizophila, and Enterobacter aerogenes. The selected PSB strains JY17 (B. aryabhattai) and JY22 (B. aryabhattai) were positive for multiple PGP traits, including nitrogen fixation and production of indole acetic acid (IAA), siderophores, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, chitinase, and protease. JY17 and JY22 showed strong PSA under stress conditions of high pH, high salt, and high temperature. Therefore, these two isolates can be used as biofertilizers in saline-alkaline soils. The inoculation with PSB significantly facilitated the growth of V. vinifera cv. Cabernet Sauvignon under greenhouse conditions. Use of these PSB as biofertilizers will increase the available P content in soils, minimize P-fertilizer application, reduce environmental pollution, and promote sustainable agriculture

    Novel Polysaccharide H-1-2 from Pseudostellaria Heterophylla Alleviates Type 2 Diabetes Mellitus

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    Background/Aims: To investigate the potential therapeutic effect of novel polysaccharide H-1-2 from pseudostellaria heterophylla against type 2 Diabetes Mellitus (T2DM) and elucidate the underling molecular mechanisms. Methods: Relative expression of HIF1α and Sirt1 in T2DM patients was determined via real-time PCR. The direct binding of HIF1α on Sirt1 promoter was validated by ChIP assay. The inhibitory regulation of Sirt1 by HIF1α was analyzed using luciferase reporter assay. The endogenous protein of HIF1α and Sirt1 in response to H-1-2 treatment was quantified by western blotting. The blood glucose, secreted insulin and serous lipid profiles were measured with ELISA kits. Results: We consolidated that HIF1α and Sirt1 was dysregulated in T2DM patients and subjected to H-1-2 modulation. H-1-2 significantly inhibited hypoxia and up-regulated Sirt1 expression in EndoC-βH1 cells. Accordingly, H-1-2 enhanced glucose-stimulation insulin secretion and improved blood glucose and lipid profiles in T2DM cells, and elevated the glucose and insulin tolerance simultaneously. Furthermore, we demonstrated that H-1-2 alleviated T2DM via inhibition of hypoxia and up-regulation of Sirt1 in isolated pancreatic β-cells from T2DM rats. Conclusion: Our data unambiguously demonstrated H-1-2 administration alleviated T2DM by enhancing Sirt1 expression through inhibition of hypoxia
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