833 research outputs found

    1-Aryl-3-[4-(thieno[3,2-d]pyrimidin-4-yloxy)phenyl]ureas as potential inhibitors of VEGFR-2: synthesis and molecular modelling studies

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    Angiogenesis is a requirement for tumor growth and metastasis and occurs through several signalling pathways. One key pathway that initiates proliferation and migration of endothelial cells is signalling through the vascular endothelial growth factor receptor-2 (VEGFR-2).1 Therefore, small molecules that block this signalling pathway through inhibition of the VEGFR tyrosine kinase activity could potentially inhibit angiogenesis and tumour growth. Recently works describing thienopyrimidines2 and thienopyridine ureas3 as inhibitors of VEGFR-2 have appeared in the literature. Here we present the synthesis of new 1,3-diarylureas 2 starting by regioselective nucleophilic substitution of the 4-chlorothieno[3,2-d]pyrimidine with 4-aminophenol to obtain 4-(thieno[3,2-d]pyridin-4-yloxy)aniline 1 which reacts with different arylisocyanate

    1-aryl-3-(4-(7-methylthieno[3,2-d]pyrimidin-4-yloxy)phenyl)ureas: synthesis and molecular modelling studies using VEGFR-2

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    The development of anticancer drugs inhibiting angiogenesis has been an area of extensive research in the past decade. Angiogenesis is a requirement for tumor growth and metastasis and occurs through several signalling pathways. One key pathway that initiates proliferation and migration of endothelial cells is signalling through the vascular endothelial growth factor receptor-2 (VEGFR-2).1 Therefore, small molecules that block this signalling pathway through inhibition of VEGFR-2 tyrosine kinase activity could potentially inhibit angiogenesis and tumor growth. Recently works describing thienopyrimidine2 and thienopyrimidine 1,3-diarylureas3 as VEGFR-2 inhibitors have emerged in the literature. Here we present the synthesis of new 1-aryl-3-(4-(7-methylthieno[3,2-d]pyrimidin-4-yloxy)phenyl)ureas 2 in high yields by reaction of 4-[(7-methylthieno[3,2-d]pyridin-4-yl)oxy]aniline 1 with arylisocyanates. The former was prepared by regioselective nucleophilic substitution of 4-chloro-7-methylthieno[3,2-d]pyrimidine with 4-aminopheno

    Thieno[3,2-b]pyridine arylethers: synthesis and growth inhibitory activity on human tumor cell lines

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    Thienopyridine skeleton has been reported as havi ng inte resting biological activity, namely antitumorlll and antiangiogenic121 activities. Herein, we describe the synth esis of thienopyridine arylethers la-f in moderate to good yields by a copper-cata lyzed C- 0 coupling, using N,N-dimethylglycine as a ligand, of the 7-bromothieno[3,2-b]pyridine, also prepared with substituted phenols (see scheme)

    Flocculation onset in Saccharomyces cerevisiae: effect of ethanol, heat and osmotic stress

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    Aims: To examine the effect of different stress conditions on the onset of flocculation in an ale-brewing strain, Saccharomyces cerevisiae NCYC 1195. Methods and Results: Flocculation was evaluated using the method of Soares, E.V. and Vroman, A. [Journal of Applied Microbiology (2003) 95, 325]; plasma membrane integrity was accessed using propidium iodide and the staining of the yeast cell wall was performed using calcofluor white M2R. Cells in exponential phase of growth were subjected to different stress conditions. The addition of 1%, 3% and 5% (v/v) ethanol, 1% and 3% (v/v) isopropanol or a brief heat shock (52ºC, 5 min), did not induce an early flocculation phenotype when compared with control cells. The addition of 10% (v/v) ethanol, a continuous mild heat-stress (37ºC) or an osmotic stress (0.5 or 1 mol l-1 of NaCl) did not induce a flocculent phenotype. Conclusions: Flocculation seems not to be induced as a response to different chemical (ethanol and isopropanol) and physical (heat and osmotic) stress conditions. Conversely, osmotic and ethanol [10% (v/v)] stress, as well as a continuous mild heat shock (37ºC), have a negative impact on the phenotype expression of flocculation. Significance and Impact of the Study: The findings reported here contribute to the elucidation of the control of yeast flocculation. This information might be useful to the brewing industry, as the time when the onset of flocculation occurs can determine the fermentation performance and the beer quality, as well as in other biotechnological industries where flocculation can be used as a cell separation process.ERASMUS; ISEP (Portugal)

    Synthesis, molecular Docking and biological evaluation of new 1-Aryl-3-[3-(thieno[3,2-b]pyridin-7-ylthio)phenylureas as Potent Type II VEGFR-2 Tyrosine Kinase inhibitors

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    The vascular endothelial growth factor receptor 2 (VEGFR-2) is a tyrosine kinase receptor, expressed primarily in endothelial cells, and is activated by the specific binding of VEGF to the VEGFR-2 extracellular regulatory domain. Once activated, VEGFR-2 undergoes autophosphorylation, triggering signaling pathways leading to endothelial cell proliferation and subsequent angiogenesisY1 Small molecules may act as inhibitors by competing for the ATP-binding s'1te of the VEGFR-2 intracellular tyrosine kinase domain, thereby preventing the intracellular signa ling that leads to angiogenesis. [ZJ Here, we present the synthesis of new 1-aryl-3-[3-(thieno[3,2-b]pyridin-7-ylthio)phenyl]ureas la-c, as potent type 11 VEGFR-2 inhibitors based on molecular docking (Figure A) and biological evaluation including enzymatic assays using the VEGFR-2 tyrosine kinase domain (ICso=l0-28 nM) and studies in human umbilical vein endothelial cells (HUVECs). The latter included cell viability (MTS), proliferation (BrdU) and Western blot for total and phosphorylated VEGFR-2 (Figure B). The predicted docked poses were analyzed in detail and a plausible explanation for compounds 1 potency was obtained base9 on the simultaneous presence of a S-linker and the arylurea moiety in the meta position as a new substitution pattern for the type 11 VEGFR-2 inhibitors. These chemical features place the thieno[3,2-b]pyridine and the terminal aryl ring in close superimposition to a pyrrolo[3,2-d]pyrimidine derivative. The presence of hydrofobic substituents (F and Me) in the terminal aryl ring is also important. For these compounds a significant inhibition in HUVECs proliferation upon VEGF stimulation was observed at low concentrations (0.5-1.0 IJ.M) without affecting cell viability. Westernblot analysis demonstrated that compounds 1 significantly the inhibited VEGFR-2 phosphorylation at 1.0 jlM, thus confirming their anti-angiogenic potential

    Measurement of D*+/- meson production in jets from pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    This paper reports a measurement of D*+/- meson production in jets from proton-proton collisions at a center-of-mass energy of sqrt(s) = 7 TeV at the CERN Large Hadron Collider. The measurement is based on a data sample recorded with the ATLAS detector with an integrated luminosity of 0.30 pb^-1 for jets with transverse momentum between 25 and 70 GeV in the pseudorapidity range |eta| < 2.5. D*+/- mesons found in jets are fully reconstructed in the decay chain: D*+ -> D0pi+, D0 -> K-pi+, and its charge conjugate. The production rate is found to be N(D*+/-)/N(jet) = 0.025 +/- 0.001(stat.) +/- 0.004(syst.) for D*+/- mesons that carry a fraction z of the jet momentum in the range 0.3 < z < 1. Monte Carlo predictions fail to describe the data at small values of z, and this is most marked at low jet transverse momentum.Comment: 10 pages plus author list (22 pages total), 5 figures, 1 table, matches published version in Physical Review

    Highlights of the São Paulo ISEV workshop on extracellular vesicles in cross-kingdom communication

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    In the past years, extracellular vesicles (EVs) have become an important field of research since EVs have been found to play a central role in biological processes. In pathogens, EVs are involved in several events during the host–pathogen interaction, including invasion, immunomodulation, and pathology as well as parasite–parasite communication. In this report, we summarised the role of EVs in infections caused by viruses, bacteria, fungi, protozoa, and helminths based on the talks and discussions carried out during the International Society for Extracellular Vesicles (ISEV) workshop held in São Paulo (November, 2016), Brazil, entitled Cross-organism Communication by Extracellular Vesicles: Hosts, Microbes and Parasites. © 2017 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.11Ysciescopu

    Search for supersymmetry in final states with jets, missing transverse momentum and one isolated lepton in sqrt{s} = 7 TeV pp collisions using 1 fb-1 of ATLAS data

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    We present an update of a search for supersymmetry in final states containing jets, missing transverse momentum, and one isolated electron or muon, using 1.04 fb^-1 of proton-proton collision data at sqrt{s} = 7 TeV recorded by the ATLAS experiment at the LHC in the first half of 2011. The analysis is carried out in four distinct signal regions with either three or four jets and variations on the (missing) transverse momentum cuts, resulting in optimized limits for various supersymmetry models. No excess above the standard model background expectation is observed. Limits are set on the visible cross-section of new physics within the kinematic requirements of the search. The results are interpreted as limits on the parameters of the minimal supergravity framework, limits on cross-sections of simplified models with specific squark and gluino decay modes, and limits on parameters of a model with bilinear R-parity violation.Comment: 18 pages plus author list (30 pages total), 9 figures, 4 tables, final version to appear in Physical Review

    Reducing heterotic M-theory to five dimensional supergravity on a manifold with boundary

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    This paper constructs the reduction of heterotic MM-theory in eleven dimensions to a supergravity model on a manifold with boundary in five dimensions using a Calabi-Yau three-fold. New results are presented for the boundary terms in the action and for the boundary conditions on the bulk fields. Some general features of dualisation on a manifold with boundary are used to explain the origin of some topological terms in the action. The effect of gaugino condensation on the fermion boundary conditions leads to a `twist' in the chirality of the gravitino which can provide an uplifting mechanism in the vacuum energy to cancel the cosmological constant after moduli stabilisation.Comment: 16 pages, RevTe

    Measurement of tau polarization in W->taunu decays with the ATLAS detector in pp collisions at sqrt(s) = 7 TeV

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    In this paper, a measurement of tau polarization in W->taunu decays is presented. It is measured from the energies of the decay products in hadronic tau decays with a single final state charged particle. The data, corresponding to an integrated luminosity of 24 pb^-1, were collected by the ATLAS experiment at the Large Hadron Collider in 2010. The measured value of the tau polarization is Ptau = -1.06 +/- 0.04 (stat) + 0.05 (syst) - 0.07 (syst), in agreement with the Standard Model prediction, and is consistent with a physically allowed 95% CL interval [-1,-0.91]. Measurements of tau polarization have not previously been made at hadron colliders.Comment: 10 pages plus author list (25 pages total), 4 figures, 4 tables, revised author list, matches published EPJC versio
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