2,052 research outputs found

    Chemical Modification of Ginsenoside on Cell Viability and Cytokine Secretion

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    Background: Rb1 is a ginsenoside steroid glycoside found exclusively in the plant Panax ginseng. In an earlier report, we showed that Rb1 increased cell proliferation and reduced VEGF (vascular endothelial growth factor) secretion by human retinal pigment epithelial (ARPE19) cells. Objective: In the present study, we hypothesized that chemical modification of Rb1 changes the level of VEGF secretion by ARPE19 cells. Method: Three derivatives of Rb1 were chemically synthesized by hydrogenation (Rb1-H2), acetylation (Rb1-Acyl), and epoxidation (Rb1-Epoxy). Structural modifications were confirmed by 1H Nuclear Magnetic Resonance (NMR) spectra and Mass Spectrometry (MS). To test the biological activity, chemically modified compounds were added to cell culture media and incubated for 72 hours at a concentration of 250 nM at 37°C. Conditioned media were collected and cells were harvested/ counted after treatment. Viable cell numbers were determined by the trypan blue dye exclusion method and VEGF levels by Enzyme-Linked Immunosorbent Assays (ELISA). Results: Consistent with the prior report, results of the present study show Rb1 increased cell proliferation and decreased VEGF secretion. Similar to Rb1\u27s effect on cell proliferation, treatment with Rb1-H2, Rb1-Acyl and Rb1-Epoxy resulted in an increase in cell numbers. In contrast to Rb1- induced decrease in VEGF secretion, treatment with Rb1-H2, Rb-Acyl and Rb1-Epoxy resulted in increased VEGF levels. Conclusion: Chemical modifications of the ginsenoside Rb1 significantly affect the biological activity of VEGF secretion by ARPE19 cells. Additional SAR (Structure Activity Relationship) experiments will be conducted to study the detailed mechanisms by which how specific modifications of Rb1 functional groups alter biological activities

    Anomalous transport in Charney-Hasegawa-Mima flows

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    Transport properties of particles evolving in a system governed by the Charney-Hasegawa-Mima equation are investigated. Transport is found to be anomalous with a non linear evolution of the second moments with time. The origin of this anomaly is traced back to the presence of chaotic jets within the flow. All characteristic transport exponents have a similar value around μ=1.75\mu=1.75, which is also the one found for simple point vortex flows in the literature, indicating some kind of universality. Moreover the law γ=μ+1\gamma=\mu+1 linking the trapping time exponent within jets to the transport exponent is confirmed and an accumulation towards zero of the spectrum of finite time Lyapunov exponent is observed. The localization of a jet is performed, and its structure is analyzed. It is clearly shown that despite a regular coarse grained picture of the jet, motion within the jet appears as chaotic but chaos is bounded on successive small scales.Comment: revised versio

    Adsorption of proteins to thin-films of PDMS and its effect on the adhesion of human endothelial cells

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    This paper describes a simple and inexpensive procedure to produce thin-films of poly(dimethylsiloxane). Such films were characterized by a variety of techniques (ellipsometry, nuclear magnetic resonance, atomic force microscopy, and goniometry) and used to investigate the adsorption kinetics of three model proteins (fibrinogen, collagen type-I, and bovine serum albumin) under different conditions. The information collected from the protein adsorption studies was then used to investigate the adhesion of human dermal microvascular endothelial cells. The results of these studies suggest that these films can be used to model the surface properties of microdevices fabricated with commercial PDMS. Moreover, the paper provides guidelines to efficiently attach cells in BioMEMS devices.Fil: Chumbimuni Torres, Karin Y.. The University of Texas at San Antonio; Estados UnidosFil: Coronado, Ramon E.. The University of Texas at San Antonio; Estados UnidosFil: Mfuh, Adelphe M.. The University of Texas at San Antonio; Estados UnidosFil: Castro Guerrero, Carlos. The University of Texas at San Antonio; Estados UnidosFil: Silva, María Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Negrete, George R.. The University of Texas at San Antonio; Estados UnidosFil: Bizios, Rena. The University of Texas at San Antonio; Estados UnidosFil: Garcia, Carlos D.. The University of Texas at San Antonio; Estados Unido

    4,10-Diall­yloxy-1,2,3,6b,7,8,9,12b-octa­hydro­perylene

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    In the title compound, C26H28O2, the central atoms are coplanar, with the –CH2—CH2– links of the cyclo­hexene groups lying to either side of the plane and with the diall­yloxy residues twisted out of this plane [C—C—O—C torsion angles = 16.6 (3) and −13.9 (3)°]. In the crystal structure, mol­ecules are connected into chains propagating in [100] via C—H⋯π inter­actions

    Measurement of quarkonium production cross sections in pp collisions at root s=13 TeV

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    Differential production cross sections of prompt J/psi and psi(2S) charmonium and Upsilon(nS) (n = 1, 2, 3) bottomonium states are measured in proton-proton collisions at root s = 13 TeV, with data collected by the CMS detector at the LHC, corresponding to an integrated luminosity of 2.3 fb(-1) for the J/psi and 2.7 fb(-1) for the other mesons. The five quarkonium states are reconstructed in the dimuon decay channel, for dimuon rapidity vertical bar y vertical bar <1.2. The double-differential cross sections for each state are measured as a function of y and transverse momentum, and compared to theoretical expectations. In addition, ratios are presented of cross sections for prompt psi(2S) to J/psi, Upsilon(2S) to Upsilon(1S), and Upsilon(3S) to Upsilon(1S) production. (C) 2018 The Author(s). Published by Elsevier B.V.Peer reviewe

    Search for new long-lived particles at root s=13 TeV

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    A search for long-lived particles was performed with data corresponding to an integrated luminosity of 2.6 fb(-1) collected at a center-of-mass energy of 13 TeV by the CMS experiment in 2015. The analysis exploits two customized topological trigger algorithms, and uses the multiplicity of displaced jets to search for the presence of a signal decay occurring at distances between 1 and 1000 mm. The results can be interpreted in a variety of different models. For pair-produced long-lived particles decaying to two b quarks and two leptons with equal decay rates between lepton flavors, cross sections larger than 2.5 fb are excluded for proper decay lengths between 70-100 mm for a long-lived particle mass of 1130 GeV at 95% confidence. For a specific model of pair-produced, long-lived top squarks with R-parity violating decays to a b quark and a lepton, masses below 550-1130 GeV are excluded at 95% confidence for equal branching fractions between lepton flavors, depending on the squark decay length. This mass bound is the most stringent to date for top squark proper decay lengths greater than 3 mm. (C) 2018 The Author(s). Published by Elsevier B.V.Peer reviewe

    Constraints on anomalous Higgs boson couplings using production and decay information in the four-lepton final state

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    © 2017 The Author A search is performed for anomalous interactions of the recently discovered Higgs boson using matrix element techniques with the information from its decay to four leptons and from associated Higgs boson production with two quark jets in either vector boson fusion or associated production with a vector boson. The data were recorded by the CMS experiment at the LHC at a center-of-mass energy of 13TeV and correspond to an integrated luminosity of 38.6fb −1 . They are combined with the data collected at center-of-mass energies of 7 and 8TeV, corresponding to integrated luminosities of 5.1 and 19.7fb −1 , respectively. All observations are consistent with the expectations for the standard model Higgs boson

    Cross section measurement of t-channel single top quark production in pp collisions at root s=13 TeV

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    Upsilon (nS) polarizations versus particle multiplicity in pp collisions at root s=7 TeV

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    Search for single production of vector-like quarks decaying into a b quark and a W boson in proton-proton collisions at root s=13 TeV

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