121 research outputs found

    Corticosterone Potentiation of Cocaine-Induced Reinstatement of Conditioned Place Preference in Mice is Mediated by Blockade of the Organic Cation Transporter 3

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    The mechanisms by which stressful life events increase the risk of relapse in recovering cocaine addicts are not well understood. We previously reported that stress, via elevated corticosterone, potentiates cocaine-primed reinstatement of cocaine seeking following self-administration in rats and that this potentiation appears to involve corticosterone-induced blockade of dopamine clearance via the organic cation transporter 3 (OCT3). In the present study, we use a conditioned place preference/reinstatement paradigm in mice to directly test the hypothesis that corticosterone potentiates cocaine-primed reinstatement by blockade of OCT3. Consistent with our findings following self-administration in rats, pretreatment of male C57/BL6 mice with corticosterone (using a dose that reproduced stress-level plasma concentrations) potentiated cocaine-primed reinstatement of extinguished cocaine-induced conditioned place preference. Corticosterone failed to re-establish extinguished preference alone but produced a leftward shift in the dose–response curve for cocaine-primed reinstatement. A similar potentiating effect was observed upon pretreatment of mice with the non-glucocorticoid OCT3 blocker, normetanephrine. To determine the role of OCT3 blockade in these effects, we examined the abilities of corticosterone and normetanephrine to potentiate cocaine-primed reinstatement in OCT3-deficient and wild-type mice. Conditioned place preference, extinction and reinstatement of extinguished preference in response to low-dose cocaine administration did not differ between genotypes. However, corticosterone and normetanephrine failed to potentiate cocaine-primed reinstatement in OCT3-deficient mice. Together, these data provide the first direct evidence that the interaction of corticosterone with OCT3 mediates corticosterone effects on drug-seeking behavior and establish OCT3 function as an important determinant of susceptibility to cocaine use

    Highly Parallel Translation of DNA Sequences into Small Molecules

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    A large body of in vitro evolution work establishes the utility of biopolymer libraries comprising 1010 to 1015 distinct molecules for the discovery of nanomolar-affinity ligands to proteins.[1], [2], [3], [4], [5] Small-molecule libraries of comparable complexity will likely provide nanomolar-affinity small-molecule ligands.[6], [7] Unlike biopolymers, small molecules can offer the advantages of cell permeability, low immunogenicity, metabolic stability, rapid diffusion and inexpensive mass production. It is thought that such desirable in vivo behavior is correlated with the physical properties of small molecules, specifically a limited number of hydrogen bond donors and acceptors, a defined range of hydrophobicity, and most importantly, molecular weights less than 500 Daltons.[8] Creating a collection of 1010 to 1015 small molecules that meet these criteria requires the use of hundreds to thousands of diversity elements per step in a combinatorial synthesis of three to five steps. With this goal in mind, we have reported a set of mesofluidic devices that enable DNA-programmed combinatorial chemistry in a highly parallel 384-well plate format. Here, we demonstrate that these devices can translate DNA genes encoding 384 diversity elements per coding position into corresponding small-molecule gene products. This robust and efficient procedure yields small molecule-DNA conjugates suitable for in vitro evolution experiments

    Charged-particle distributions at low transverse momentum in √s=13 13 TeV pp interactions measured with the ATLAS detector at the LHC

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    Measurements of distributions of charged particles produced in proton–proton collisions with a centre-of-mass energy of 13 TeV are presented. The data were recorded by the ATLAS detector at the LHC and correspond to an integrated luminosity of 151 μb −1 μb−1 . The particles are required to have a transverse momentum greater than 100 MeV and an absolute pseudorapidity less than 2.5. The charged-particle multiplicity, its dependence on transverse momentum and pseudorapidity and the dependence of the mean transverse momentum on multiplicity are measured in events containing at least two charged particles satisfying the above kinematic criteria. The results are corrected for detector effects and compared to the predictions from several Monte Carlo event generators

    Measurement of W+W− production in association with one jet in proton–proton collisions at sqrt(s) = 8TeV with the ATLAS detector

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    The production of W boson pairs in association with one jet in pp collisions at View the MathML sources=8 TeV is studied using data corresponding to an integrated luminosity of 20.3 fb−1 collected by the ATLAS detector during 2012 at the CERN Large Hadron Collider. The cross section is measured in a fiducial phase-space region defined by the presence of exactly one electron and one muon, missing transverse momentum and exactly one jet with a transverse momentum above 25 GeV and a pseudorapidity of |η|<4.5|η|<4.5. The leptons are required to have opposite electric charge and to pass transverse momentum and pseudorapidity requirements. The fiducial cross section is found to be View the MathML sourceσWWfid,1-jet=136±6(stat)±14(syst)±3(lumi) fb. In combination with a previous measurement restricted to leptonic final states with no associated jets, the fiducial cross section of WW production with zero or one jet is measured to be View the MathML sourceσWWfid,≤1-jet=511±9(stat)±26(syst)±10(lumi) fb. The ratio of fiducial cross sections in final states with one and zero jets is determined to be 0.36±0.050.36±0.05. Finally, a total cross section extrapolated from the fiducial measurement of WW production with zero or one associated jet is reported. The measurements are compared to theoretical predictions and found in good agreement

    Search for pair production of Higgs bosons in the bb¯bb¯ final state using proton-proton collisions at √s=13  TeV with the ATLAS detector

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    A search for Higgs-boson pair production in the bb ¯ bb ¯ final state is carried out with 3.2  fb −1 of proton-proton collision data collected at s √ =13  TeV with the ATLAS detector. The data are consistent with the estimated background and are used to set upper limits on the production cross section of Higgs-boson pairs times branching ratio to bb ¯ bb ¯ for both nonresonant and resonant production. In the case of resonant production of Kaluza-Klein gravitons within the Randall-Sundrum model, upper limits in the 24 to 91 fb range are obtained for masses between 600 and 3000 GeV, at the 95% confidence level. The production cross section times branching ratio for nonresonant Higgs-boson pairs is also constrained to be less than 1.22 pb, at the 95% confidence level

    A search for pair-produced resonances in four-jet final states at root s=13 TeV with the ATLAS detector

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    A search for massive coloured resonances which are pair-produced and decay into two jets is presented. The analysis uses 36.7 fb−1 − 1 of √ s = 13 TeV pp collision data recorded by the ATLAS experiment at the LHC in 2015 and 2016. No significant deviation from the background prediction is observed. Results are interpreted in a SUSY simplified model where the lightest supersymmetric particle is the top squark, ̃ t ~ , which decays promptly into two quarks through R-parity-violating couplings. Top squarks with masses in the range 100 GeV<̃<410 100 GeV < m t ~ < 410 GeV GeV are excluded at 95% confidence level. If the decay is into a b-quark and a light quark, a dedicated selection requiring two b-tags is used to exclude masses in the ranges 100 GeV<̃<470 100 GeV < m t ~ < 470 GeV GeV and 480 GeV<̃<610 480 GeV < m t ~ < 610 GeV GeV . Additional limits are set on the pair-production of massive colour-octet resonances

    Search for excited electrons singly produced in proton–proton collisions at \sqrt{s} = 13 TeV with the ALAS experiment at the LHC

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    A search for excited electrons produced in pp collisions at s√ = 13 TeV via a contact interaction qq¯→ee∗ is presented. The search uses 36.1 fb −1 of data collected in 2015 and 2016 by the ATLAS experiment at the Large Hadron Collider. Decays of the excited electron into an electron and a pair of quarks ( eqq¯ ) are targeted in final states with two electrons and two hadronic jets, and decays via a gauge interaction into a neutrino and a W boson ( νW ) are probed in final states with an electron, missing transverse momentum, and a large-radius jet consistent with a hadronically decaying W boson. No significant excess is observed over the expected backgrounds. Upper limits are calculated for the pp→ee∗→eeqq¯ and pp→ee∗→eνW production cross sections as a function of the excited electron mass me∗ at 95% confidence level. The limits are translated into lower bounds on the compositeness scale parameter Λ of the model as a function of me∗ . For me∗<0.5 TeV , the lower bound for Λ is 11 TeV . In the special case of me∗=Λ , the values of me∗<4.8 TeV are excluded. The presented limits on Λ are more stringent than those obtained in previous searches

    Determination of the strong coupling constant αs from transverse energy–energy correlations in multijet events at s√=8 TeV using the ATLAS detector

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    Measurements of transverse energy–energy correlations and their associated asymmetries in multi-jet events using the ATLAS detector at the LHC are presented. The data used correspond to s√=8 TeV proton–proton collisions with an integrated luminosity of 20.2 fb−1 . The results are presented in bins of the scalar sum of the transverse momenta of the two leading jets, unfolded to the particle level and compared to the predictions from Monte Carlo simulations. A comparison with next-to-leading-order perturbative QCD is also performed, showing excellent agreement within the uncertainties. From this comparison, the value of the strong coupling constant is extracted for different energy regimes, thus testing the running of αs(μ) predicted in QCD up to scales over 1 TeV . A global fit to the transverse energy–energy correlation distributions yields αs(mZ)=0.1162±0.0011(exp.) +0.0084−0.0070(theo.) , while a global fit to the asymmetry distributions yields a value of αs(mZ)=0.1196±0.0013(exp.) +0.0075−0.0045(theo.)

    Measurements of electroweak Wjj production and constraints on anomalous gauge couplings with the ATLAS detector

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    Measurements of the electroweak production of a W boson in association with two jets at high dijet invariant mass are performed using root s = 7 and 8 TeV proton-proton collision data produced by the Large Hadron Collider, corresponding respectively to 4.7 and 20.2 fb(-1) of integrated luminosity collected by the ATLAS detector. The measurements are sensitive to the production of a W boson via a triple-gauge-boson vertex and include both the fiducial and differential cross sections of the electroweak process

    Search for squarks and gluinos in final states with jets and missing transverse momentum at root s=13 TeV with the ATLAS detector

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