We report a measurement of the fraction of b quarks produced diffractively in p collisions at sqrts = 1.8 TeV. Diffraction is identified by the absence of particles in a forward pseudorapidity ...region. From events with an electron of transverse momentum 9.5<p(e)(T)<20 GeV/ c within the pseudorapidity region |eta|<1.1, the ratio of diffractive to total b-quark production rates is found to be R( b) = 0.62+/-0.19(stat)+/-0.16(syst)%. This result is comparable in magnitude to corresponding ratios for W and dijet production but significantly lower than expectations based on factorization.
The hypocholesterolemic activities of pamaqueside and tiqueside, two structurally similar saponins, were evaluated in cholesterol-fed rabbits. The pharmacological profiles of the saponins were ...virtually identical: both dose-dependently decreased the intestinal absorption of labeled cholesterol 25-75%, increased fecal neutral sterol excretion up to 2.5-fold, and decreased hepatic cholesterol content 10-55%. High doses of pamaqueside (>5 mg/kg) or tiqueside (>125 mg/kg) completely prevented hypercholesterolemia. Decreases in plasma and hepatic cholesterol levels were strongly correlated with increased neutral sterol excretion. Ratios of neutral sterol excreted to pamaqueside administered were greater than 1:1 at all doses, in opposition to the formation of a stoichiometric complex previously suggested for tiqueside and other saponins. Ratios in tiqueside-treated rabbits were less than unity, a reflection of its lower potency. Pamaqueside-treated rabbits exhibited a more rapid decline in plasma cholesterol concentrations than control animals fed a cholesterol-free diet, indicating that the compound also inhibited the absorption of biliary cholesterol. Intravenous administration of pamaqueside had no effect on plasma cholesterol levels despite plasma levels twice those observed in rabbits given pamaqueside orally. These data indicate that pamaqueside and tiqueside induce hypocholesterolemia by blocking lumenal cholesterol absorption via a mechanism that apparently differs from the stoichiometric complexation of cholesterol hypothesized for other saponins.
Initial performance of the CUORE detector Cushman, J. S.; Alduino, C.; Alfonso, K. ...
Journal of physics. Conference series,
01/2020, Letnik:
1342, Številka:
1
Journal Article
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CUORE, the Cryogenic Underground Observatory for Rare Events, is an experiment searching for the neutrinoless double-beta decay of 130Te. The first CUORE dataset was acquired in May and June 2017 and ...consisted of 10.6 kg-yr of TeO2 exposure, with several days of calibration data before and after the physics dataset. We discuss here the initial performance of the CUORE detector and cryostat in this first dataset.
We present a search for the pair production of a narrow nonstandard-model strongly interacting particle that decays to a pair of quarks or gluons, leading to a final state with four hadronic jets. We ...consider both nonresonant production via an intermediate gluon as well as resonant production via a distinct nonstandard-model intermediate strongly interacting particle. We use data collected by the CDF experiment in proton-antiproton collisions at √s=1.96 TeV corresponding to an integrated luminosity of 6.6 fb(-1). We find the data to be consistent with nonresonant production. We report limits on σ(ppover ¯→jjjj) as a function of the masses of the hypothetical intermediate particles. Upper limits on the production cross sections for nonstandard-model particles in several resonant and nonresonant processes are also derived.
We report on a search for double beta decay of Formula omitted to the first Formula omitted excited state of Formula omitted using a Formula omitted exposure of Formula omitted collected with the ...CUORE-0 experiment. In this work we exploit different topologies of coincident events to search for both the neutrinoless and two-neutrino double beta decay modes. We find no evidence for either mode and place lower bounds on the half-lives: Formula omitted and Formula omitted ( Formula omitted). Combining our results with those obtained by the CUORICINO experiment, we achieve the most stringent constraints available for these processes: Formula omitted and Formula omitted ( Formula omitted).
We present the first observation of exclusive e(+)e(-) production in hadron-hadron collisions, using ppover collision data at (square root) s = 1.96 TeV taken by the run II Collider Detector at ...Fermilab, and corresponding to an integrated luminosity of 532 pb(-1). We require the absence of any particle signatures in the detector except for an electron and a positron candidate, each with transverse energy E(T) > 5 GeV and pseudorapidity |eta| < 2. With these criteria, 16 events are observed compared to a background expectation of 1.9+/-0.3 events. These events are consistent in cross section and properties with the QED process ppover --> p + e(+)e(-) + pover through two-photon exchange. The measured cross section is 1.6(-0.3)(+0.5)(stat) +/- 0.3(syst) pb. This agrees with the theoretical prediction of 1.71+/-0.01 pb.
We have explored the use of steroidal glycosides as cholesterol absorption inhibitors which act through an unknown mechanism. The lead for this program was tigogenin cellobioside (1, tiqueside) which ...is a weak inhibitor (ED50 = 60 mg/kg) as measured in an acute hamster cholesterol absorption assay. Modification of the steroid portion of the molecule led to the discovery of 11-ketotigogenin cellobioside (5, pamaqueside) which has an ED50 of 2 mg/kg. Replacement of the cellobiose with other sugars failed to provide more potent analogs. However, large improvements in potency were realized through modification of the hydroxyl groups on the cellobiose. This strategy ultimately led to the 4‘‘,6‘‘-bis(2-fluorophenyl)carbamoyl-β-d-cellobiosyl derivative of 11-ketotigogenin (51) with an ED50 of 0.025 mg/kg in the hamster assay, as well as the corresponding hecogenin analog 64 (ED50 = 0.07 mg/kg).
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