389 research outputs found

    Гемицеллюлозный субстрат - индуктор биосинтеза L-лизин-α-оксидазы триходермой

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    Studies on the biosynthesis of L-lysine-α-oxidase enzyme by Trichoderma sp. were carried out using various growing methods and media with various carbon sources. The enzyme was actively synthesized only on the wheat brans medium. The growth of Trichoderma strains on the gemycellulose substrate medium showed a different range of L-amino acid oxidase activety.With the Trichoderma culture getting older, the range of amino-oxidase activety widened, but for each strain it remained unique.Биосинтез фермента L-лизин-α-оксидаза грибом триходермой исследован при различных способах выращивания и на средах с различными источниками углерода. Фермент активно синтезировался только на среде с пшеничными отрубями. Штаммы триходермы при росте на среде с гемицеллюлозным субстратом проявляли разный спектр активностей оксидаз L-аминокислот. С возрастом культуры триходермы спектр аминооксидазных активностей расширялся, но для каждого штамма он оставался индивидуальным

    Биологическая и биохимическая стабильность метаболитов почвенного сапрофита Trichoderma harzianum Rifai

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    Metabolic stability of soil saprophyte Trichoderma harzianum Rifai was investigated under the conditions of long-term storage. It was showed that under the conditions of long-term storage the soil saprophyte Trichoderma harzianum Rifai preserves it's enzymatic and biological activity.Исследована стабильность метаболитов почвенного сапрофита Trichoderma harzianum Rifai в процессе длительного хранения. Показано, что в процессе длительного хранения культуры почвенный сапрофит Trichoderma harzianum Rifai сохраняет свою ферментативную и биологическую активность

    Культивирование сапрофитного гриба триходерма и биосинтез L-лизин-α-оксидазы

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    Studies on the growth of the fungus Trichoderma and biosynthesis of L-lysine-α-oxidase enzyme were carried out with surface and deep methods of cultivation. Factors which control the activity of Trichoderma's metabolite L-lysine-α-oxidase were determined: relationship between enzyme's biosynthesis and the fungus sporulation; number of inoculum, aeration; initial pH value of fermentation medium; number of sources of carbon and nitrogen, degree of their assimilation. The possibility of secondary use of substrate for production of enzyme in vitro was indicated.Исследован рост гриба рода триходерма и биосинтез фермента L-лизин-α-оксидазы в зависимости от поверхностного и глубинного способов культивирования. Установлены факторы, регулирующие активность метаболита триходермы L-лизин-α-оксидазы: зависимость биосинтеза фермента от спорообразования гриба, количества инокулята, аэрации, значения исходной кислотности ферментационной среды, количества источников углерода и азота, степени их усвояемости. Показана возможность вторичного использования субстрата для получения фермента в лабораторных условиях

    SRPES and STM data for the model bimetallic Pd In HOPG catalysts Effects of mild post synthesis oxidative treatments

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    Post synthesis treatment of bimetallic catalysts in different gas phases resulting in the adsorption induced segregation is among promising approaches to enhance their activity not compromising selectivity towards a number of low temperature reactions. Our recently published paper M.A. Panafidin, A.V. Bukhtiyarov, I.P. Prosvirin, I.A. Chetyrin, A.Yu. Klyushin, A. Knop Gericke, N.S. Smirnova, P.V. Markov, I.S. Mashkovsky, Y.V. Zubavichus, A.Yu. Stakheev, V.I. Bukhtiyarov, A mild post synthesis oxidative treatment of Pd In HOPG bimetallic catalysts as a tool of their surface structure fine tuning. Appl. Surf. Sci. reports on Pd In intermetallic formation regularities and their evolution after storage in air as well as during treatment in oxygen at submillibar pressures. The current paper gives an extended representation of experimental ex situ in situ synchrotron based photoelectron spectroscopy SRPES and scanning tunnelling microscopy STM data used to derive scientific conclusions in the paper quoted abov

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

    Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

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    Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02

    Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

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    We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters

    Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

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    This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio

    Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS

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    The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table, corrected author list, matches final version in Physical Review Letter

    Measurement of the inclusive isolated prompt photon cross-section in pp collisions at sqrt(s)= 7 TeV using 35 pb-1 of ATLAS data

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    A measurement of the differential cross-section for the inclusive production of isolated prompt photons in pp collisions at a center-of-mass energy sqrt(s) = 7 TeV is presented. The measurement covers the pseudorapidity ranges |eta|<1.37 and 1.52<=|eta|<2.37 in the transverse energy range 45<=E_T<400GeV. The results are based on an integrated luminosity of 35 pb-1, collected with the ATLAS detector at the LHC. The yields of the signal photons are measured using a data-driven technique, based on the observed distribution of the hadronic energy in a narrow cone around the photon candidate and the photon selection criteria. The results are compared with next-to-leading order perturbative QCD calculations and found to be in good agreement over four orders of magnitude in cross-section.Comment: 7 pages plus author list (18 pages total), 2 figures, 4 tables, final version published in Physics Letters
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