655 research outputs found

    The first crystallographically-characterised Cu(II) xanthate

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    AbstractThe copper(II) xanthate Cu(S2COEt)2·TMEDA (1) (TMEDA=N,N-tetramethylethylenediamine) has been synthesised and is the first structurally-characterised xanthate of copper in the +2 oxidation state. 1 has an octahedral cis, cis, cis-ligand arrangement about the metal, in which xanthate chelation is markedly asymmetric. Both bulk thermal decomposition and film growth by aerosol-assisted chemical vapour deposition (AACVD) using 1 as precursor lead to the formation of Cu2S

    Perfectionism and attitudes towards doping in athletes: The mediating role of achievement goal orientations

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    Perfectionism predicts attitudes towards doping in athletes. It is currently unclear, however, why this is the case. To help shed light on this particular issue, in the present study we provided a first examination of whether achievement goal orientations explain (mediate) the relationship between perfectionism and attitudes towards doping. A sample of 173 athletes (mean age 24.4 years) completed measures of perfectionistic strivings, perfectionistic concerns, ego-orientation, task-orientation, and attitudes towards doping. Based on bias-corrected bootstrapping of indirect effects, ego-orientation mediated the positive relationships between perfectionistic strivings and attitudes towards doping and perfectionistic concerns and attitudes towards doping. Task-orientation mediated the negative relationship between perfectionistic strivings and attitudes towards doping. In this regard, athletes high in either dimension of perfectionism have more favourable attitudes because of a tendency to define success as outperforming others. However, those athletes high in perfectionistic strivings may simultaneously hold less favourable attitudes because they also have a tendency to define success as improving their own performance

    Chronologic distribution of stroke after minimally invasive versus conventional coronary artery bypass

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    AbstractObjectivesWe sought to investigate whether the chronologic distribution of the onset of stroke occurring after coronary artery bypass graft surgery (CABG) without cardiopulmonary bypass (off-pump CABG) is different from the conventional on-pump approach (CABG with cardiopulmonary bypass).BackgroundOff-pump CABG has been associated with a lower stroke rate, compared with conventional on-pump CABG. However, it is unknown whether the chronologic distribution of the onset of stroke is different between the two approaches.MethodsWe evaluated the chronologic distribution of postoperative stroke in patients undergoing CABG from June 1996 to August 2001 (n = 10,573). Preoperative risk factors for stroke were identified using the Northern New England preoperative estimate of stroke risk. Multivariate logistic regression analysis was used to determine the independent predictors of early stroke and to delineate the association between the surgical approach and the chronologic distribution of the onset of stroke.ResultsStroke occurred in 217 patients (2%, n = 10,573). A total of 44 (20%) and 173 (80%) of these patients had stroke after off-pump CABG and on-pump CABG, respectively. The median time for the onset of stroke was two days (range 0 to 11 days) after on-pump CABG versus four days (range 0 to 14 days) after off-pump CABG (p < 0.01). On-pump CABG was associated with a higher risk of early stroke (odds ratio 5.3, 95% confidence interval 2.6 to 10.9; p < 0.01) compared with off-pump CABG.ConclusionsCompared with off-pump CABG, on-pump CABG is associated with an earlier onset of postoperative stroke during the recovery phase, suggesting different mechanisms in the pathogenesis of stroke between the two surgical approaches

    Magnetic and quantum entanglement properties of the distorted diamond chain model for azurite

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    We present the results of magnetic properties and entanglement of the distorted diamond chain model for azurite using pure quantum exchange interactions. The magnetic properties and concurrence as a measure of pairwise thermal entanglement have been studied by means of variational mean-field like treatment based on Gibbs-Bogoliubov inequality. Such a system can be considered as an approximation of the natural material azurite, Cu3(CO3)2(OH)2. For values of exchange parameters, which are taken from experimental results, we study the thermodynamic properties, such as azurite specific heat and magnetic susceptibility. We also have studied the thermal entanglement properties and magnetization plateau of the distorted diamond chain model for azurite

    Using estrus detection patches to optimally time insemination improved pregnancy risk in suckled beef cows enrolled in a fixed-time artificial insemination program

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    Citation: Hill, S. L., Grieger, D. M., Olson, K. C., Jaeger, J. R., Dahlen, C. R., Bridges, G. A., . . . Stevenson, J. S. (2016). Using estrus detection patches to optimally time insemination improved pregnancy risk in suckled beef cows enrolled in a fixed-time artificial insemination program. Journal of Animal Science, 94(9), 3703-3710. doi:10.2527/jas2016-0469A multilocation study examined pregnancy risk (PR) after delaying AI in suckled beef cows from 60 to 75 h when estrus had not been detected by 60 h in response to a 7-d CO-Synch + progesterone insert (CIDR) timed AI (TAI) program (d-7: CIDR insert concurrent with an injection of GnRH; d 0: PGF(2 alpha) injection and removal of CIDR insert; and GnRH injection at TAI [ 60 or 75 h after CIDR removal]). A total of 1,611 suckled beef cows at 15 locations in 9 states (CO, IL, KS, MN, MS, MT, ND, SD, and VA) were enrolled. Before applying the fixed-time AI program, BCS was assessed, and blood samples were collected. Estrus was defined to have occurred when an estrus detection patch was >50% colored (activated). Pregnancy was determined 35 d after AI via transrectal ultrasound. Cows (n = 746) detected in estrus by 60 h (46.3%) after CIDR removal were inseminated and treated with GnRH at AI (Control). Remaining nonestrous cows were allocated within location to 3 treatments on the basis of parity and days postpartum: 1) GnRH injection and AI at 60 h (early-early = EE; n = 292), 2) GnRH injection at 60 h and AI at 75 h (early-delayed = ED; n = 282), or 3) GnRH injection and AI at 75 h (delayed-delayed = DD; n = 291). Control cows had a greater (P < 0.01) PR (64.2%) than other treatments (EE = 41.7%, ED = 52.8%, DD = 50.0%). Use of estrus detection patches to delay AI in cows not in estrus by 60 h after CIDR insert removal (ED and DD treatments) increased (P < 0.05) PR to TAI when compared with cows in the EE treatment. More (P < 0.001) cows that showed estrus by 60 h conceived to AI at 60 h than those not showing estrus (64.2% vs. 48.1%). Approximately half (49.2%) of the cows not in estrus by 60 h had activated patches by 75 h, resulting in a greater (P < 0.05) PR than their nonestrous herd mates in the EE (46.1% vs. 34.5%), ED (64.2% vs. 39.2%), and DD (64.8% vs. 31.5%) treatments, respectively. Overall, cows showing estrus by 75 h (72.7%) had greater (P < 0.001) PR to AI (61.3% vs. 37.9%) than cows not showing estrus. Use of estrus detection patches to allow for a delayed AI in cows not in estrus by 60 h after removal of the CIDR insert improved PR to TAI by optimizing the timing of the AI in those cows

    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
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