1,341 research outputs found

    Obese adolescents exhibit a constant ratio of GH isoforms after whole body vibration and maximal voluntary contractions

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    Background: Growth hormone (GH) is a heterogeneous protein composed of several molecular isoforms, the most abundant ones being the 22kDa- and 20kDa-GH. Exercise-induced secretion of GH isoforms has been extensively investigated in normal-weight individuals due to antidoping purposes, particularly recombinant human GH (rhGH) abuse. On the other hand, the evaluation of exercise-induced responses in GH isoforms has never been performed in obese subjects.Methods: The acute effects of whole body vibration (WBV) or maximal voluntary contraction (MVC) alone and the combination of MVC with WBV (MVC+WBV) on circulating levels of 22kDa- and 20kDa-GH were evaluated in 8 obese male adolescents [mean ageSD: 17.13.3yrs.;weight: 107.4 +/- 17.8kg;body mass index (BMI): 36.5 +/- 6.6kg/m(2);BMI standard deviation score (SDS): 3.1 +/- 0.6].Results: MVC (alone or combined with WBV) significantly stimulated 22kDa- and 20kDa-GH secretion, while WBV alone was ineffective. In particular, 22kDa- and 20kDa-GH peaks were significantly higher after MVC+WBV and MVC than WBV. In addition, 22kDa-GH (but not 20kDa-GH) peak was significantly higher after MVC+WBV than MVC. Importantly, the ratio of circulating levels of 22kDa- to 20kDa-GH was constant throughout the time window of evaluation after exercise and similar among the three different protocols of exercise.Conclusions The results of the present study confirm the ability of MVC, alone and in combination with WBV, to stimulate both 22kDa- and 20kDa-GH secretion in obese patients, these responses being related to the exercise workload. Since the ratio of 22kDa- to 20kDa-GH is constant after exercise and independent from the protocols of exercise as in normal-weight subjects, hyposomatotropism in obesity does not seem to depend on an unbalance of circulating GH isoforms. Since the present study was carried out in a small cohort of obese sedentary adolescents, these preliminary results should be confirmed in further future studies enrolling overweight/obese subjects with a wider age range

    Search for the standard model Higgs boson at LEP

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    CurrĂ­culo e RelaçÔes Étnico-Raciais: o Estado da Arte

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    Este artigo apresenta a sistematização e a anĂĄlise dos 38 artigos, 13 teses e 50 dissertaçÔes da Categoria CurrĂ­culo. Inicialmente, demonstraremos os resultados do exame das teses e das dissertaçÔes. Em seguida, refletiremos acerca dos artigos. Para a leitura e anĂĄlise dos artigos e da produção discente, utilizamos como subsĂ­dio os referenciais da anĂĄlise de conteĂșdo, por meio da anĂĄlise categorial (BARDIN, 2008). Ao final, apresentaremos os caminhos abertos para pesquisas futuras e as recomendaçÔes da produção investigada para a implementação da Lei nÂș 10.639/2003

    Measurement of antiproton production from antihyperon decays in pHe collisions at √sNN=110GeV

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    The interpretation of cosmic antiproton flux measurements from space-borne experiments is currently limited by the knowledge of the antiproton production cross-section in collisions between primary cosmic rays and the interstellar medium. Using collisions of protons with an energy of 6.5 TeV incident on helium nuclei at rest in the proximity of the interaction region of the LHCb experiment, the ratio of antiprotons originating from antihyperon decays to prompt production is measured for antiproton momenta between 12 and 110GeV\!/c . The dominant antihyperon contribution, namely Λ¯ → pÂŻ π+ decays from promptly produced Λ¯ particles, is also exclusively measured. The results complement the measurement of prompt antiproton production obtained from the same data sample. At the energy scale of this measurement, the antihyperon contributions to antiproton production are observed to be significantly larger than predictions of commonly used hadronic production models

    Studies of η\eta and ηâ€Č\eta' production in pppp and ppPb collisions

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    The production of η\eta and ηâ€Č\eta' mesons is studied in proton-proton and proton-lead collisions collected with the LHCb detector. Proton-proton collisions are studied at center-of-mass energies of 5.025.02 and 13 TeV13~{\rm TeV}, and proton-lead collisions are studied at a center-of-mass energy per nucleon of 8.16 TeV8.16~{\rm TeV}. The studies are performed in center-of-mass rapidity regions 2.5<yc.m.<3.52.5<y_{\rm c.m.}<3.5 (forward rapidity) and −4.0<yc.m.<−3.0-4.0<y_{\rm c.m.}<-3.0 (backward rapidity) defined relative to the proton beam direction. The η\eta and ηâ€Č\eta' production cross sections are measured differentially as a function of transverse momentum for 1.5<pT<10 GeV1.5<p_{\rm T}<10~{\rm GeV} and 3<pT<10 GeV3<p_{\rm T}<10~{\rm GeV}, respectively. The differential cross sections are used to calculate nuclear modification factors. The nuclear modification factors for η\eta and ηâ€Č\eta' mesons agree at both forward and backward rapidity, showing no significant evidence of mass dependence. The differential cross sections of η\eta mesons are also used to calculate η/π0\eta/\pi^0 cross section ratios, which show evidence of a deviation from the world average. These studies offer new constraints on mass-dependent nuclear effects in heavy-ion collisions, as well as η\eta and ηâ€Č\eta' meson fragmentation.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/Publications/p/LHCb-PAPER-2023-030.html (LHCb public pages

    Consistent improvement with eculizumab across muscle groups in myasthenia gravis

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    Observation of the doubly charmed baryon decay Ξcc++→Ξcâ€Č+π+

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    The Ξcc++→Ξcâ€Č+π+ decay is observed using proton-proton collisions collected by the LHCb experiment at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.4 fb−1. The Ξcc++→Ξcâ€Č+π+ decay is reconstructed partially, where the photon from the Ξcâ€Č+→Ξc+Îł decay is not reconstructed and the pK−π+ final state of the Ξc+ baryon is employed. The Ξcc++→Ξcâ€Č+π+branching fraction relative to that of the Ξcc++→Ξc+π+ decay is measured to be 1.41 ± 0.17 ± 0.10, where the first uncertainty is statistical and the second systematic. [Figure not available: see fulltext.

    Fraction of χc\chi_c decays in prompt J/ψJ/\psi production measured in pPb collisions at sNN=8.16\sqrt{s_{NN}}=8.16 TeV

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    The fraction of χc1\chi_{c1} and χc2\chi_{c2} decays in the prompt J/ψJ/\psi yield, Fχc=σχc→J/ψ/σJ/ψF_{\chi c}=\sigma_{\chi_c \to J/\psi}/\sigma_{J/\psi}, is measured by the LHCb detector in pPb collisions at sNN=8.16\sqrt{s_{NN}}=8.16 TeV. The study covers the forward (1.5<y∗<4.01.5<y^*<4.0) and backward (−5.0<y∗<−2.5-5.0<y^*<-2.5) rapidity regions, where y∗y^* is the J/ψJ/\psi rapidity in the nucleon-nucleon center-of-mass system. Forward and backward rapidity samples correspond to integrated luminosities of 13.6 ±\pm 0.3 nb−1^{-1} and 20.8 ±\pm 0.5 nb−1^{-1}, respectively. The result is presented as a function of the J/ψJ/\psi transverse momentum pT,J/ψp_{T,J/\psi} in the range 1<pT,J/ψ<20<p_{T, J/\psi}<20 GeV/cc. The FχcF_{\chi c} fraction at forward rapidity is compatible with the LHCb measurement performed in pppp collisions at s=7\sqrt{s}=7 TeV, whereas the result at backward rapidity is 2.4 σ\sigma larger than in the forward region for 1<pT,J/ψ<31<p_{T, J/\psi}<3 GeV/cc. The increase of FχcF_{\chi c} at low pT,J/ψp_{T, J/\psi} at backward rapidity is compatible with the suppression of the ψ\psi(2S) contribution to the prompt J/ψJ/\psi yield. The lack of in-medium dissociation of χc\chi_c states observed in this study sets an upper limit of 180 MeV on the free energy available in these pPb collisions to dissociate or inhibit charmonium state formation.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2023-028.html (LHCb public pages

    Enhanced production of Λb0\Lambda_{b}^{0} baryons in high-multiplicity pppp collisions at s=13\sqrt{s} = 13 TeV

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    The production rate of Λb0\Lambda_{b}^{0} baryons relative to B0B^{0} mesons in pppp collisions at a center-of-mass energy s=13\sqrt{s} = 13 TeV is measured by the LHCb experiment. The ratio of Λb0\Lambda_{b}^{0} to B0B^{0} production cross-sections shows a significant dependence on both the transverse momentum and the measured charged-particle multiplicity. At low multiplicity, the ratio measured at LHCb is consistent with the value measured in e+e−e^{+}e^{-} collisions, and increases by a factor of ∌2\sim2 with increasing multiplicity. At relatively low transverse momentum, the ratio of Λb0\Lambda_{b}^{0} to B0B^{0} cross-sections is higher than what is measured in e+e−e^{+}e^{-} collisions, but converges with the e+e−e^{+}e^{-} ratio as the momentum increases. These results imply that the evolution of heavy bb quarks into final-state hadrons is influenced by the density of the hadronic environment produced in the collision. Comparisons with a statistical hadronization model and implications for the mechanisms enforcing quark confinement are discussed.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2023-027.html (LHCb public pages
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