388 research outputs found

    A New Approach to Supramolecular Structure Determination in Pharmaceutical Preparation of Self-Assembling Peptides: A Case Study of Lanreotide Autogel

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    The supramolecular structure in peptides’ prolonged-released gel formulations is the most critical parameter for the determination of the pharmaceutical profile of the drug. Here, we report our investigation on lanreotide Autogel as a case study. For the first time, we describe the use of the pulsed field gradient (PFG) diffusion-ordered spectroscopy (DOSY) magic-angle spinning NMR to characterize the supramolecular self-assembly and molecular mobility of different samples of lanreotide Autogel formulations prepared according to different formulation protocols. The diffusion coefficient was used to calculate the hydrodynamic radii of supramolecular assemblies and build relative molecular models. DOSY data were integrated with NMR imaging (MRI) measurements and atomic force microscopy (AFM) imaging

    Studying the interaction between charm and light-flavor mesons

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    International audienceThe two-particle momentum correlation functions between charm mesons (D±\mathrm{D^{*\pm}} and D±\mathrm{D}^\pm) and charged light-flavor mesons (π±\pi^{\pm} and K±^{\pm}) in all charge-combinations are measured for the first time by the ALICE Collaboration in high-multiplicity proton-proton collisions at a center-of-mass energy of s=13\sqrt{s} =13 TeV. For DK\mathrm{DK} and DK\mathrm{D^*K} pairs, the experimental results are in agreement with theoretical predictions of the residual strong interaction based on quantum chromodynamics calculations on the lattice and chiral effective field theory. In the case of Dπ\mathrm{D}\pi and Dπ\mathrm{D^*}\pi pairs, tension between the calculations including strong interactions and the measurement is observed. For all particle pairs, the data can be adequately described by Coulomb interaction only, indicating a shallow interaction between charm and light-flavor mesons. Finally, the scattering lengths governing the residual strong interaction of the Dπ\mathrm{D}\pi and Dπ\mathrm{D^*}\pi systems are determined by fitting the experimental correlation functions with a model that employs a Gaussian potential. The extracted values are small and compatible with zero

    Systematic study of flow vector decorrelation in sNN=5.02\mathbf{\sqrt{\textit{s}_{_{\bf NN}}}=5.02} TeV Pb-Pb collisions

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    International audienceMeasurements of the pTp_{\rm T}-dependent flow vector fluctuations in Pb-Pb collisions at sNN=5.02 TeV\sqrt{s_{_{\rm NN}}} = 5.02~\mathrm{TeV} using azimuthal correlations with the ALICE experiment at the LHC are presented. A four-particle correlation approach [1] is used to quantify the effects of flow angle and magnitude fluctuations separately. This paper extends previous studies to additional centrality intervals and provides measurements of the pTp_{\rm T}-dependent flow vector fluctuations at sNN=5.02 TeV\sqrt{s_{_{\rm NN}}} = 5.02~\mathrm{TeV} with two-particle correlations. Significant pTp_{\rm T}-dependent fluctuations of the V2\vec{V}_{2} flow vector in Pb-Pb collisions are found across different centrality ranges, with the largest fluctuations of up to \sim15% being present in the 5% most central collisions. In parallel, no evidence of significant pTp_{\rm T}-dependent fluctuations of V3\vec{V}_{3} or V4\vec{V}_{4} is found. Additionally, evidence of flow angle and magnitude fluctuations is observed with more than 5σ5\sigma significance in central collisions. These observations in Pb-Pb collisions indicate where the classical picture of hydrodynamic modeling with a common symmetry plane breaks down. This has implications for hard probes at high pTp_{\rm T}, which might be biased by pTp_{\rm T}-dependent flow angle fluctuations of at least 23% in central collisions. Given the presented results, existing theoretical models should be re-examined to improve our understanding of initial conditions, quark--gluon plasma (QGP) properties, and the dynamic evolution of the created system

    Measurement of Ωc0\Omega^0_{\rm c} baryon production and branching-fraction ratio BR(Ωc0Ωe+νe)/BR(Ωc0Ωπ+){\rm BR(\Omega^0_c \rightarrow \Omega^- e^+\nu_e)} / {\rm BR(\Omega^0_c \rightarrow \Omega^- \pi^+)} in pp collisions at s\sqrt{s} = 13 TeV

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    International audienceThe inclusive production of the charm-strange baryon Ωc0\Omega^{0}_{\rm c} is measured for the first time via its semileptonic decay into Ωe+νe\Omega^{-}\rm e^{+}\nu_{e} at midrapidity (y<0.8|y|<0.8) in proton-proton (pp) collisions at the centre-of-mass energy s=13\sqrt{s}=13 TeV with the ALICE detector at the LHC. The transverse momentum (pTp_{\rm T}) differential cross section multiplied by the branching ratio is presented in the interval 2<pT<12 GeV/c2<p_{\rm T}<12~{\rm GeV}/c. The branching-fraction ratio BR(Ωc0Ωe+νe)/BR(Ωc0Ωπ+){\rm BR}(\Omega^0_{\rm c} \rightarrow \Omega^{-}{\rm e}^{+}\nu_{\rm e})/ {\rm BR}(\Omega^0_{\rm c} \rightarrow \Omega^{-}{\pi}^{+}) is measured to be 1.12 ±\pm 0.22 (stat.) ±\pm 0.27 (syst.). Comparisons with other experimental measurements, as well as with theoretical calculations, are presented

    Exclusive four pion photoproduction in ultraperipheral Pb-Pb collisions at sNN=5.02\sqrt{s_{\rm NN}} = 5.02 TeV

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    International audienceThe intense photon fluxes from relativistic nuclei provide an opportunity to study photonuclear interactions in ultraperipheral collisions. The measurement of coherently photoproduced π+ππ+π\pi^+\pi^-\pi^+\pi^- final states in ultraperipheral Pb-Pb collisions at sNN=5.02\sqrt{s_{\mathrm{NN}}}=5.02 TeV is presented for the first time. The cross section, dσ\sigma/dyy, times the branching ratio (ρπ+π+ππ\rho\rightarrow \pi^+ \pi^+ \pi^- \pi^-) is found to be 47.8±2.3 (stat.)±7.7 (syst.)47.8\pm2.3~\rm{(stat.)}\pm7.7~\rm{(syst.)} mb in the rapidity interval y<0.5|y| < 0.5. The invariant mass distribution is not well described with a single Breit-Wigner resonance. The production of two interfering resonances, ρ(1450)\rho(1450) and ρ(1700)\rho(1700), provides a good description of the data. The values of the masses (mm) and widths (Γ\Gamma) of the resonances extracted from the fit are m1=1385±14 (stat.)±3 (syst.)m_{1}=1385\pm14~\rm{(stat.)}\pm3~\rm{(syst.)} MeV/c2c^2, Γ1=431±36 (stat.)±82 (syst.)\Gamma_{1}=431\pm36~\rm{(stat.)}\pm82~\rm{(syst.)} MeV/c2c^2, m2=1663±13 (stat.)±22 (syst.)m_{2}=1663\pm13~\rm{(stat.)}\pm22~\rm{(syst.)} MeV/c2c^2 and Γ2=357±31 (stat.)±49 (syst.)\Gamma_{2}=357 \pm31~\rm{(stat.)}\pm49~\rm{(syst.)} MeV/c2c^2, respectively. The measured cross sections times the branching ratios are compared to recent theoretical predictions

    Exclusive four pion photoproduction in ultraperipheral Pb-Pb collisions at sNN=5.02\sqrt{s_{\rm NN}} = 5.02 TeV

    No full text
    International audienceThe intense photon fluxes from relativistic nuclei provide an opportunity to study photonuclear interactions in ultraperipheral collisions. The measurement of coherently photoproduced π+ππ+π\pi^+\pi^-\pi^+\pi^- final states in ultraperipheral Pb-Pb collisions at sNN=5.02\sqrt{s_{\mathrm{NN}}}=5.02 TeV is presented for the first time. The cross section, dσ\sigma/dyy, times the branching ratio (ρπ+π+ππ\rho\rightarrow \pi^+ \pi^+ \pi^- \pi^-) is found to be 47.8±2.3 (stat.)±7.7 (syst.)47.8\pm2.3~\rm{(stat.)}\pm7.7~\rm{(syst.)} mb in the rapidity interval y<0.5|y| < 0.5. The invariant mass distribution is not well described with a single Breit-Wigner resonance. The production of two interfering resonances, ρ(1450)\rho(1450) and ρ(1700)\rho(1700), provides a good description of the data. The values of the masses (mm) and widths (Γ\Gamma) of the resonances extracted from the fit are m1=1385±14 (stat.)±3 (syst.)m_{1}=1385\pm14~\rm{(stat.)}\pm3~\rm{(syst.)} MeV/c2c^2, Γ1=431±36 (stat.)±82 (syst.)\Gamma_{1}=431\pm36~\rm{(stat.)}\pm82~\rm{(syst.)} MeV/c2c^2, m2=1663±13 (stat.)±22 (syst.)m_{2}=1663\pm13~\rm{(stat.)}\pm22~\rm{(syst.)} MeV/c2c^2 and Γ2=357±31 (stat.)±49 (syst.)\Gamma_{2}=357 \pm31~\rm{(stat.)}\pm49~\rm{(syst.)} MeV/c2c^2, respectively. The measured cross sections times the branching ratios are compared to recent theoretical predictions

    Measurement of Ωc0\Omega^0_{\rm c} baryon production and branching-fraction ratio BR(Ωc0Ωe+νe)/BR(Ωc0Ωπ+){\rm BR(\Omega^0_c \rightarrow \Omega^- e^+\nu_e)} / {\rm BR(\Omega^0_c \rightarrow \Omega^- \pi^+)} in pp collisions at s\sqrt{s} = 13 TeV

    No full text
    International audienceThe inclusive production of the charm-strange baryon Ωc0\Omega^{0}_{\rm c} is measured for the first time via its semileptonic decay into Ωe+νe\Omega^{-}\rm e^{+}\nu_{e} at midrapidity (y<0.8|y|<0.8) in proton-proton (pp) collisions at the centre-of-mass energy s=13\sqrt{s}=13 TeV with the ALICE detector at the LHC. The transverse momentum (pTp_{\rm T}) differential cross section multiplied by the branching ratio is presented in the interval 2<pT<12 GeV/c2<p_{\rm T}<12~{\rm GeV}/c. The branching-fraction ratio BR(Ωc0Ωe+νe)/BR(Ωc0Ωπ+){\rm BR}(\Omega^0_{\rm c} \rightarrow \Omega^{-}{\rm e}^{+}\nu_{\rm e})/ {\rm BR}(\Omega^0_{\rm c} \rightarrow \Omega^{-}{\pi}^{+}) is measured to be 1.12 ±\pm 0.22 (stat.) ±\pm 0.27 (syst.). Comparisons with other experimental measurements, as well as with theoretical calculations, are presented

    Systematic study of flow vector decorrelation in sNN=5.02\mathbf{\sqrt{\textit{s}_{_{\bf NN}}}=5.02} TeV Pb-Pb collisions

    No full text
    International audienceMeasurements of the pTp_{\rm T}-dependent flow vector fluctuations in Pb-Pb collisions at sNN=5.02 TeV\sqrt{s_{_{\rm NN}}} = 5.02~\mathrm{TeV} using azimuthal correlations with the ALICE experiment at the LHC are presented. A four-particle correlation approach [1] is used to quantify the effects of flow angle and magnitude fluctuations separately. This paper extends previous studies to additional centrality intervals and provides measurements of the pTp_{\rm T}-dependent flow vector fluctuations at sNN=5.02 TeV\sqrt{s_{_{\rm NN}}} = 5.02~\mathrm{TeV} with two-particle correlations. Significant pTp_{\rm T}-dependent fluctuations of the V2\vec{V}_{2} flow vector in Pb-Pb collisions are found across different centrality ranges, with the largest fluctuations of up to \sim15% being present in the 5% most central collisions. In parallel, no evidence of significant pTp_{\rm T}-dependent fluctuations of V3\vec{V}_{3} or V4\vec{V}_{4} is found. Additionally, evidence of flow angle and magnitude fluctuations is observed with more than 5σ5\sigma significance in central collisions. These observations in Pb-Pb collisions indicate where the classical picture of hydrodynamic modeling with a common symmetry plane breaks down. This has implications for hard probes at high pTp_{\rm T}, which might be biased by pTp_{\rm T}-dependent flow angle fluctuations of at least 23% in central collisions. Given the presented results, existing theoretical models should be re-examined to improve our understanding of initial conditions, quark--gluon plasma (QGP) properties, and the dynamic evolution of the created system
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