523 research outputs found

    Anticancer and Immunomodulatory Activities of a Novel Water-Soluble Derivative of Ellipticine

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    Cancer still remains a major public health concern around the world and the search for new potential antitumor molecules is essential for fighting the disease. This study evaluated the anticancer and immunomodulatory potential of the newly synthetized ellipticine derivate: sodium bromo-5,11-dimethyl-6H-pyrido[4,3-b]carbazole-7-sulfonate (Br-Ell-SO3Na). It was prepared by the chlorosulfonation of 9-bromoellipticine. The ellipticine-7-sulfonic acid itself is not soluble, but its saponification with sodium hydroxide afforded a water-soluble sodium salt. The cytotoxicity of Br-Ell-SO3Na was tested against cancerous (K562 cell line) and non-cancerous cells (Vero cell line and human peripheral blood mononuclear cells (PBMC)) using a Methylthiazoletetrazolium (MTT) assay. Cell cycle arrest was assessed by flow cytometry and the immunomodulatory activity was analyzed through an enzyme-linked immunosorbent assay (ELISA). The results showed that the Br-Ell-SO3Na molecule has specific anticancer activity (IC50 = 35 µM) against the K562 cell line, once no cytotoxicity effect was verified against non-cancerous cells. Cell cycle analysis demonstrated that K562 cells treated with Br-Ell-SO3Na were arrested in the phase S. Moreover, the production of IL-6 increased and the expression of IL-8 was inhibited in the human PBMC treated with Br-Ell-SO3Na. The results demonstrated that Br-Ell-SO3Na is a promising anticancer molecule attested by its noteworthy activity against the K562 tumor cell line and immunomodulatory activity in human PBMC cells

    Measurement of the photon polarization in Λb→Λγ\Lambda_b \to \Lambda \gamma decays

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    The photon polarization in b→sγb \to s \gamma transitions is measured for the first time in radiative b-baryon decays exploiting the unique spin structure of Λb→Λγ\Lambda_b \to \Lambda \gamma decays. A data sample corresponding to an integrated luminosity of 6  fb−16\;fb^{-1} collected by the LHCb experiment in pppp collisions at a center-of-mass energy of 13  TeV13\;TeV is used. The photon polarization is measured to be αγ=0.82 − 0.26 − 0.13 + 0.17 + 0.04\alpha_{\gamma}= 0.82^{\,+\,0.17\,+\,0.04}_{\,-\,0.26\,-\,0.13}, where the first uncertainty is statistical and the second systematic. This result is in agreement with the Standard Model prediction and previous measurements in b-meson decays. Charge-parity breaking effects are studied for the first time in this observable and found to be consistent with CPCP symmetry.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-2021-030.html (LHCb public pages

    Angular analysis of D0→π+π−μ+μ−D^0 \to \pi^+\pi^-\mu^+\mu^- and D0→K+K−μ+μ−D^0 \to K^+K^-\mu^+\mu^- decays and search for CPCP violation

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    The first full angular analysis and an updated measurement of the decay-rate CPCP asymmetry of the D0→π+π−μ+μ−D^0 \to \pi^+\pi^-\mu^+\mu^- and D0→K+K−μ+μ−D^0 \to K^+K^-\mu^+\mu^- decays are reported. The analysis uses proton-proton collision data collected with the LHCb detector at centre-of-mass energies of 7, 8 and 13 TeV. The data set corresponds to an integrated luminosity of 9 fb−1^{-1}. The full set of CPCP-averaged angular observables and their CPCP asymmetries are measured as a function of the dimuon invariant mass. The results are consistent with expectations from the standard model and with CPCP symmetry.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2021-035.html (LHCb public pages

    Observation of the doubly charmed baryon decay Ξcc++→Ξc′+π+

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    The Ξcc++→Ξc′+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++→Ξc′+π+ decay is reconstructed partially, where the photon from the Ξc′+→Ξc+γ decay is not reconstructed and the pK−π+ final state of the Ξc+ baryon is employed. The Ξcc++→Ξc′+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.

    Study of the psi(2)(3823) and chi(c1)(3872) states in B+->(J/psi pi(+)pi(-))K(+)decays

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    The decays B+→J/ψπ+π−K+B^+\rightarrow J/\psi \pi^+ \pi^- K^+ are studied using a data set corresponding to an integrated luminosity of 9fb−1^{-1} collected with the LHCb detector in proton-proton collisions between 2011 and 2018. Precise measurements of the ratios of branching fractions with the intermediate ψ2(3823)\psi_2(3823), χc1(3872)\chi_{c1}(3872) and ψ(2S)\psi(2S) states are reported. The decay of B+→ψ2(3872)K+B^+\rightarrow \psi_2(3872)K^+ with ψ2(3823)→Jψπ+π−\psi_2(3823)\rightarrow J\psi\pi^+\pi^- is observed for the first time with a significance of 5.1 standard deviations. The mass differences between the ψ2(3823)\psi_2(3823), χc1(3872)\chi_{c1}(3872) and ψ(2S)\psi(2S) states are measured to be mχc1(3872)−mψ2(3823)=47.50±0.53±0.13 MeV/c2 ,mψ2(3823)−mψ(2S)=137.98±0.53±0.14 MeV/c2 ,mχc1(3872)−mψ(2S)=185.49±0.06±0.03 MeV/c2 , \begin{array}{rcl} m_{\chi_{c1(3872)}} - m_{\psi_2(3823)} &= & 47.50 \pm 0.53 \pm 0.13\,\mathrm{MeV/}c^2\,, \\ m_{\psi_2(3823)} - m_{\psi(2S)} &= & 137.98 \pm 0.53 \pm 0.14\,\mathrm{MeV/}c^2\,, \\ m_{\chi_{c1}(3872)} - m_{\psi(2S)} &= & 185.49 \pm 0.06 \pm 0.03\,\mathrm{MeV/}c^2\,, \end{array} resulting in the most precise determination of the χc1(3782)\chi_{c1}(3782) mass. The width of the ψ2(3823)\psi_2(3823) state is found to be below 5.2MeV at 90\% confidence level. The Breit-Wigner width of the χc1(3872)\chi_{c1}(3872) state is measured to be Γχc1(3872)BW=0.96−0.18+0.19±0.21MeV, \Gamma^{\mathrm{BW}}_{\chi_{c1}(3872)} = 0.96^{+0.19}_{-0.18}\pm0.21 \mathrm{MeV}, which is inconsistent with zero by 5.5 standard deviations.Comment: 26 pages, 3 figures. All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2020-009.html (LHCb public pages
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