163 research outputs found

    Predicted ΛΛˉ\Lambda\bar{\Lambda} and ΞΞˉ+\Xi^-\bar{\Xi}^+ decay modes of the charmoniumlike Y(4230)Y(4230)

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    In this work, we predict the light hadronic decay channels Y(4230)ΛΛˉY(4230)\to\Lambda\bar{\Lambda} and ΞΞˉ+\Xi^-\bar{\Xi}^+ when treating the Y(4230)Y(4230) as a vector charmonium state. By the hadronic loop mechanism, the branching ratios of the Y(4230)ΛΛˉY(4230)\to\Lambda\bar{\Lambda} and ΞΞˉ+\Xi^-\bar{\Xi}^+ processes are calculated. In addition, we discuss the possibility of carrying out the search for the signal of the Y(4230)Y(4230) through ΛΛˉ\Lambda\bar{\Lambda} and ΞΞˉ+\Xi^-\bar{\Xi}^+ channels from the e+ee^+e^- annihilation. Assuming Y(4230)Y(4230) exist in ΛΛˉ\Lambda\bar{\Lambda} and ΞΞˉ+\Xi^-\bar{\Xi}^+ channel, we also present the time-like electromagnetic form factors (EMFFs) at s=mY(4230)\sqrt{s}=m_{Y(4230)}.Comment: 8 pages, 9 figures and 2 table

    Mobility of TX100 suspended multiwalled carbon nanotubes (MWCNTs) and the facilitated transport of phenanthrene in real soil columns

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    AbstractThe transport behavior of TX100 suspended multiwalled carbon nanotubes (MWCNTs) through different soil columns as well as their effects on the mobility of phenanthrene was systematically studied. Results showed that the mobility of MWCNTs varied with soils, which was found to be correlated positively to the average soil particle diameters and soil sand contents, while correlated negatively to soil clay contents. The retention of MWCNTs on soil columns is most likely due to surface deposition and physical straining. Co-transport of phenanthrene with MWCNTs was tested in three selected soils (soil HB, DX and BJ), where MWCNTs could act as carriers of phenanthrene and enhance the mobility of phenanthrene in soils. However, during passing through the soil columns phenanthrene initially adsorbed onto MWCNTs could be partially “stripped” off. In soil with the lowest phenanthrene sorption affinity and highest water velocity (soil HB), only 8.5% phenanthrene was desorbed during transport, suggesting that a strong MWCNT-associated phenanthrene mobile may occur in this soil. More than 80% of phenanthrene was stripped off in soils with higher sorption affinity (soil DX and BJ), indicating the limitation of the co-transport of phenanthrene and MWCNTs in such soils

    Insecticidal effect of volatile compounds from plant materials of Murraya exotica against Red Imported Fire Ant Workers

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    The effect of volatile compounds from the mashed fresh, fallen, and dried leaves of Murraya exotica on the behavior of red imported fire ant (Solenopsis invicta, RIFA) workers was investigated by fumigation toxicity bioassay. The volatile compounds from different mashed leaves (fresh, fallen, and dried leaves) of M. exotica were collected by solid-phase microextraction and identified by gas chromatography–mass spectrometry. β-Caryophyllene, α-cedrene, α-copaene, β-cubebene, and germacrene D were identified as major components of the volatile compounds. In exposure time from 1 d to 9 d, the mortality of RIFA increased from 5.00% to 100.00% (fresh leaves), 11.67% to 93.33% (fallen leaves), and 15.00% to 83.33% (dried leaves) in minor workers, whereas in major workers, the increases were from 13.33% to 93.33% (fresh leaves), 6.67% to 83.33% (fallen leaves), and 10.00% to 60.00% (dried leaves). The volatile compounds reduced the walking and grasping abilities and aggregation rate of RIFA workers. Results indicate that mashed leaves of M. exotica have potential for controlling RIFA

    Dietary phytochemicals, HDAC inhibition, and DNA damage/repair defects in cancer cells

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    Genomic instability is a common feature of cancer etiology. This provides an avenue for therapeutic intervention, since cancer cells are more susceptible than normal cells to DNA damaging agents. However, there is growing evidence that the epigenetic mechanisms that impact DNA methylation and histone status also contribute to genomic instability. The DNA damage response, for example, is modulated by the acetylation status of histone and non-histone proteins, and by the opposing activities of histone acetyltransferase and histone deacetylase (HDAC) enzymes. Many HDACs overexpressed in cancer cells have been implicated in protecting such cells from genotoxic insults. Thus, HDAC inhibitors, in addition to unsilencing tumor suppressor genes, also can silence DNA repair pathways, inactivate non-histone proteins that are required for DNA stability, and induce reactive oxygen species and DNA double-strand breaks. This review summarizes how dietary phytochemicals that affect the epigenome also can trigger DNA damage and repair mechanisms. Where such data is available, examples are cited from studies in vitro and in vivo of polyphenols, organosulfur/organoselenium compounds, indoles, sesquiterpene lactones, and miscellaneous agents such as anacardic acid. Finally, by virtue of their genetic and epigenetic mechanisms, cancer chemopreventive agents are being redefined as chemo- or radio-sensitizers. A sustained DNA damage response coupled with insufficient repair may be a pivotal mechanism for apoptosis induction in cancer cells exposed to dietary phytochemicals. Future research, including appropriate clinical investigation, should clarify these emerging concepts in the context of both genetic and epigenetic mechanisms dysregulated in cancer, and the pros and cons of specific dietary intervention strategies

    Observation of a resonant structure near the Ds+DsD_s^+ D_s^- threshold in the B+Ds+DsK+B^+\to D_s^+ D_s^- K^+ decay

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    An amplitude analysis of the B+Ds+DsK+B^+\to D_s^+ D_s^- K^+ decay is carried out to study for the first time its intermediate resonant contributions, using proton-proton collision data collected with the LHCb detector at centre-of-mass energies of 7, 8 and 13 TeV. A near-threshold peaking structure, referred to as X(3960)X(3960), is observed in the Ds+DsD_s^+ D_s^- invariant-mass spectrum with significance greater than 12 standard deviations. The mass, width and the quantum numbers of the structure are measured to be 3956±5±103956\pm5\pm10 MeV, 43±13±843\pm13\pm8 MeV and JPC=0++J^{PC}=0^{++}, respectively, where the first uncertainties are statistical and the second systematic. The properties of the new structure are consistent with recent theoretical predictions for a state composed of ccˉssˉc\bar{c}s\bar{s} quarks. Evidence for an additional structure is found around 4140 MeV in the Ds+DsD_s^+ D_s^- invariant mass, which might be caused either by a new resonance with the 0++0^{++} assignment or by a J/ψϕDs+DsJ/\psi \phi\leftrightarrow D_s^+ D_s^- coupled-channel effect.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-018.html (LHCb public pages

    First observation of a doubly charged tetraquark and its neutral partner

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    A combined amplitude analysis is performed for the decays B0D0Ds+πB^0 \rightarrow \overline{D}^0 D^+_s\pi^- and B+DDs+π+B^+\rightarrow D^- D^+_s\pi^+, which are related by isospin symmetry. The analysis is based on data collected by the LHCb detector in proton-proton collisions at center-of-mass energies of 7, 8 and 13TeV\,\rm{TeV}. The full data sample corresponds to an integrated luminosity of 9fb1\,\rm{fb^{-1}}. Two new resonant states with masses of 2.908±0.011±0.020GeV2.908\pm0.011\pm0.020\,\rm{GeV} and widths of 0.136±0.023±0.011GeV0.136\pm0.023\pm0.011\,\rm{GeV} are observed, which decay to Ds+π+D^+_s\pi^+ and Ds+πD^+_s\pi^- respectively. The former state indicates the first observation of a doubly charged open-charm tetraquark state with minimal quark content [csˉudˉ][c\bar{s}u\bar{d}], and the latter state is a neutral tetraquark composed of [csˉuˉd][c\bar{s}\bar{u}d] quarks. Both states are found to have spin-parity 0+0^+, and their resonant parameters are consistent with each other, which suggests that they belong to an isospin triplet.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-026.html (LHCb public pages

    Pan-cancer analysis of whole genomes

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    Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale(1-3). Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter(4); identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation(5,6); analyses timings and patterns of tumour evolution(7); describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity(8,9); and evaluates a range of more-specialized features of cancer genomes(8,10-18).Peer reviewe

    Precise determination of the B-s(0)-B-s(-0) oscillation frequency

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    Mesons comprising a beauty quark and a strange quark can oscillate between particle (B0s) and antiparticle (B0s) flavour eigenstates, with a frequency given by the mass difference between heavy and light mass eigenstates, deltams. Here we present ameasurement of deltams using B0s2DsPi decays produced in proton-proton collisions collected with the LHCb detector at the Large Hadron Collider. The oscillation frequency is found to be deltams = 17.7683 +- 0.0051 +- 0.0032 ps-1, where the first uncertainty is statistical and the second systematic. This measurement improves upon the current deltams precision by a factor of two. We combine this result with previous LHCb measurements to determine deltams = 17.7656 +- 0.0057 ps-1, which is the legacy measurement of the original LHCb detector.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2021-005.html (LHCb public pages

    Angular Analysis of the B+ -> K*(+)mu(+) mu(-) Decay

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    We present an angular analysis of the B + → K * + ( → K 0 S π + ) μ + μ − decay using 9     fb − 1 of p p collision data collected with the LHCb experiment. For the first time, the full set of C P -averaged angular observables is measured in intervals of the dimuon invariant mass squared. Local deviations from standard model predictions are observed, similar to those in previous LHCb analyses of the isospin-partner B 0 → K * 0 μ + μ − decay. The global tension is dependent on which effective couplings are considered and on the choice of theory nuisance parameters
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