2,842 research outputs found

    Mass spectra of hidden heavy-flavor tetraquarks with two and four heavy quarks

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    Inspired by the observation of the X(6900)X(6900) by LHCb and the X(6600)X(6600) (with mass 6552±106552\pm 10 ±12\pm 12 MeV) recently by CMS and ATLAS experiments of the LHC in the di-J/ΨJ/\Psi invariant mass spectrum, we systemically study masses of all ground-state configurations of the hidden heavy-flavor tetraquarks q1Q2qˉ3Qˉ4q_{1}Q_{2}\bar{q}_{3}\bar{Q}_{4} and Q1Q2Qˉ3Qˉ4Q_{1}Q_{2}\bar{Q}_{3}\bar{Q}_{4} (Q=c,bQ=c,b;q=u,d,sq=u,d,s) contaning two and four heavy quarks in the MIT bag model with chromomagnetic interaction and enhanced binding energy. Considering color-spin mixing due to chromomagnetic interaction, our mass computation indicates that the observed X(6600)X(6600) is likely to be the 0++0^{++} ground states of hidden-charm tetraquark cccˉcˉcc\bar{c}\bar{c} with computed masses 65726572 MeV, which has a 0++0^{++} color partner around 64696469 MeV. The fully bottom system of tetraquark bbbˉbˉbb\bar{b}\bar{b} has masses of 19685 MeV and 19717 MeV for the the 0++0^{++} ground states. Further computation is given to the tetraquark systems scsˉcˉsc\bar{s}\bar{c}, sbsˉbˉsb\bar{s}\bar{b}, cbcˉbˉcb\bar{c}\bar{b}, ncnˉcˉnc\bar{n}\bar{c} and nbnˉbˉnb\bar{n}\bar{b}, suggesting that the Zc(4200)Z_{c}(4200) is the tetraquark ncnˉcˉnc\bar{n}\bar{c} with JPC=1+J^{PC}=1^{+-}. All of these tetraquarks are above their lowest thresholds of two mesons and unstable against the strong decays

    Harmonics of Parton Saturation in Lepton-Jet Correlations at the EIC

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    Parton saturation is one of the most intriguing phenomena in the high energy nuclear physics research frontier, especially in the upcoming era of the Electron-Ion Collider (EIC). The lepton-jet correlation in deep inelastic scattering provides us with a new gateway to the parton saturation at the EIC. In particular, we demonstrate that azimuthal angle anisotropies of the lepton-jet correlation are sensitive to the strength of the saturation momentum in the EIC kinematic region. In contrast to the predictions based on the collinear framework calculation, significant nuclear modification of the anisotropies is observed when we compare the saturation physics results in e + p and e + Au scatterings. By measuring these harmonic coefficients at the EIC, one can conduct quantitative analysis in different collisional systems and unveil compelling evidence for saturation effects.Comment: 7 pages, 3 figure

    Inhibition of USP7 activity selectively eliminates senescent cells in part via restoration of p53 activity.

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    The accumulation of senescent cells (SnCs) is a causal factor of various age-related diseases as well as some of the side effects of chemotherapy. Pharmacological elimination of SnCs (senolysis) has the potential to be developed into novel therapeutic strategies to treat these diseases and pathological conditions. Here we show that ubiquitin-specific peptidase 7 (USP7) is a novel target for senolysis because inhibition of USP7 with an inhibitor or genetic depletion of USP7 by RNA interference induces apoptosis selectively in SnCs. The senolytic activity of USP7 inhibitors is likely attributable in part to the promotion of the human homolog of mouse double minute 2 (MDM2) ubiquitination and degradation by the ubiquitin-proteasome system. This degradation increases the levels of p53, which in turn induces the pro-apoptotic proteins PUMA, NOXA, and FAS and inhibits the interaction of BCL-XL and BAK to selectively induce apoptosis in SnCs. Further, we show that treatment with a USP7 inhibitor can effectively eliminate SnCs and suppress the senescence-associated secretory phenotype (SASP) induced by doxorubicin in mice. These findings suggest that small molecule USP7 inhibitors are novel senolytics that can be exploited to reduce chemotherapy-induced toxicities and treat age-related diseases

    TF-IDF Based Contextual Post-Filtering Recommendation Algorithm in Complex Interactive Situations of Online to Offline: An Empirical Study

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    O2O accelerates the integration of online and offline, promotes the upgrading of industrial structure and consumption pattern, meanwhile brings the information overload problem. This paper develops a post-context filtering recommendation algorithm based on TF-IDF, which improves the existing algorithms. Combined with contextual association probability and contextual universal importance, a contextual preference prediction model was constructed to adjust the initial score of the traditional recommendation combined with item category preference to generate the final result. The example of the catering industry shows that the proposed algorithm is more effective than the improved algorithm

    Information Entropy Theory Based Recognition of the Validity of Contextual Information of Restaurants: An Empirical Study

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    Contextual information plays a key role in personalized recommendations. However, not all contextual information plays a positive role in personalized recommendations. Therefore, it is critical to identify the effective contextual information to realize personalized recommendations. This study aims to develop a set of feasible context importance calculation methods that can identify effective contextual information in different application scenarios. The information entropy of each contextual dimension is calculated, and the validity of the context compared according to the magnitude of its entropy is determined based on the informational entropy theory. Subsequently, this approach is applied to hotel and catering service data to determine the valid context in the dining domain. The experimental results indicate that location, work-rest condition, weather, mood and companionship considerably influence consumers’ behaviour and decisions in a catering environment, and the user preference in such contexts should be carefully considered

    Transitioning360: Content-aware NFoV Virtual Camera Paths for 360° Video Playback

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    Are CD4+CD25-Foxp3+ cells in untreated new-onset lupus patients regulatory T cells?

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    Introduction: Our previous study has reported that, in patients with untreated new-onset lupus (UNOL), there was an abnormal increase in the number of CD4CD25Foxp3T cells that correlated with disease activity and significantly decreased after treatment. However, little is known about the nature of this cell entity. The aim of this study was to explore the nature of abnormally increased CD4CD25Foxp3T cells in UNOL patients.Methods: The expressions of surface (CD4, CD25, CD127, chemokine receptor 4 [CCR4], glucocorticoid-induced tumor necrosis factor receptor [GITR], and cytotoxic T lymphocyte-associated antigen 4 [CTLA-4]) and intracellular (Foxp3) molecules as well as cytokine synthesis of peripheral blood mononuclear cells from 22 UNOL patients were analyzed by flow cytometry. The proliferative and suppressive capacities of different T-cell subgroups from UNOL patients were also assessed.Results: In UNOL patients, the percentages of CD127in CD25, CD25, and CD25subpopulations of CD4Foxp3T cells were 93.79% ± 3.48%, 93.66% ± 2.31%, and 91.98% ± 2.14%, respectively (P > 0.05), whereas the expressions of Foxp3 showed significant differences in CD25(91.38% ± 2.57%), CD25(71.89% ± 3.31%), and CD25(9.02% ± 2.21%) subpopulations of CD4CD127T cells (P < 0.01). The expressions of surface CCR4, GITR, and CTLA-4 on CD4CD25Foxp3T cells were significantly less than CD4CD25Foxp3T cells (P < 0.05). Moreover, unlike CD4CD25Foxp3T cells, CD4CD25Foxp3T cells also synthesized interferon-gamma, interleukin (IL)-4, IL-2, and IL-17 (P < 0.05), though less than CD4CD25Foxp3T cells. The suppressive capacity was most prominent in CD4CD25CD127, followed by CD4CD25CD127. CD4CD25CD127T cells showed the least suppressive capacity, which was similar to the effector T cells.Conclusions: CD4CD25Foxp3T cells in UNOL patients are different from regulatory T cells, both phenotypically and functionally. CD127 is not an appropriate surface marker for intracellular Foxp3 in CD4CD25T cells
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