ABSTRACT
Radio-loud quasars (RLQs) are more X-ray luminous than predicted by the X-ray–optical/UV relation (i.e. $L_\mathrm{x}\propto L_\mathrm{uv}^\gamma$) for radio-quiet quasars (RQQs). The excess ...X-ray emission depends on the radio-loudness parameter (R) and radio spectral slope (αr). We construct a uniform sample of 729 optically selected RLQs with high fractions of X-ray detections and αr measurements. We find that steep-spectrum radio quasars (SSRQs; αr ≤ −0.5) follow a quantitatively similar $L_\mathrm{x}\propto L_\mathrm{uv}^{\gamma }$ relation as that for RQQs, suggesting a common coronal origin for the X-ray emission of both SSRQs and RQQs. However, the corresponding intercept of SSRQs is larger than that for RQQs and increases with R, suggesting a connection between the radio jets and the configuration of the accretion flow. Flat-spectrum radio quasars (FSRQs; αr > −0.5) are generally more X-ray luminous than SSRQs at given Luv and R, likely involving more physical processes. The emergent picture is different from that commonly assumed where the excess X-ray emission of RLQs is attributed to the jets. We thus perform model selection to compare critically these different interpretations, which prefers the coronal scenario with a corona–jet connection. A distinct jet component is likely important for only a small portion of FSRQs. The corona–jet, disc–corona, and disc–jet connections of RLQs are likely driven by independent physical processes. Furthermore, the corona–jet connection implies that small-scale processes in the vicinity of supermassive black holes, probably associated with the magnetic flux/topology instead of black hole spin, are controlling the radio-loudness of quasars.
Cancer initiating cells (CICs) are responsible for the unrestrained cell growth and chemoresistance of malignant tumors. Histone demethylation has been shown to be crucial for ...self-renewal/differentiation of stem cells, but it remains elusive whether lysine-specific demethylase 1 (LSD1) regulates the stemness properties of CICs. Here we report that the abundant expression of leucine-rich repeat-containing G-protein-coupled receptor 5 (Lgr5) is associated with the progression of hepatocellular carcinoma (HCC). Lgr5(+) HCC cells behave similarly to CICs and are highly tumorigenic and resistant to chemotherapeutic agents. Importantly, Lgr5(+) cells express higher levels of LSD1, which in turn regulates Lgr5 expression and promotes the self-renewal and drug resistance of Lgr5(+) CICs. Mechanistically, LSD1 promotes β-catenin activation by inhibiting the expression of several suppressors of β-catenin signaling, especially Prickle1 and APC in Lgr5(+) CICs, by directly regulating the levels of mono- and di-methylation of histone H3 lysine-4 at the promoters of these genes. Furthermore, LSD1-associated activation of the β-catenin signaling is essential for maintaining the activity of Lgr5(+) CICs. Together, our findings unravel the LSD1/Prickle1/APC/β-catenin signaling axis as a novel molecular circuit regulating the stemness and chemoresistance of hepatic Lgr5(+) CICs and provide potential targets to improve chemotherapeutic efficacies against HCC.
Based on 368.5 pb\(^{-1}\) of \(e^+e^-\) collision data collected at center-of-mass energies 4.914 and 4.946 GeV by the BESIII detector, the \(e^+e^- \to \phi\chi_{c1}(3872)\) process is searched for ...the first time. No significant signal is observed and the upper limits at the 90\% confidence level on the product of the Born cross section \(\sigma(e^+e^- \to \phi\chi_{c1}(3872))\) and the branching fraction \(\mathcal{B}\chi_{c1}(3872)\to\pi^+\pi^- J/\psi\) at 4.914 and 4.946 GeV are set to be 0.85 and 0.96 pb, respectively. These measurements provide useful information for the production of the \(\chi_{c1}(3872)\) at \(e^+e^-\) collider and deepen our understanding about the nature of this particle.
Based on \(2.7 \times 10^9~\psi(3686)\) decays collected with the BESIII detector, the radiative decay \(\psi(3686)\to\gamma2(\pi^{+}\pi^{-})\eta\) is investigated to measure properties of S- and ...P-wave charmonium states. The branching fraction of the decay \(\eta_{c}(1S) \to 2(\pi^{+}\pi^{-})\eta\), which is found to have a strong dependence on the interference pattern between \(\eta_c(1S)\) and non-\(\eta_c(1S)\) processes, is measured in both destructive and constructive interference scenarios for the first time. The mass and width of the \(\eta_{c}(1S)\) are measured to be \(M=(2984.14 \pm 0.13 \pm 0.38)\) MeV/\(c^{2}\) and \(\Gamma=(28.82 \pm 0.11 \pm 0.82)\) MeV, respectively. Clear signals for the decays of the \(\chi_{cJ}(J=0,1,2)\) and the \(\eta_{c}(2S)\) to \(2(\pi^{+}\pi^{-})\eta\) are also observed for the first time, and the corresponding branching fractions are measured. The ratio of the branching fractions between the \(\eta_{c}(2S)\) and \(\eta_{c}(1S)\) decays is significantly lower than the theoretical prediction, which might suggest different dynamics in their decays.
Abstract Effective management of hydrogen isotopes retention in plasma-facing materials (PFMs) is crucial, particularly when utilizing tritium (T) as fuel, for the success of burning plasma ...operations. Boronization, a widely employed technique for controlling fuel recycling and mitigating impurity influx from plasma-surface interactions into the core of burning plasma, significantly influences hydrogen isotopes retention in PFMs. In this study, boronization films were generated by ion cyclotron range of frequency (ICRF) discharge assisted boronization with C 2 B 10 H 12 as boron source on tungsten substrates at Experimental Advanced Superconducting Tokamak (EAST) which employing ITER-like water-cooled W monoblock PFMs and components (PFCs), followed by in-situ glow discharge (GD) cleaning for 2 h and 20 shots (180 s) edge-plasma exposure. Employing the Material and Plasma Evaluation System (MAPES), representative samples were analyzed after each process. The resultant carbon–boron films, dense and continuous, exhibited thickness up to 120 nm and were identified as amorphous in structure. It was observed that the D 2 -GD cleaning resulted in a significant isotopic exchange effect, effectively reducing the hydrogen (H) retention in the carbon–boron films. This hydrogen isotope replacement efficiency was found to be influenced by the thickness of the films. Notably, after boundary plasma exposure, samples with thicker films demonstrated an enhanced capacity to capture deuterium (D), adsorbing 10 times more D than bare tungsten (W). Our findings offer transformative insights for T recycling analysis and the plasma operation of devices like International Thermonuclear Experimental Reactor (ITER), highlighting the impact of boronization and subsequent treatments on hydrogen isotope retention behavior in PFMs.
We measure the absolute branching fractions of semileptonic \(D^+_s\) decays via the \(e^+e^-\to D_s^{*+}D_s^{*-}\) process using \(e^+e^-\) collision data corresponding to an integrated luminosity ...of \(10.64~\mathrm{fb}^{-1}\) collected by the BESIII detector at center-of-mass energies between 4.237 and 4.699 GeV. The branching fractions are \({\mathcal B}(D_s^+\to \eta e^+\nu_e)=(2.35\pm0.11_{\rm stat}\pm 0.10_{\rm syst})\%,\) \({\mathcal B}(D_s^+\to \eta^\prime e^+\nu_e)=(0.82\pm0.09_{\rm stat}\pm 0.04_{\rm syst})\%,\) \({\mathcal B}(D_s^+\to \phi e^+\nu_e)=(2.21\pm0.16_{\rm stat}\pm 0.11_{\rm syst})\%,\) \({\mathcal B}(D_s^+\to f_0(980) e^+\nu_e,f_0(980)\to\pi^+\pi^-)=(0.15\pm0.02_{\rm stat}\pm 0.01_{\rm syst})\%,\) \({\mathcal B}(D_s^+\to K^0 e^+\nu_e)=(0.24\pm0.04_{\rm stat}\pm 0.01_{\rm syst})\%,\) and \({\mathcal B}(D_s^+\to K^{*0} e^+\nu_e)=(0.19\pm0.03_{\rm stat}\pm 0.01_{\rm syst})\%.\) These results are consistent with those measured via the \(e^+e^-\to D_s^{*\pm}D_s^{\mp}\) process by BESIII and CLEO. The hadronic transition form factors \(D^+_s\to \eta e^+\nu_e\), \(D^+_s\to \eta^\prime e^+\nu_e\), and \(D^+_s\to K^0 e^+\nu_e\) at four-momentum transfer squared \(q^2\) = 0 are determined to be \(f^{\eta}_+(0) = 0.482 \pm 0.011_{\rm stat} \pm 0.009_{\rm syst}\pm0.004_{\rm input},\) \(f^{\eta^{\prime}}_+(0) = 0.562 \pm 0.031_{\rm stat} \pm 0.014_{\rm syst}\pm0.003_{\rm input},\) and \(f^{K^0}_+(0) = 0.624 \pm 0.052_{\rm stat} \pm 0.013_{\rm syst}\pm0.002_{\rm input}.\)
We perform the first amplitude analysis of \(D^+_s \to \pi^+\pi^+\pi^-\pi^0\) decays, based on data samples of electron-positron collisions recorded with the BESIII detector at center-of-mass ...energies between 4.128 and 4.226 GeV, corresponding to an integrated luminosity of 7.33~fb\(^{-1}\). We report the observation of \(D_{s}^{+} \to f_0(980)\rho(770)^{+}\) with a statistical significance greater than 10\(\sigma\) and determine the branching fractions \(\mathcal{B}(D_s^+\to\pi^+\pi^+\pi^-\pi^0|_{{\rm non}-\eta})=(2.04\pm0.08_{\rm stat.}\pm0.05_{\rm syst.})\%\) and \(\mathcal{B}(D_s^+\to\eta\pi^+)=(1.56\pm0.09_{\rm stat.}\pm0.04_{\rm syst.})\%\). Moreover, we measure the relative branching fraction between \(\phi\to\pi^+\pi^-\pi^0\) and \(\phi\to K^+K^-\) to be \(\frac{\mathcal{B}(\phi(1020) \to \pi^+\pi^-\pi^0)}{\mathcal{B}(\phi(1020) \to K^+K^-)}=0.230 \pm 0.014_{\rm stat.} \pm 0.010_{\rm syst.}\), which deviates from the world average value by more than \(4\sigma\).
Based on \((2712.4 \pm 14.3) \times 10^{6}\) \( e^{+}e^{-}\to\psi(3686)\) events collected with the BESIII detector operating at the BEPCII collider, we report the first evidence of \(\chi_{c0}\to ...\Lambda\bar \Lambda \phi\) decays and the first observation of \(\chi_{c1,2}\to \Lambda\bar \Lambda \phi\) decays, with significances of \(4.5\sigma\), \(11.3\sigma\) and \(13.0\sigma\), respectively. The decay branching fractions of \(\chi_{c0,1,2}\to \Lambda\bar \Lambda\phi\) are measured to be \(( 2.99\pm1.24\pm0.19) \times 10^{-5}\), \((6.01\pm0.90\pm0.40 )\times 10^{-5}\), and \((7.13\pm0.81\pm0.36) \times 10^{-5}\), where the first uncertainties are statistical and the second systematic. No obvious enhancement near the \(\Lambda \bar{\Lambda}\) production threshold or excited \(\Lambda\) state is found in the \(\Lambda \phi\) (or \(\bar{\Lambda}\phi\)) system.
Using data samples with an integrated luminosity of \(4.67~\mathrm{fb}^{-1}\) collected by the BESIII detector operating at the BEPCII collider, we search for the process \(e^+e^- \rightarrow \eta' ...\psi(2S)\) at center-of-mass energies from \(4.66\) to \(4.95~\mathrm{GeV}\). No significant signal is observed, and upper limits for the Born cross sections \(\sigma^B(e^+e^-\rightarrow\eta'\psi(2S))\) at the 90\% confidence level are determined.
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