The Effect of Hadronic Scatterings on the Measurement of Vector Meson Spin Alignments in Heavy-Ion Collisions

Spin alignments of vector mesons and hyperons in relativistic heavy-ion collisions have been proposed as signals of the global polarization. The STAR experiment first observed the $\rm \Lambda$ polarization. Recently, the ALICE collaboration measured the transverse momentum ($p_T$) and the collision centrality dependence of $K^*$ and $\phi$ spin alignments in Pb-Pb collisions at $\rm \sqrt{s_{NN}}$ = 2.76 TeV. A large signal is observed in the low $p_T$ region of mid-central collisions for $K^*$ while the signal is much smaller for $\phi$, and these have not been understood yet. Since vector mesons have different lifetimes and their decay products have different scattering cross sections, they suffer from different hadronic effects. In this paper, we study the effect of hadronic interactions on the spin alignment of $K^*$, $\phi$ and $\rho$ mesons in relativistic heavy-ion collisions with a multi-phase transport model. We find that hadronic scatterings lead to a deviation of the observed spin alignment matrix element $\rho_{00}$ away from the true value for $\rho$ and $K^*$ mesons (with a bigger effect on $\rho$) while the effect is negligible for the $\phi$ meson. The effect depends on the kinematic acceptance: the observed $\rho_{00}$ value is lower than the true value when the pseudorapidity ($\eta$) coverage is small while there is little effect when the $\eta$ coverage is big. Our study thus provides valuable information to understand the vector meson spin alignment signals observed in the experiments.Comment: 8 pages, 7 figures, submit to Chin. Phys.

A Meta-analysis of Major Complications between Traditional Pacemakers and Leadless Pacemakers

Objectives: We aim to compare the major complications between leadless pacemakers and traditional pacemakers. Background: Leadless pacemakers, which are increasingly used in clinical practice, have several advantages compared with traditional pacemakers in avoiding pocket- and lead-related complications. However, the clinical effect of leadless pacemakers remains controversial. Methods: PubMed, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), the CNKI database, and the Wanfang database were searched from July 2013 to December 2019. Studies comparing leadless pacemakers and traditional pacemakers were included. The primary end point was major complications. The secondary end points were cardiac perforation/pericardial effusion, device revision or extraction, loss of device function, and death. Results: Six studies fulfilled the inclusion criteria. Only four of the six studies reported data on major complications. Leadless pacemakers were associated with a lower incidence of major complications (risk ratio 0.33, 95% confidence interval 0.25–0.44, P<0.00001, I 2 =49%). We extracted data on cardiac perforation/pericardial effusion, device revision or extraction, loss of device function, and death from six studies. Our meta-analysis showed that leadless pacemakers have a higher risk of cardiac perforation or pericardial effusion (risk ratio 4.28, 95% confidence interval 1.66–11.08, P=0.003, I 2 =0%). No statistically significant differences were found for mortality, device revision or extraction, and loss of device function. Conclusion: Compared with traditional pacemakers, leadless pacemakers have a significantly decreased risk of major complications, but have a higher risk of cardiac perforation or pericardial effusion

Considerations on measuring spin-spin correlation of hyeprons in heavy-ion experiments

The significant global spin alignment observed for $\phi$ mesons in heavy-ion collisions has sparked intense discussions about its origin and implications. One explanation suggests that fluctuations in the strong force field may introduce strong spin correlations between strange ($s$) and anti-strange ($\bar{s}$) quarks, leading to the global spin alignment of $\phi$ mesons. Extending this line of research, the theoretical community has proposed studying the spin correlation between $\Lambda$ and $\bar{\Lambda}$ hyperons. In this paper, we construct experimental observables and make connections between them and the theoretical proposed quantities

The effect of hadronic scatterings on the measurement of vector meson spin alignments in heavy-ion collisions *

Abstract Spin alignments of vector mesons and hyperons in relativistic heavy-ion collisions have been proposed as signals of global polarization. The STAR experiment first observed the polarization. Recently, the ALICE collaboration measured the transverse momentum ( ) and the collision centrality dependence of , and spin alignments during Pb-Pb collisions at = 2.76 TeV. A large signal is observed in the low region of mid-central collisions for , while the signal is much smaller for , and these have not been understood yet. Since vector mesons have different lifetimes and their decay products have different scattering cross sections, they suffer from different hadronic effects. In this paper, we study the effect of hadronic interactions on the spin alignment of , , and mesons in relativistic heavy-ion collisions with a multi-phase transport model. We find that hadronic scatterings lead to a deviation of the observed spin alignment matrix element away from the true value for and mesons (with a bigger effect on ) while the effect is negligible for the meson. The effect depends on the kinematic acceptance: the observed value is lower than the true value when the pseudorapidity ( ) coverage is small, while there is little effect when the coverage is large. Hence, this study provides valuable information to understand the vector meson spin alignment signals observed during the experiments. </jats:p

The Role of NLRP3 Inflammasome Activation Pathway of Hepatic Macrophages in Liver Ischemia–Reperfusion Injury

Ischemia-reperfusion injury (IRI) is considered an inherent component involved in liver transplantation, which induce early organ dysfunction and failure. And the accumulating evidences indicate that the activation of host innate immune system, especially hepatic macrophages, play a pivotal role in the progression of LIRI. Inflammasomes is a kind of intracellular multimolecular complexes that actively participate in the innate immune responses and proinflammatory signaling pathways. Among them, NLRP3 inflammasome is the best characterized and correspond to regulate caspase-1 activation and the secretion of proinflammatory cytokines in response to various pathogen-derived as well as danger-associated signals. Additionally, NLRP3 is highly expressed in hepatic macrophages, and the assembly of NLRP3 inflammasome could lead to LIRI, which makes it a promising therapeutic target. However, detailed mechanisms about NLRP3 inflammasome involving in the hepatic macrophages-related LIRI is rarely summarized. Here, we review the potential role of the NLRP3 inflammasome pathway of hepatic macrophages in LIRI, with highlights on currently available therapeutic options.</jats:p