4,458 research outputs found

    Trace initial interaction from final state observable in relativistic heavy ion collisions

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    In order to trace the initial interaction in ultra-relativistic heavy ion collision in all azimuthal directions, two azimuthal multiplicity-correlation patterns -- neighboring and fixed-to-arbitrary angular-bin correlation patterns -- are suggested. From the simulation of Au + Au collisions at 200 GeV by using the Monte Carlo models RQMD with hadron re-scattering and AMPT with and without string melting, we observe that the correlation patterns change gradually from out-of-plane preferential one to in-plane preferential one when the centrality of collision shifts from central to peripheral, meanwhile the anisotropic collective flow v_2 keeps positive in all cases. This regularity is found to be model and collision energy independent. The physics behind the two opposite trends of correlation patterns, in particular, the presence of out-of-plane correlation patterns at RHIC energy, are discussed.Comment: 5pages, 4figure

    Rapidity bin multiplicity correlations from a multi-phase transport model

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    The central-arbitrary bin and forward-backward bin multiplicity correlation patterns for Au+Au collisions at sNN\sqrt{s_{NN}} = 7.7−62.47.7-62.4 GeV are investigated within a multi-phase transport (AMPT) model. An interesting observation is that for sNN<19.6\sqrt{s_{NN}} <19.6 GeV Au+Au collisions, these two correlation patterns both have an increase with the pseudorapidity gap, while for sNN>19.6\sqrt{s_{NN}} >19.6 GeV Au+Au collisions, they decrease. We mainly discuss the influence of different evolution stages of collision system on the central-arbitrary bin correlations, such as the initial conditions, partonic scatterings, hadronization scheme and hadronic scatterings. Our results show that the central-arbitrary bin multiplicity correlations have different responses to partonic phase and hadronic phase, which can be suggested as a good probe to explore the dynamical evolution mechanism of the hot dense matter in high-energy heavy-ion collisions.Comment: 7pages, 6 figures, accepted for publication in EPJ

    Light anti-nuclei production in pp collisions at s\sqrt{s}=7 and 14 TeV

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    A dynamically constrained coalescence model based on the phase space quantization and classical limit method was proposed to investigate the production of light nuclei (anti-nuclei) in non-single diffractive (NSD) pp collisions at s\sqrt{s}=7 and 14 TeV. This calculation was based on the final hadronic state in the PYTHIA and PACIAE model simulations, the event sample consisted of 1.2×108\times 10^8 events in both simulations. The PACIAE model calculated Dˉ\bar D yield of 6.247×10−5\times 10^{-5} in NSD pp collisions at s\sqrt{s}=7 TeV is well comparing with the ALICE rough datum of 5.456×10−5\times 10^{-5}. It indicated the reliability of proposed method in some extent. The yield, transverse momentum distribution, and rapidity distribution of the Dˉ\bar D, 3Heˉ^3{\bar{He}}, and Λˉ3Hˉ_{\bar\Lambda} ^3{\bar H} in NSD pp collisions at s\sqrt{s} =7 and 14 TeV were predicted by PACIAE and PYTHIA model simulations. The yield resulted from PACIAE model simulations is larger than the one from PYTHIA model. This might reflect the role played by the parton and hadron rescatterings.Comment: 5 pages, 2 figure

    Quantum generalized Reed-Solomon codes: Unified framework for quantum MDS codes

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    We construct a new family of quantum MDS codes from classical generalized Reed-Solomon codes and derive the necessary and sufficient condition under which these quantum codes exist. We also give code bounds and show how to construct them analytically. We find that existing quantum MDS codes can be unified under these codes in the sense that when a quantum MDS code exists, then a quantum code of this type with the same parameters also exists. Thus as far as is known at present, they are the most important family of quantum MDS codes.Comment: 9 pages, no figure

    Treating oligohydramnios with extract of Salvia miltiorrhiza: A randomized control trial

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    Hong-n&amp;uuml; Chu, Mei-juan ShenAffiliated Hospital, School of Medicine, Hangzhou Normal University, 310016, Hangzhou, ChinaObjective: To determine whether purified herbal extract of Salvia miltiorrhiza can improve the amniotic fluid volume in pre-term oligohydramnios by improving uteroplacental circulation.Methods: Forty-three pregnant women with oligohydramnios received a daily intravenous dose of 30 mL of salvia extract mixed with 5% glucose 500 mL. A control group of 41 women received daily 5% glucose 500 mL only. The amniotic fluid index (AFI) was assessed at least twice a week by ultrasonographists who were blinded to the treatment. Both women and fetuses were monitored closely. The change in AFI was calculated and compared by paired t test within and between groups. The revised recommendations for improving the quality of reports of parallel group randomized trials were used.Results: After a mean of 7.2 &amp;plusmn; 2.7 days&amp;rsquo; therapy, ranging from 3 to 18 days, the AFI increased significantly from a mean of 4.9 &amp;plusmn; 2.3 cm to a mean of 7.12 &amp;plusmn; 2.36 cm, by a mean of AFI 0.18 &amp;plusmn; 0.06 cm/day (paired t = 3.62, p &amp;lt; 0.005). In the control group, the AFI increased from a mean of 5.1 &amp;plusmn; 2.4 cm to a mean of 5.5 &amp;plusmn; 3.1 cm after a mean of 6.1 &amp;plusmn; 3.3 days&amp;rsquo; treatment, ranging from 4 to 15 days. The effect of salvia treatment on AFI in the salvia group was significantly greater than in the control group (p &amp;lt; 0.001). No side effects were observed in treated patients.Conclusion: Salvia miltiorrhiza is an effective Chinese medicine for the treatment of oligohydramnios.Keywords: Salvia miltiorrhiza, therapy, oligohydramnios, amniotic fluid inde

    Pancreaticoduodenectomy in a patient with previous left ventricular assist device: a case report with specific emphasis on peri-operative logistics.

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    To the best of our knowledge this is the first case of this nature described in the literature. Sharing the authors experience with this case, particularly the technical challenges and post-operative management may aid other physicians facing similar scenarios. In this report, we describe a pancreaticoduodenectomy for pancreatic adenocarcinoma in a patient with a previous left ventricular assist device (LVAD). A multidisciplinary approach, particularly close involvement of the advanced heart failure, mechanical heart and pancreas surgery teams was key to the success of this case. Major abdominal surgery in the setting of previous LVAD should be considered carefully, however, the LVAD should not be generalized as an absolute contraindication

    Genetically engineered pre-microRNA-34a prodrug suppresses orthotopic osteosarcoma xenograft tumor growth via the induction of apoptosis and cell cycle arrest.

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    Osteosarcoma (OS) is the most common primary malignant bone tumor in children, and microRNA-34a (miR-34a) replacement therapy represents a new treatment strategy. This study was to define the effectiveness and safety profiles of a novel bioengineered miR-34a prodrug in orthotopic OS xenograft tumor mouse model. Highly purified pre-miR-34a prodrug significantly inhibited the proliferation of human 143B and MG-63 cells in a dose dependent manner and to much greater degrees than controls, which was attributed to induction of apoptosis and G2 cell cycle arrest. Inhibition of OS cell growth and invasion were associated with release of high levels of mature miR-34a from pre-miR-34a prodrug and consequently reduction of protein levels of many miR-34a target genes including SIRT1, BCL2, c-MET, and CDK6. Furthermore, intravenous administration of in vivo-jetPEI formulated miR-34a prodrug significantly reduced OS tumor growth in orthotopic xenograft mouse models. In addition, mouse blood chemistry profiles indicated that therapeutic doses of bioengineered miR-34a prodrug were well tolerated in these animals. The results demonstrated that bioengineered miR-34a prodrug was effective to control OS tumor growth which involved the induction of apoptosis and cell cycle arrest, supporting the development of bioengineered RNAs as a novel class of large molecule therapeutic agents
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