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Gene mutations were found in acute myeloid leukemia (AML) and their importance has been noted. To clarify the importance and stability of mutations, we examined gene mutations in paired samples at diagnosis and relapse of 34 adult AML patients. Five acquired gene mutations were detected at relapse. Of the 45 gene mutations at diagnosis, 11 of them were lost at relapse. The acquired mutations at relapse were all class I mutations as Fms-like tyrosine kinase 3 ( FLT3 ) and rat sarcoma viral oncogene homolog ( RAS) mutations. The disappeared mutations at relapse were 3 of 11 internal tandem duplications of FLT3 (FLT3- ITD) (27.3%), 3 of 3 FLT3 tyrosine kinase domain ( FLT3 -TKD) (100%), 3 of 13 Nucleophosmin 1 (23.1%) and 2 of 5 CCAAT/enhancer-binding protein-α (40%) mutations. However, epigenetics-modifying gene ( DNMT3a , TET2 and IDH1/2 ) mutations had no change between diagnosis and relapse samples, and may become minimal residual disease marker. The frequency of FLT3 -ITD at relapse in patients with DNMT3a mutation at diagnosis is significantly higher than those in patients without them ( P =0.001). Moreover, the high frequency of FLT3 -ITD at relapse is also seen in AML cases that initially present with any epigenetics-modifying gene mutations ( P <0.001). Our results indicate that epigenetics-modifying gene mutations may cause genetic instability and induce FLT3 -ITD, leading to resistance to therapy and relapse.

The measurement of an alignment between the angular momentum of a non-central collision between heavy ions and the spin of emitted particles reveals that the fluid produced in the collision is extremely vortical. Colliding ions go into a vortex When heavy ions such as gold collide in a particle collider, they form exotic states of matter that are similar to fluids. If the particles hit non-centrally, then the fluid is predicted to have vortices. However, these vortices have not yet been observed in an experiment. Here, the STAR Collaboration shows that during gold–gold collisions, spin alignment of Λ hyperons with the angular momentum of the fluid occurs. This is experimental evidence of the formation of vortices. They also show that the fluid produced in heavy-ion collisions has the highest vorticity ever observed. The results could provide general insights into how vortices form in ideal liquids. The extreme energy densities generated by ultra-relativistic collisions between heavy atomic nuclei produce a state of matter that behaves surprisingly like a fluid, with exceptionally high temperature and low viscosity 1 . Non-central collisions have angular momenta of the order of 1,000 ћ , and the resulting fluid may have a strong vortical structure 2 , 3 , 4 that must be understood to describe the fluid properly. The vortical structure is also of particular interest because the restoration of fundamental symmetries of quantum chromodynamics is expected to produce novel physical effects in the presence of strong vorticity 5 . However, no experimental indications of fluid vorticity in heavy ion collisions have yet been found. Since vorticity represents a local rotational structure of the fluid, spin–orbit coupling can lead to preferential orientation of particle spins along the direction of rotation. Here we present measurements of an alignment between the global angular momentum of a non-central collision and the spin of emitted particles (in this case the collision occurs between gold nuclei and produces Λ baryons), revealing that the fluid produced in heavy ion collisions is the most vortical system so far observed. (At high energies, this fluid is a quark–gluon plasma.) We find that Λ and hyperons show a positive polarization of the order of a few per cent, consistent with some hydrodynamic predictions 6 . (A hyperon is a particle composed of three quarks, at least one of which is a strange quark; the remainder are up and down quarks, found in protons and neutrons.) A previous measurement 7 that reported a null result, that is, zero polarization, at higher collision energies is seen to be consistent with the trend of our observations, though with larger statistical uncertainties. These data provide experimental access to the vortical structure of the nearly ideal liquid 8 created in a heavy ion collision and should prove valuable in the development of hydrodynamic models that quantitatively connect observations to the theory of the strong force.

We present the rst J/ψ and measurements in the di-muon decay channel at mid-rapidity at RHIC using the newly installed Muon Telescope Detector. In p+p collisions at s=500 Gev, inclusive J/ψ cross section can be described by CGC+NRQCD and NLO NRQCD model calculations for 0 < pT < 20 GeV/c. In Au+Au collisions at sNN=200 Gev, we observe (i) clear J/ψ suppression indicating dissociation; (ii) J/ψ RAA can be qualitatively described by transport models including dissociation and regeneration with a tension at high pT; and (iii) hint of less melting of ϒ(2S + 3S) relative to ϒ(1S) at RHIC compared to that at LHC.

At the origin of the Universe, an asymmetry between the amount of created matter and antimatter led to the matter-dominated Universe as we know it today. The origins of this asymmetry remain unknown so far. High-energy nuclear collisions create conditions similar to the Universe microseconds after the Big Bang, with comparable amounts of matter and antimatter 1 – 6 . Much of the created antimatter escapes the rapidly expanding fireball without annihilating, making such collisions an effective experimental tool to create heavy antimatter nuclear objects and to study their properties 7 – 14 , hoping to shed some light on the existing questions on the asymmetry between matter and antimatter. Here we report the observation of the antimatter hypernucleus H ¯ Λ ¯ 4 , composed of a Λ ¯ , an antiproton and two antineutrons. The discovery was made through its two-body decay after production in ultrarelativistic heavy-ion collisions by the STAR experiment at the Relativistic Heavy Ion Collider 15 , 16 . In total, 15.6 candidate H ¯ Λ ¯ 4 antimatter hypernuclei are obtained with an estimated background count of 6.4. The lifetimes of the antihypernuclei H ¯ Λ ¯ 3 and H ¯ Λ ¯ 4 are measured and compared with the lifetimes of their corresponding hypernuclei, testing the symmetry between matter and antimatter. Various production yield ratios among (anti)hypernuclei (hypernuclei and/or antihypernuclei) and (anti)nuclei (nuclei and/or antinuclei) are also measured and compared with theoretical model predictions, shedding light on their production mechanisms. An antimatter hypernucleus formed by an anti-lambda hadron, an antiproton and two antineutrons was observed through its two-body decay after production in ultrarelativistic heavy-ion collisions.

A bstract We report multi-differential measurements of strange hadron production ranging from mid- to target-rapidity in Au+Au collisions at a center-of-momentum energy per nucleon pair of s NN = 3 GeV with the STAR experiment at RHIC. K S 0 meson and Λ hyperon yields are measured via their weak decay channels. Collision centrality and rapidity dependences of the transverse momentum spectra and particle ratios are presented. Particle mass and centrality dependence of the average transverse momenta of Λ and K S 0 are compared with other strange particles, providing evidence of the development of hadronic rescattering in such collisions. The 4 π yields of each of these strange hadrons show a consistent centrality dependence. Discussions on radial flow, the strange hadron production mechanism, and properties of the medium created in such collisions are presented together with results from hadronic transport and thermal model calculations.

The pseudorapidity distribution of charged hadrons produced in Au+Au collisions at a center-of-mass energy of $\\sqrt{{\\textrm{s}}_{\\textrm{NN}}}$ = 200 GeV is measured using data collected by the sPHENIX detector. Charged hadron yields are extracted by counting cluster pairs in the inner and outer layers of the Intermediate Silicon Tracker, with corrections applied for detector acceptance, reconstruction efficiency, combinatorial pairs, and contributions from secondary decays. The measured distributions cover |η| < 1.1 across various centralities, and the average pseudorapidity density of charged hadrons at mid-rapidity is compared to predictions from Monte Carlo heavy-ion event generators. This result, featuring full azimuthal coverage at mid-rapidity, is consistent with previous experimental measurements at the Relativistic Heavy Ion Collider, thereby supporting the broader sPHENIX physics program.

The pseudorapidity distribution of charged hadrons produced in Au+Au collisions at a center-of-mass energy of$$ \\sqrt{{\\textrm{s}}_{\\textrm{NN}}} $$s NN = 200 GeV is measured using data collected by the sPHENIX detector. Charged hadron yields are extracted by counting cluster pairs in the inner and outer layers of the Intermediate Silicon Tracker, with corrections applied for detector acceptance, reconstruction efficiency, combinatorial pairs, and contributions from secondary decays. The measured distributions cover | η | < 1 . 1 across various centralities, and the average pseudorapidity density of charged hadrons at mid-rapidity is compared to predictions from Monte Carlo heavy-ion event generators. This result, featuring full azimuthal coverage at mid-rapidity, is consistent with previous experimental measurements at the Relativistic Heavy Ion Collider, thereby supporting the broader sPHENIX physics program.

The pseudorapidity distribution of charged hadrons produced in Au + Au collisions at a center-of-mass energy of √s̅_̅(̅N̅N̅)̅ = 200 GeV is measured using data collected by the sPHENIX detector. Charged hadron yields are extracted by counting cluster pairs in the inner and outer layers of the Intermediate Silicon Tracker, with corrections applied for detector acceptance, reconstruction efficiency, combinatorial pairs, and contributions from secondary decays. The measured distributions cover |η| < 1.1 across various centralities, and the average pseudorapidity density of charged hadrons at mid-rapidity is compared to predictions from Monte Carlo heavy-ion event generators. This result, featuring full azimuthal coverage at mid-rapidity, is consistent with previous experimental measurements at the Relativistic Heavy Ion Collider, thereby supporting the broader sPHENIX physics program.

The pseudorapidity distribution of charged hadrons produced in Au+Au collisions at a center-of-mass energy of $\\sqrt{{\\textrm{s}}_{\\textrm{NN}}}$ = 200 GeV is measured using data collected by the sPHENIX detector. Charged hadron yields are extracted by counting cluster pairs in the inner and outer layers of the Intermediate Silicon Tracker, with corrections applied for detector acceptance, reconstruction efficiency, combinatorial pairs, and contributions from secondary decays. The measured distributions cover |η| < 1.1 across various centralities, and the average pseudorapidity density of charged hadrons at mid-rapidity is compared to predictions from Monte Carlo heavy-ion event generators. This result, featuring full azimuthal coverage at mid-rapidity, is consistent with previous experimental measurements at the Relativistic Heavy Ion Collider, thereby supporting the broader sPHENIX physics program.

Abstract The ‘jet in cross-flow’ (JICF) phenomenon, in which a single jet issues normally into a cross-flow through a circular nozzle, is an aspect of many aerodynamic applications and is related to the effectiveness of both propulsion and control systems. In many instances, such applications involve two or more jets that may interact with each other as they develop in the downstream direction. By considering an oblique nozzle ground arrangement, the present experimental work extends the previous results that the authors have obtained for ‘twin JICF’ (TJICF) concerning two geometrically symmetric TJICF arrangements, namely tandem and side-by-side nozzle configurations. The work concentrates on the vorticity distribution and overall circulation associated with the dominant vortical structure of the TJICF, rather similar to that of the well-known contrarotating vortex pair of the single JICF.