ABSTRACT
The first (v_{1}^{fluc}), second (v_{2}), and third (v_{3}) harmonic coefficients of the azimuthal particle distribution at midrapidity are extracted for charged hadrons and studied as a function of transverse momentum (p_{T}) and mean charged particle multiplicity density ⟨N_{ch}⟩ in U+U (sqrt[s_{NN}]=193 GeV), Au+Au, Cu+Au, Cu+Cu, d+Au, and p+Au collisions at sqrt[s_{NN}]=200 GeV with the STAR detector. For the same ⟨N_{ch}⟩, the v_{1}^{fluc} and v_{3} coefficients are observed to be independent of the collision system, while v_{2} exhibits such a scaling only when normalized by the initial-state eccentricity (ĆĀµ_{2}). The data also show that ln(v_{2}/ĆĀµ_{2}) scales linearly with ⟨N_{ch}⟩^{-1/3}. These measurements provide insight into initial-geometry fluctuations and the role of viscous hydrodynamic attenuation on v_{n} from small to large collision systems.
ABSTRACT
The Λ (Λ[over ĀÆ]) hyperon polarization along the beam direction has been measured in Au+Au collisions at sqrt[s_{NN}]=200 GeV, for the first time in heavy-ion collisions. The polarization dependence on the hyperons' emission angle relative to the elliptic flow plane exhibits a second harmonic sine modulation, indicating a quadrupole pattern of the vorticity component along the beam direction, expected due to elliptic flow. The polarization is found to increase in more peripheral collisions, and shows no strong transverse momentum (p_{T}) dependence at p_{T} greater than 1 GeV/c. The magnitude of the signal is about 5 times smaller than those predicted by hydrodynamic and multiphase transport models; the observed phase of the emission angle dependence is also opposite to these model predictions. In contrast, the kinematic vorticity calculations in the blast-wave model tuned to reproduce particle spectra, elliptic flow, and the azimuthal dependence of the Gaussian source radii measured with the Hanbury Brown-Twiss intensity interferometry technique reproduce well the modulation phase measured in the data and capture the centrality and transverse momentum dependence of the polarization signal.
ABSTRACT
We report on the first measurements of J/ψ production at very low transverse momentum (p_{T}<0.2 GeV/c) in hadronic Au+Au collisions at sqrt[s_{NN}]=200 GeV and U+U collisions at sqrt[s_{NN}]=193 GeV. Remarkably, the inferred nuclear modification factor of J/ψ at midrapidity in Au+Au (U+U) collisions reaches about 24 (52) for p_{T}<0.05 GeV/c in the 60%-80% collision centrality class. This noteworthy enhancement cannot be explained by hadronic production accompanied by cold and hot medium effects. In addition, the dN/dt distribution of J/ψ for the very low p_{T} range is presented for the first time. The distribution is consistent with that expected from the Au nucleus and shows a hint of interference. Comparison of the measurements to theoretical calculations of coherent production shows that the excess yield can be described reasonably well and reveals a partial disruption of coherent production in semicentral collisions, perhaps due to the violent hadronic interactions. Incorporating theoretical calculations, the results strongly suggest that the dramatic enhancement of J/ψ yield observed at extremely low p_{T} originates from coherent photon-nucleus interactions. In particular, coherently produced J/ψ's in violent hadronic collisions may provide a novel probe of the quark-gluon plasma.
ABSTRACT
We report the first measurement of rapidity-odd directed flow (v_{1}) for D^{0} and D^{0}[over ĀÆ] mesons at midrapidity (|y|<0.8) in Au+Au collisions at sqrt[s_{NN}]=200 GeV using the STAR detector at the Relativistic Heavy Ion Collider. In 10-80% Au+Au collisions, the slope of the v_{1} rapidity dependence (dv_{1}/dy), averaged over D^{0} and D^{0}[over ĀÆ] mesons, is -0.080Ā±0.017(stat)Ā±0.016(syst) for transverse momentum p_{T} above 1.5 GeV/c. The absolute value of D^{0} meson dv_{1}/dy is about 25 times larger than that for charged kaons, with 3.4σ significance. These data give a unique insight into the initial tilt of the produced matter, and offer constraints on the geometric and transport parameters of the hot QCD medium created in relativistic heavy-ion collisions.
ABSTRACT
Rapidity-odd directed-flow measurements at midrapidity are presented for Λ, Λ[over ĀÆ], K^{Ā±}, K_{s}^{0}, and ĆĀ at sqrt[s_{NN}]=7.7, 11.5, 14.5, 19.6, 27, 39, 62.4, and 200Ā GeV in Au+Au collisions recorded by the Solenoidal Tracker detector at the Relativistic Heavy Ion Collider. These measurements greatly expand the scope of data available to constrain models with differing prescriptions for the equation of state of quantum chromodynamics. Results show good sensitivity for testing a picture where flow is assumed to be imposed before hadron formation and the observed particles are assumed to form via coalescence of constituent quarks. The pattern of departure from a coalescence-inspired sum rule can be a valuable new tool for probing the collision dynamics.
ABSTRACT
We report measurements of the nuclear modification factor R_{CP} for charged hadrons as well as identified π^{+(-)}, K^{+(-)}, and p(p[over ĀÆ]) for Au+Au collision energies of sqrt[s_{NN}]=7.7, 11.5, 14.5, 19.6, 27, 39, and 62.4Ā GeV. We observe a clear high-p_{T} net suppression in central collisions at 62.4Ā GeV for charged hadrons which evolves smoothly to a large net enhancement at lower energies. This trend is driven by the evolution of the pion spectra but is also very similar for the kaon spectra. While the magnitude of the proton R_{CP} at high p_{T} does depend on the collision energy, neither the proton nor the antiproton R_{CP} at high p_{T} exhibit net suppression at any energy. A study of how the binary collision-scaled high-p_{T} yield evolves with centrality reveals a nonmonotonic shape that is consistent with the idea that jet quenching is increasing faster than the combined phenomena that lead to enhancement.
ABSTRACT
We report first measurements of e^{+}e^{-} pair production in the mass region 0.4
ABSTRACT
We report the first measurement of the elliptic anisotropy (v_{2}) of the charm meson D^{0} at midrapidity (|y|<1) in Au+Au collisions at sqrt[s_{NN}]=200 GeV. The measurement was conducted by the STAR experiment at RHIC utilizing a new high-resolution silicon tracker. The measured D^{0} v_{2} in 0%-80% centrality Au+Au collisions can be described by a viscous hydrodynamic calculation for a transverse momentum (p_{T}) of less than 4 GeV/c. The D^{0} v_{2} as a function of transverse kinetic energy (m_{T}-m_{0}, where m_{T}=sqrt[p_{T}^{2}+m_{0}^{2}]) is consistent with that of light mesons in 10%-40% centrality Au+Au collisions. These results suggest that charm quarks have achieved local thermal equilibrium with the medium created in such collisions. Several theoretical models, with the temperature-dependent, dimensionless charm spatial diffusion coefficient (2πTD_{s}) in the range of Ć¢ĀĀ¼2-12, are able to simultaneously reproduce our D^{0} v_{2} result and our previously published results for the D^{0} nuclear modification factor.
ABSTRACT
We present the first measurement of charge-dependent directed flow in Cu+Au collisions at sqrt[s_{NN}]=200 GeV. The results are presented as a function of the particle transverse momentum and pseudorapidity for different centralities. A finite difference between the directed flow of positive and negative charged particles is observed that qualitatively agrees with the expectations from the effects of the initial strong electric field between two colliding ions with different nuclear charges. The measured difference in directed flow is much smaller than that obtained from the parton-hadron-string-dynamics model, which suggests that most of the electric charges, i.e., quarks and antiquarks, have not yet been created during the lifetime of the strong electric field, which is of the order of, or less than, 1 fm/c.
ABSTRACT
We report the first dijet transverse momentum asymmetry measurements from Au+Au and pp collisions at RHIC. The two highest-energy back-to-back jets reconstructed from fragments with transverse momenta above 2 GeV/c display a significantly higher momentum imbalance in heavy-ion collisions than in the pp reference. When reexamined with correlated soft particles included, we observe that these dijets then exhibit a unique new feature-momentum balance is restored to that observed in pp for a jet resolution parameter of R=0.4, while rebalancing is not attained with a smaller value of R=0.2.
ABSTRACT
A 59-year-old woman with ulcerative colitis developed red eyes, pleural effusion, eosinophilia and urinary abnormalities after restarting of sulphasalazine treatment. Light microscopy of a kidney biopsy revealed segmental necrotizing glomerulonephritis without deposition of immunoglobulin or complement. Proteinase 3-antineutrophil cytoplasmic antibody (PR3-ANCA) titer was elevated at 183 ELISA units (EU) in sera (normal range less than 10 EU), myeloperoxidase-ANCA was negative. PR3-ANCA titer was 250 and 1,070 EU in pleural effusions on right and left side, respectively. Although cessation of sulphasalazine treatment resulted in improvements in fever, red eyes, chest pain, titer of C-reactive protein and volume of the pleural effusions, we initiated steroid therapy, because PR3-ANCA titer rose to 320 EU, eosinophil count increased to 1,100 cells/microl, and the pleural effusion remained. One month after steroid therapy, the pleural effusion disappeared, and PR3-ANCA titer normalized 3 months later. This case suggests that sulphasalazine can induce PR3-ANCA-positive necrotizing glomerulonephritis.
Subject(s)
Antibodies, Antineutrophil Cytoplasmic/metabolism , Gastrointestinal Agents/adverse effects , Glomerulosclerosis, Focal Segmental/chemically induced , Kidney Cortex Necrosis/chemically induced , Myeloblastin/metabolism , Sulfasalazine/adverse effects , Colitis, Ulcerative/drug therapy , Colitis, Ulcerative/pathology , Female , Glomerulosclerosis, Focal Segmental/metabolism , Glomerulosclerosis, Focal Segmental/pathology , Humans , Kidney Cortex Necrosis/metabolism , Kidney Cortex Necrosis/pathology , Middle AgedABSTRACT
It has been postulated that there exists a neuronal mechanism that generates respiratory rhythm and modulates respiratory output pattern in the high cervical spinal cord. Recently, we have found a novel respiratory neuron group in the ventral portion of the high cervical spinal cord, and named it the high cervical spinal cord respiratory group (HCRG). In the present study, we analyzed the detailed anatomical architecture of the HCRG region by double immunostaining of the region using a neuron-specific marker (NeuN) and a marker for motoneurons (ChAT) in the neonatal rat. We found a large number of small NeuN-positive cells without ChAT-immunoreactivity, which were considered interneurons. We also found two and three clusters of motoneurons in the ventral portion of the ventral horn at C1 and C2 levels, respectively. Next, we examined responses of HCRG neurons to respiratory and metabolic acidosis in vitro by voltage-imaging together with cross correlation techniques, i.e., by correlation coefficient imaging, in order to understand the functional role of HCRG neurons. Both respiratory and metabolic acidosis caused the same pattern of changes in their spatiotemporal activation profiles, and the respiratory-related area was enlarged in the HCRG region. After acidosis was introduced, preinspiratory phase-dominant activity was recruited in a number of pixels, and more remarkably inspiratory phase-dominant activity was recruited in a large number of pixels. We suggest that the HCRG composes a local respiratory neuronal network consisting of interneurons and motoneurons and plays an important role in respiratory augmentation in response to acidosis.
Subject(s)
Acidosis, Respiratory/physiopathology , Cervix Uteri , Neurons/metabolism , Respiration , Spinal Cord/cytology , Animals , Animals, Newborn , Choline O-Acetyltransferase/metabolism , DNA-Binding Proteins , Female , Mice , Nerve Tissue Proteins/metabolism , Nuclear Proteins/metabolism , Rats , Staining and LabelingABSTRACT
Using a voltage-imaging technique, we analyzed the acute effect of ischemia, hypoxia and hypoglycemia on the neuronal network function of the rat spinal cord. Ischemic, hypoxic, or hypoglycemic stress was loaded to spinal cord slices with an oxygen- and glucose-free, oxygen-free, or glucose-free mock cerebrospinal fluid, respectively. Depolarizing signals in the dorsal horn, induced by dorsal root stimulation, consisted of fast (pre-synaptic) and slow (post-synaptic) components. The slow component was attenuated much more than the fast component under an ischemic condition (P<0.0002). Post-synaptic neuronal activities in lamina III-IV were suppressed earlier than those in lamina I-II. The nerve fiber was relatively resistant to ischemia. As long as the fast component was preserved in the dorsal horn, the suppression of the fast and slow components was reversible. There was a significant difference (P<0.05) in the recovered slow component sizes between the group in which the fast component was suppressed by more than 20% by ischemia and the group in which the suppression was less than 20%. Further prolonged stress irreversibly eliminated most of the slow component, and attenuated the fast component (to 59+/-8%) accompanied by cellular damage in histology. Suppression of neural activity by hypoxic or hypoglycemic stress was less prominent than that by ischemia. Prolonged ischemic stress suddenly and irreversibly eliminated depolarizing signals in the ventral horn accompanied by morphological damage of motoneurons. Immunohistochemical staining was negative for apoptosis. We have, for the first time, analyzed the processes of spinal cord disturbance induced by ischemia, hypoxia and hypoglycemia at the neuronal network level by directly observing the regional neuronal network activities within the spinal cord. We conclude that synaptic transmission in the dorsal horn, especially in deep regions, is vulnerable and first affected by these stresses. Severe ischemic stress induces irreversible dysfunction of neurons accompanied by eventual cell death in both dorsal and ventral horns.
Subject(s)
Ischemia/physiopathology , Nerve Net/blood supply , Nerve Net/physiology , Spinal Cord/blood supply , Spinal Cord/physiology , Animals , Female , In Vitro Techniques , Male , Optics and Photonics , Rats , Rats, WistarABSTRACT
A ligand-based model is reported that predicts the Ki values for cytochrome P450 2C9 (CYP2C9) inhibitors. This CoMFA model was used to predict the affinity of 14 structurally diverse compounds not in the training set and appears to be robust. The mean error of the predictions is 6 microM. The experimentally measured Ki values of the 14 compounds range from 0.1 to 48 microM. Leave-one-out cross-validated partial least-squares gives a q2 value of between 0.6 and 0.8 for the various models which indicates internal consistency. Random assignment of biological data to structure leads to negative q2 values. These models are useful in that they establish a pharmacophore for binding to CYP2C9 that can be tested with site-directed mutagenesis. These models can also be used to screen for potential drug interactions and to design compounds that will not bind to this enzyme with high affinity.
Subject(s)
Aryl Hydrocarbon Hydroxylases , Cytochrome P-450 Enzyme System/chemistry , Enzyme Inhibitors/chemistry , Steroid 16-alpha-Hydroxylase , Steroid Hydroxylases/chemistry , Binding Sites , Cytochrome P-450 Enzyme System/metabolism , Drug Interactions , Ligands , Models, Biological , Models, Molecular , Protein Binding , Reproducibility of Results , Steroid Hydroxylases/metabolism , Structure-Activity Relationship , Sulfaphenazole/chemistry , Sulfaphenazole/metabolism , Sulfonamides/chemistry , Sulfonamides/metabolism , Warfarin/chemistry , Warfarin/metabolismABSTRACT
The membranes from 42 eyes with PDR and 8 eyes with PVR were removed during vitreous surgery. In 12 of those with PDR and 3 of the cases with PVR, the reproliferated membranes formed beneath silicone oil (SO) were removed and were histologically and immunohistochemically examined, using morphometrical quantitative analysis. In each case, area coefficient, fibrous content and the number of new vessels, and thick basement membranes, increased wall cells and multilayer basement membranes of new vessels were studied. In both PDR and PVR, the number of cells per unit area tended to be increased with the period of time after SO was injected, while the percentage of fibrous components did not change. The Percentage of occurrence of each type of new vessels was almost the same in both primary and reproliferative PDR membranes. In the primary proliferative PDR membranes, endothelial cell proliferation was found predominantly, while glial hyperplasia was predominant in the primary proliferated PVR membranes and the reproliferated membranes under SO of PDR and PVR.
Subject(s)
Diabetic Retinopathy/pathology , Vitreous Body , Basement Membrane/ultrastructure , Cell Count , Cell Division , Eye Diseases/pathology , Humans , Retinal Neovascularization/pathologyABSTRACT
CS-1170 was administered in 6 cases of infections in the pediatric field and the clinical response was excellent in 3, fair in 1, poor in 1 and unknown in one. Cases of acute purulent osteomyelitis which was cured by the present drug were described in detail. Each case is summarized Table 1.
Subject(s)
Bacterial Infections/drug therapy , Cephalosporins/therapeutic use , Cephamycins/therapeutic use , Acute Disease , Age Factors , Cephamycins/administration & dosage , Child , Child, Preschool , Drug Evaluation , Female , Humans , Male , Osteomyelitis/drug therapyABSTRACT
Cefteram pivoxil (CFTM-PI), a newly developed oral cephem antibiotic was administered to treat 16 children with various infections. The results were summarized as follows. 1. The clinical responses were "excellent" in 7, "good" in 5, "fair" in 3 and "poor" in 1, with 75.0% efficacy rate. 2. No side effects and no abnormal laboratory findings were observed.
Subject(s)
Bacterial Infections/drug therapy , Cefmenoxime/analogs & derivatives , Cefmenoxime/administration & dosage , Cefmenoxime/therapeutic use , Child , Child, Preschool , Drug Evaluation , Female , Humans , Infant , MaleABSTRACT
T-1982 (cefbuperazone) is a newly developed cephamycin. Clinical studies on this drug were carried out and the results were as follows: Eighteen patients (pneumonia 13, purulent tonsillitis 1, acute bronchitis 1, cellulitis 1, urinary tract infection 2) were treated intravenously with daily 27.4-100.2 mg/kg of T-1982 in 3-4 divided dose for 3-6.7 days. The overall efficacy rate was 94.4%. No adverse reactions were observed. Abnormal laboratory data noted were liver dysfunction in 1 case (4.8%), eosinophilia in 2 cases (9.5%), and anemia in 1 case (4.8%).
Subject(s)
Anti-Bacterial Agents/therapeutic use , Cephalosporins/therapeutic use , Cephamycins/therapeutic use , Respiratory Tract Infections/drug therapy , Child, Preschool , Female , Humans , Infant , Injections, Intravenous , Male , Pneumonia/drug therapyABSTRACT
Cefuroxime, a new synthetic cephalosporin, was administered to 10 pediatric patients (6 with respiratory tract infection, 2 with urinary tract infection, 1 with sepsis of E. coli and 1 with enterocolitis). The clinical result was good and excellent in all the 10 cases. No side effect was observed in any of them.