123 research outputs found
Production of phi mesons at mid-rapidity in sqrt(s_NN) = 200 GeV Au+Au collisions at RHIC
We present the first results of meson production in the K^+K^- decay channel
from Au+Au collisions at sqrt(s_NN) = 200 GeV as measured at mid-rapidity by
the PHENIX detector at RHIC. Precision resonance centroid and width values are
extracted as a function of collision centrality. No significant variation from
the PDG accepted values is observed. The transverse mass spectra are fitted
with a linear exponential function for which the derived inverse slope
parameter is seen to be constant as a function of centrality. These data are
also fitted by a hydrodynamic model with the result that the freeze-out
temperature and the expansion velocity values are consistent with the values
previously derived from fitting single hadron inclusive data. As a function of
transverse momentum the collisions scaled peripheral.to.central yield ratio RCP
for the is comparable to that of pions rather than that of protons. This result
lends support to theoretical models which distinguish between baryons and
mesons instead of particle mass for explaining the anomalous proton yield.Comment: 326 authors, 24 pages text, 23 figures, 6 tables, RevTeX 4. To be
submitted to Physical Review C as a regular article. Plain text data tables
for the points plotted in figures for this and previous PHENIX publications
are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm
FOXC2 Expression is Associated with Tumor Proliferation and Invasion Potential in Oral Tongue Squamous Cell Carcinoma
Forkhead box protein C2 (FOXC2) is a gene encoding a transcription factor that controls the generation of mesodermal tissue including vascular and lymphatic tissues. FOXC2 has previously been associated with EMT and tumor angiogenesis in various cancers. Moreover, a relationship between the expression of FOXC2 and poor prognosis has been reported in various cancers. We herein examined the clinicopathological significance of FOXC2 in oral tongue squamous cell carcinoma (OTSCC) and attempted to clarify the function of FOXC2 in OTSCC cell lines in vitro. The overexpression of FOXC2 was more frequent in cancers with higher grades according to the pattern of invasion (grade 4 vs. 1?3; p < 0.05). A correlation was observed between the expression of FOXC2 and that of VEGF-A and -C (VEGF-A; p < 0.05, VEGF-C; p < 0.001). The high-FOXC2 expression group had a significantly poorer prognosis than that of the low-expression group (p < 0.001). Multivariate analysis indicated that the overexpression of FOXC2 may also be an independent prognostic factor, similar to N classification (N0 vs 1/2; p < 0.05), stage classification (stage I/II vs III/IV; p < 0.05), pattern of invasion (grade 1-3vs 4; p < 0.05), local recurrence (local recurrence (+) vs (?); p < 0.01), and the overexpression of FOXC2 (FOXC2 overexpression (?) vs.(+); p < 0.05). In the OTSCC cell line analysis, the expression of FOXC2 was also associated with proliferation and invasion potential. These results strongly suggest that the overexpression of FOXC2 may be a potent predictor of survival in OTSCC patients
The role of the ubiquitination–proteasome pathway in breast cancer: Ubiquitin mediated degradation of growth factor receptors in the pathogenesis and treatment of cancer
Aberrant activity of growth factor receptors has been implicated in the pathogenesis of a wide variety of malignancies. The negative regulation of signaling by growth factor receptors is mediated in large part by the ubiquitination, internalization, and degradation of the activated receptor. Over the past few years, considerable insight into the mechanisms that control receptor downregulation has been gained. There are also data suggesting that mutations that lead to inhibition of downregulation of growth factor receptors could play a role in the pathogenesis of cancer. Therapies directed at enhancing the degradation of growth factor receptors offer a promising approach to the treatment of malignancies
J/psi production from proton-proton collisions at sqrt(s) = 200 GeV
J/psi production has been measured in proton-proton collisions at sqrt(s)=
200 GeV over a wide rapidity and transverse momentum range by the PHENIX
experiment at RHIC. Distributions of the rapidity and transverse momentum,
along with measurements of the mean transverse momentum and total production
cross section are presented and compared to available theoretical calculations.
The total J/psi cross section is 3.99 +/- 0.61(stat) +/- 0.58(sys) +/-
0.40(abs) micro barns. The mean transverse momentum is 1.80 +/- 0.23(stat) +/-
0.16(sys) GeV/c.Comment: 326 authors, 6 pages text, 4 figures, 1 table, RevTeX 4. To be
submitted to PRL. Plain text data tables for the points plotted in figures
for this and previous PHENIX publications are (or will be) publicly available
at http://www.phenix.bnl.gov/papers.htm
Measurement of Single Electron Event Anisotropy in Au+Au Collisions at sqrt(s_NN) = 200 GeV
The transverse momentum dependence of the azimuthal anisotropy parameter v_2,
the second harmonic of the azimuthal distribution, for electrons at
mid-rapidity (|eta| < 0.35) has been measured with the PHENIX detector in Au+Au
collisions at sqrt(s_NN) = 200 GeV. The measurement was made with respect to
the reaction plane defined at high rapidities (|eta| = 3.1 -- 3.9). From the
result we have measured the v_2 of electrons from heavy flavor decay after
subtraction of the v_2 of electrons from other sources such as photon
conversions and Dalitz decay from light neutral mesons. We observe a non-zero
single electron v_2 with a 90% confidence level in the intermediate p_T region.Comment: 330 authors, 11 pages text, RevTeX4, 9 figures, 1 tables. Submitted
to Physical Review C. Plain text data tables for the points plotted in
figures for this and previous PHENIX publications are (or will be) publicly
available at http://www.phenix.bnl.gov/papers.htm
Systematic Studies of the Centrality and sqrt(s_NN) Dependence of dE_T/deta and dN_ch/deta in Heavy Ion Collisions at Mid-rapidity
The PHENIX experiment at RHIC has measured transverse energy and charged
particle multiplicity at mid-rapidity in Au+Au collisions at sqrt(s_NN) = 19.6,
130 and 200 GeV as a function of centrality. The presented results are compared
to measurements from other RHIC experiments, and experiments at lower energies.
The sqrt(s_NN) dependence of dE_T/deta and dN_ch/deta per pair of participants
is consistent with logarithmic scaling for the most central events. The
centrality dependence of dE_T/deta and dN_ch/deta is similar at all measured
incident energies. At RHIC energies the ratio of transverse energy per charged
particle was found independent of centrality and growing slowly with
sqrt(s_NN). A survey of comparisons between the data and available theoretical
models is also presented.Comment: 327 authors, 25 pages text, 19 figures, 17 tables, RevTeX 4. To be
submitted to Physical Review C as a regular article. Plain text data tables
for the points plotted in figures for this and previous PHENIX publications
are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm
Centrality Dependence of Charm Production from Single Electrons in Au+Au Collisions at sqrt(s_NN) = 200 GeV
The PHENIX experiment has measured mid-rapidity transverse momentum spectra
(0.4 < p_T < 4.0 GeV/c) of single electrons as a function of centrality in
Au+Au collisions at sqrt(s_NN) = 200 GeV. Contributions to the raw spectra from
photon conversions and Dalitz decays of light neutral mesons are measured by
introducing a thin (1.7% X_0) converter into the PHENIX acceptance and are
statistically removed. The subtracted ``non-photonic'' electron spectra are
primarily due to the semi-leptonic decays of hadrons containing heavy quarks
(charm and bottom). For all centralities, charm production is found to scale
with the nuclear overlap function, T_AA. For minimum-bias collisions the charm
cross section per binary collision is N_cc^bar/T_AA = 622 +/- 57 (stat.) +/-
160 (sys.) microbarns.Comment: 326 authors, 4 pages text, 3 figures, 1 table, RevTeX 4. To be
submitted to Physical Review Letters. Plain text data tables for the points
plotted in figures for this and previous PHENIX publications are (or will be)
publicly available at http://www.phenix.bnl.gov/papers.htm
Spontaneous Breathing in Early Acute Respiratory Distress Syndrome: Insights From the Large Observational Study to UNderstand the Global Impact of Severe Acute Respiratory FailurE Study
OBJECTIVES: To describe the characteristics and outcomes of patients with acute respiratory distress syndrome with or without spontaneous breathing and to investigate whether the effects of spontaneous breathing on outcome depend on acute respiratory distress syndrome severity. DESIGN: Planned secondary analysis of a prospective, observational, multicentre cohort study. SETTING: International sample of 459 ICUs from 50 countries. PATIENTS: Patients with acute respiratory distress syndrome and at least 2 days of invasive mechanical ventilation and available data for the mode of mechanical ventilation and respiratory rate for the 2 first days. INTERVENTIONS: Analysis of patients with and without spontaneous breathing, defined by the mode of mechanical ventilation and by actual respiratory rate compared with set respiratory rate during the first 48 hours of mechanical ventilation. MEASUREMENTS AND MAIN RESULTS: Spontaneous breathing was present in 67% of patients with mild acute respiratory distress syndrome, 58% of patients with moderate acute respiratory distress syndrome, and 46% of patients with severe acute respiratory distress syndrome. Patients with spontaneous breathing were older and had lower acute respiratory distress syndrome severity, Sequential Organ Failure Assessment scores, ICU and hospital mortality, and were less likely to be diagnosed with acute respiratory distress syndrome by clinicians. In adjusted analysis, spontaneous breathing during the first 2 days was not associated with an effect on ICU or hospital mortality (33% vs 37%; odds ratio, 1.18 [0.92-1.51]; p = 0.19 and 37% vs 41%; odds ratio, 1.18 [0.93-1.50]; p = 0.196, respectively ). Spontaneous breathing was associated with increased ventilator-free days (13 [0-22] vs 8 [0-20]; p = 0.014) and shorter duration of ICU stay (11 [6-20] vs 12 [7-22]; p = 0.04). CONCLUSIONS: Spontaneous breathing is common in patients with acute respiratory distress syndrome during the first 48 hours of mechanical ventilation. Spontaneous breathing is not associated with worse outcomes and may hasten liberation from the ventilator and from ICU. Although these results support the use of spontaneous breathing in patients with acute respiratory distress syndrome independent of acute respiratory distress syndrome severity, the use of controlled ventilation indicates a bias toward use in patients with higher disease severity. In addition, because the lack of reliable data on inspiratory effort in our study, prospective studies incorporating the magnitude of inspiratory effort and adjusting for all potential severity confounders are required
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