2,472 research outputs found
Collective Flow Measurements from the PHENIX Experiment
Recent collective flow measurements including higher moment event anisotropy
from the PHENIX experiment are presented, and the particle type, beam energy
dependence and the relation with jet modification are discussed. The measured
higher order event anisotropy with event plane defined at forward rapidities
and the long range correlation with large gaps are both consistent with
initial geometrical fluctuation of the participating nuclei. In 200 GeV Au+Au
collisions, higher order event anisotropy, especially simultaneous description
of v and v, is found to give an additional constraining power on
initial geometrical condition and viscosity in the hydrodynamic calculations.
v, v and v are almost unchanged down to the lower colliding energy
at 39 GeV in Au+Au. The measured two particle correlation with subtraction of
the measured v parameters shows a significant effect on the shape and yield
in the associate particle distribution with respect to the
azimuthal direction of trigger particles. However some medium responses from
jet suppression or jet modification seems to be observed. Direct photon v
has been measured in 200 GeV Au+Au collisions. The measured v is found to
be small at high p as expected from non-suppressed direct photon
R 1, which can be understood as being dominated by prompt
photons from initial hard scattering. On the other hand, at lower p
4 GeV/c it is found to be significantly larger than zero, which is
comparable to other hadron v, where thermal photons are observed.Comment: 8 pages, 10 figures, Quark Matter 2011 proceeding
Theory of x-ray absorption by laser-dressed atoms
An ab initio theory is devised for the x-ray photoabsorption cross section of
atoms in the field of a moderately intense optical laser (800nm, 10^13 W/cm^2).
The laser dresses the core-excited atomic states, which introduces a dependence
of the cross section on the angle between the polarization vectors of the two
linearly polarized radiation sources. We use the Hartree-Fock-Slater
approximation to describe the atomic many-particle problem in conjunction with
a nonrelativistic quantum-electrodynamic approach to treat the photon-electron
interaction. The continuum wave functions of ejected electrons are treated with
a complex absorbing potential that is derived from smooth exterior complex
scaling. The solution to the two-color (x-ray plus laser) problem is discussed
in terms of a direct diagonalization of the complex symmetric matrix
representation of the Hamiltonian. Alternative treatments with time-independent
and time-dependent non-Hermitian perturbation theories are presented that
exploit the weak interaction strength between x rays and atoms. We apply the
theory to study the photoabsorption cross section of krypton atoms near the K
edge. A pronounced modification of the cross section is found in the presence
of the optical laser.Comment: 13 pages, 3 figures, 1 table, RevTeX4, corrected typoe
Properties of metastable alkaline-earth-metal atoms calculated using an accurate effective core potential
The first three electronically excited states in the alkaline-earth-metal
atoms magnesium, calcium, and strontium comprise the (nsnp) triplet P^o_J
(J=0,1,2) fine-structure manifold. All three states are metastable and are of
interest for optical atomic clocks as well as for cold-collision physics. An
efficient technique--based on a physically motivated potential that models the
presence of the ionic core--is employed to solve the Schroedinger equation for
the two-electron valence shell. In this way, radiative lifetimes, laser-induced
clock shifts, and long-range interaction parameters are calculated for
metastable Mg, Ca, and Sr.Comment: 13 pages, 9 table
Quenching and Tomography from RHIC to LHC
We compare fully perturbative and fully nonperturbative pictures of high-pT
energy loss calculations to the first results from LHC. While over-suppressed
compared to published ALICE data, parameter-free pQCD predictions based on the
WHDG energy loss model constrained to RHIC data simultaneously describe well
the preliminary CMS hadron suppression, ATLAS charged hadron v2, and ALICE D
meson suppression; we also provide for future reference WHDG predictions for B
meson RAA. However, energy loss calculations based on AdS/CFT also
qualitatively describe well the RHIC pion and non-photonic electron suppression
and LHC charged hadron suppression. We propose the double ratio of charm to
bottom quark RAA will qualitatively distinguish between these two energy loss
pictures.Comment: 4 pages, 3 figures. Proceedings for Quark Matter 201
Therapeutic limitations in tumor-specific CD8+ memory T cell engraftment
BACKGROUND: Adoptive immunotherapy with cytotoxic T lymphocytes (CTL) represents an alternative approach to treating solid tumors. Ideally, this would confer long-term protection against tumor. We previously demonstrated that in vitro-generated tumor-specific CTL from the ovalbumin (OVA)-specific OT-I T cell receptor transgenic mouse persisted long after adoptive transfer as memory T cells. When recipient mice were challenged with the OVA-expressing E.G7 thymoma, tumor growth was delayed and sometimes prevented. The reasons for therapeutic failures were not clear. METHODS: OT-I CTL were adoptively transferred to C57BL/6 mice 21 – 28 days prior to tumor challenge. At this time, the donor cells had the phenotypical and functional characteristics of memory CD8+ T cells. Recipients which developed tumor despite adoptive immunotherapy were analyzed to evaluate the reason(s) for therapeutic failure. RESULTS: Dose-response studies demonstrated that the degree of tumor protection was directly proportional to the number of OT-I CTL adoptively transferred. At a low dose of OT-I CTL, therapeutic failure was attributed to insufficient numbers of OT-I T cells that persisted in vivo, rather than mechanisms that actively suppressed or anergized the OT-I T cells. In recipients of high numbers of OT-I CTL, the E.G7 tumor that developed was shown to be resistant to fresh OT-I CTL when examined ex vivo. Furthermore, these same tumor cells no longer secreted a detectable level of OVA. In this case, resistance to immunotherapy was secondary to selection of clones of E.G7 that expressed a lower level of tumor antigen. CONCLUSIONS: Memory engraftment with tumor-specific CTL provides long-term protection against tumor. However, there are several limitations to this immunotherapeutic strategy, especially when targeting a single antigen. This study illustrates the importance of administering large numbers of effectors to engraft sufficiently efficacious immunologic memory. It also demonstrates the importance of targeting several antigens when developing vaccine strategies for cancer
UV-Spectrophotometric Determination of Telmisartan and Hydrochlorothiazide in Combined Tablet Dosage Form Using Simultaneous Equation Method
A UV spectrophotometric method was developed for the estimation of Telmisartan and Hydrochlorothiazide in Combined Tablet Dosage Form Using Simultaneous Equation Method. The drug obeyed the Beers law and shows good correlation near to r 2 = 0.999 for Telmisartan and for Hydrochlorothiazide r 2 =0.999.Absorption maxima of Telmisartan 296.8 nm and Hydrochlorothiazide 271.2 nm. Beers law was obeyed in concentration rang of 5-30 g/ml for Telmisartan and 2-12 g/ml for Hydrochlorothiazide. The method has been validated for linearity, accuracy and precision. The recovery was 99.28 % for Telmisartan and 99.26% for Hydrochlorothiazide. The developed method was found to be accurate, simple, precise, economical, and selective for simultaneous estimation of Telmisartan and Hydrochlorothiazide in tablet formulations
Analysis of Inelasticity Effect Due to Damage on Stress Distributions in Composite Laminates
A damage mechanics model characterizing damage behavior of composite materials proposed earlier by the authors is employed to analyze the damage effects on stress field near the free edge in symmetrically laminated graphite/epoxy composites of finite dimensions under umaxial tension. A quasi-three-dimensional finite element analy sis is developed for the present investigation. The results from the damaged and undam aged stress distributions of [0/90°]s, [90/0°]s, and [±45°] s laminates are compared and examined. The processes of initiation and development of damage zone in these composite laminates are also discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68869/2/10.1177_073168449301200805.pd
- …