Cold nuclear matter effects on J/ψ yields as a function of rapidity and nuclear geometry in d+A collisions at sqrt[s(NN)]=200 GeV

We present measurements of J/ψ yields in d+Au collisions at sqrt[s(NN)]=200  GeV recorded by the PHENIX experiment and compare them with yields in p+p collisions at the same energy per nucleon-nucleon collision. The measurements cover a large kinematic range in J/ψ rapidity (-2.2<y<2.4) with high statistical precision and are compared with two theoretical models: one with nuclear shadowing combined with final state breakup and one with coherent gluon saturation effects. In order to remove model dependent systematic uncertainties we also compare the data to a simple geometric model. The forward rapidity data are inconsistent with nuclear modifications that are linear or exponential in the density weighted longitudinal thickness, such as those from the final state breakup of the bound state.

Abstract P2-06-13: Pathway Profiling of Signal Transduction Proteins in Paired Tumor and Adjacent Normal Tissues Obtained from Breast Cancer Patients

Background: Targeted therapeutic strategies are currently limited to patients with hormone receptors and/or HER2 positive disease in breast cancer (BCA) treatment. However, patients often develop resistance to these therapies. The ability to functionally profile a whole spectrum of pathway proteins (and their variants) in tumor may provide valuable information about the potential mechanism for drug resistance and evidence for rational selection of suitable targeted therapies. Here we report a comprehensive profile of HER1, HER2, p95HER2, HER3, cMET, IGF1R, PI3K, Shc, AKT and other signal transduction pathway proteins in BCA tissues and their matched adjacent normal tissues (ANTs). Methods: A multiplexed Collaborative Proximity ImmunoAssay (COPIA), antibody-microarray platform requiring co-localization of 2 detector antibodies on captured biomarker proteins has been used for comprehensive pathway analysis. Channeling events between 2 detector enzymes (glucose oxidase & horse radish peroxidase) in proximity enabled the profiling of the target biomarkers with extreme sensitivity and specificity, and a direct comparison to electrochemiluminescence based immunoassay platform (MSD) was performed for pathway proteins in tumor vs. ANTs for their expression and activation in samples collected from 20 BCA patients. Results: Three dilutions of lysate (10ug, 1ug, 0.1ug) were analyzed for quantitative differential pathway modulation for COPIA.

- Substantially higher cytokeratin (CK) levels were found in 16/20 tumor samples when compared to paired-ANT; 3/20 samples showed high levels of CK in ANTs. Substantial levels of HER3 and IGF1R expression was detected in 9 and 5 tumor samples respectively.

- Over-expression of HER2 with high degree of activation was found in 2 patients. In one of the HER2-overexpressing patients, HER3 was also highly expressed and moderately phosphorylated. Co-expression of cMET and IGF1R was evident as well.

- A significant degree of HER2 phosphorylation was found in many patients with low level HER2 expression; this may be due to co-expression of high level of HER3 and other RTKs with trans-activational potential. Evidence of activated PI3K complex will be reported.

- In direct comparison to MSD, COPIA detected activated pathway proteins in samples that were not detectable with MSD. MSD was sensitive enough to detect the very extreme cases. COPIA appeared to be a more desirable method for detection of protein expression and activation for samples with limited availability. The distinct pathway modulation in each patient (detected by COPIA) will be reported.

Discussion: COPIA was used to detect the differential expression and phosphorylation of HER2, other RTKs and pathway proteins in 20 paired tumor and matched ANTs. As this platform requires magnitudes lower amounts of specimen, it can be used to profile tumors at different metastatic sites and could provide comprehensive metastatic profiles. The comprehensive functional pathway profiling of tumor specimen may provide insightful information for potential drug-resistant mechanisms and may guide appropriate selection of targeted drug-combinations or drug-sequencing.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-06-13.

Azimuthal anisotropy of π⁰ production in Au+Au collisions at sqrt((s)NN)=200 GeV: path-length dependence of jet quenching and the role of initial geometry

We have measured the azimuthal anisotropy of π⁰ production for 1<p(T)<18  GeV/c for Au+Au collisions at sqrt((s)NN)=200  GeV. The observed anisotropy shows a gradual decrease for 3≲p(T)≲7-10  GeV/c, but remains positive beyond 10  GeV/c. The magnitude of this anisotropy is underpredicted, up to at least ∼10  GeV/c, by current perturbative QCD (PQCD) energy-loss model calculations. An estimate of the increase in anisotropy expected from initial-geometry modification due to gluon saturation effects and fluctuations is insufficient to account for this discrepancy. Calculations that implement a path-length dependence steeper than what is implied by current PQCD energy-loss models show reasonable agreement with the data.

Rare-earth ions doped heavy metal germanium tellurite glasses for fiber lighting in minimally invasive surgery

In Er(3+)/Yb(3+) codoped Na(2)O-ZnO-PbO-GeO(2)-TeO(2) (NZPGT) glass fiber, a clear and compact green upconversion amplified spontaneous emission (ASE) trace is observed, and the NZPGT glasses are proved to be a desirable candidate in fabricating low-phonon energy fiber. Intense green upconversion luminescence of Er(3+), balanced green and red upconversion emissions of Ho(3+), and dominant three-photon blue upconversion fluorescence of Tm(3+) have been represented. By varying the excitation power of 974 nm wavelength laser diode, a series of green and white fluorescences have been achieved in Tm(3+)/Er(3+)/Yb(3+) and Tm(3+)/Ho(3+)/Yb(3+) triply doped glass systems, respectively. These results reveal that high-intensity blue, green, and white upconversion ASE fluorescences, which can be adopted for lighting in minimally invasive photodynamic therapy and minimally invasive surgery, are reasonable to be expected in rare-earth doped NZPGT glass fibers.

Elliptic and hexadecapole flow of charged hadrons in Au+Au collisions at sq.rt(s(NN))=200 GeV

Differential measurements of the elliptic (v(2)) and hexadecapole (v(4)) Fourier flow coefficients are reported for charged hadrons as a function of transverse momentum (p(T)) and collision centrality or number of participant nucleons (N(part)) for Au+Au collisions at sq.rt(s(NN))=200  GeV. The v(2,4) measurements at pseudorapidity |η|≤0.35, obtained with four separate reaction-plane detectors positioned in the range 1.0<|η|<3.9, show good agreement, indicating the absence of significant Δη-dependent nonflow correlations. Sizable values for v(4)(p(T)) are observed with a ratio v(4)(p(T),N(part))/v(2)(2)(p(T),N(part))≈0.8 for 50≲N(part)≲200, which is compatible with the combined effects of a finite viscosity and initial eccentricity fluctuations. For N(part)≳200 this ratio increases up to 1.7 in the most central collisions.

Transition in yield and azimuthal shape modification in dihadron correlations in relativistic heavy ion collisions

Hard-scattered parton probes produced in collisions of large nuclei indicate large partonic energy loss, possibly with collective produced-medium response to the lost energy. We present measurements of π^{0} trigger particles at transverse momenta p{T}{t}=4-12  GeV/c and associated charged hadrons (p{T}{a}=0.5-7  GeV/c) vs relative azimuthal angle Δϕ in Au+Au and p+p collisions at sqrt[s{NN}]=200  GeV. The Au+Au distribution at low p{T}{a}, whose shape has been interpreted as a medium effect, is modified for p{T}{t}<7  GeV/c. At higher p{T}{t}, the data are consistent with unmodified or very weakly modified shapes, even for the lowest measured p{T}{a}, which quantitatively challenges some medium response models. The associated yield of hadrons opposing the trigger particle in Au+Au relative to p+p (I{AA}) is suppressed at high p{T} (I{AA}≈0.35-0.5), but less than for inclusive suppression (R{AA}≈0.2).

Enhanced production of direct photons in Au + Au collisions at square root(S(NN)) = 200 GeV and implications for the initial temperature

The production of e+ e- pairs for m(e+ e-)<0.3 GeV/c2 and 1<p(T)<5 GeV/c is measured in p+p and Au+Au collisions at square root(S(NN))=200 GeV. An enhanced yield above hadronic sources is observed. Treating the excess as photon internal conversions, the invariant yield of direct photons is deduced. In central Au+Au collisions, the excess of the direct photon yield over p+p is exponential in transverse momentum, with an inverse slope T=221+/-19(stat)+/-19(syst) MeV. Hydrodynamical models with initial temperatures ranging from T(init) approximately 300-600 MeV at times of approximately 0.6-0.15 fm/c after the collision are in qualitative agreement with the data. Lattice QCD predicts a phase transition to quark gluon plasma at approximately 170 MeV.

A novel liver-directed gene delivery system using an autonomously replicating vector specifically expressed in AFP positive hepatoma cells

A composite EBV-based expression vector, pEBAF, was constructed with the 5'-flanking sequence of human alpha-fetoprotein gene as a promoter. Complexed to galactosylated histone, this vector with a foreign DNA insertion could be transferred into hepatic cells via the asialoglycoprotein receptor mediated endocytosis pathway. It was replicated as an episome, and its expression was restricted to the AFP positive hepatoma cells. This new gene delivery method has the following advantages: (i) absence of a potential toxicity is related to viral vectors; (ii) the targeting is specific to AFP positive hepatoma cells; (iii) the introduction of the EBV replicon into this system results in the high level expression and long-term maintenance of the transferred gene. This novel gene delivery system has potential applications in gene therapy for the treatment of hepatocellular carcinoma.

The morphology of Au@MgO nanopeapods

The structure of metal nanoparticles embedded inside dielectric nanowires/nanotubes, namely nanopeapods, has been of increasing interest due to their unusual photoresponse and optical adsorption properties. This paper presents a type of new inorganic nanopeapod: faceted Au nanoparticles inside MgO nanowires. The Au self-assembles into a nanoparticle chain during the vapor-liquid-solid growth of the MgO nanowires for which gold also serves as the catalyst. Surprisingly such a chain can follow the whole axis of the MgO nanowires even if the latter zigzag, provided that the amount of gold is sufficient. It is shown that such Au@MgO nanopeapods form not only under metalorganic chemical vapor deposition conditions (Lai et al 2009 Appl. Phys. Lett. 94 022904), but also under our conventional vapor transport deposition condition. This new nanopeapod material might be a candidate for the study of electronic and/or plasmonic wave transport along nanowires.