Elliptic flow of charged particles in Pb-Pb collisions at sqrt[S(NN)] = 2.76 TeV

We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at sqrt[S(NN)] =2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|η|<0.8) and transverse momentum range 0.2<p t<5.0 GeV/c. The elliptic flow signal v₂, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 ± 0.002(stat) ± 0.003(syst) in the 40%-50% centrality class. The differential elliptic flow v₂ p t reaches a maximum of 0.2 near p t =3 GeV/c. Compared to RHIC Au-Au collisions at sqrt[S(NN)] 200 GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.

Charged-particle multiplicity density at midrapidity in central Pb-Pb collisions at sqrt[S(NN)] = 2.76 TeV

The first measurement of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at a center-of-mass energy per nucleon pair √ S NN = 2.76 TeV is presented. For an event sample corresponding to the most central 5% of the hadronic cross section, the pseudorapidity density of primary charged particles at midrapidity is 1584 ± 4(stat) ± 76(syst), which corresponds to 8.3 ± 0.4(syst) per participating nucleon pair. This represents an increase of about a factor 1.9 relative to pp collisions at similar collision energies, and about a factor 2.2 to central Au-Au collisions at √ S NN = 2.76 TeV. This measurement provides the first experimental constraint for models of nucleus-nucleus collisions at LHC energies.

Midrapidity antiproton-to-proton ratio in pp collisons at sqrt[s]=0.9 and 7 TeV measured by the ALICE experiment

The ratio of the yields of antiprotons to protons in pp collisions has been measured by the ALICE experiment at sqrt[s]=0.9 and 7 TeV during the initial running periods of the Large Hadron Collider. The measurement covers the transverse momentum interval 0.45<p_{t}<1.05  GeV/c and rapidity |y|<0.5. The ratio is measured to be R_{|y|<0.5}=0.957±0.006(stat)±0.014(syst) at 0.9 TeV and R_{|y|<0.5}=0.991±0.005(stat)±0.014(syst) at 7 TeV and it is independent of both rapidity and transverse momentum. The results are consistent with the conventional model of baryon-number transport and set stringent limits on any additional contributions to baryon-number transfer over very large rapidity intervals in pp collisions.

Storage and recall of weak coherent optical pulses with an efficiency of 25%

We demonstrate experimentally an efficient coherent rephasing scheme for the storage and recall of weak coherent light pulses in an inhomogeneously broadened optical transition in a Pr(3+):YSO crystal at 2.1 K. Precise optical pumping using a frequency stable (≈1  kHz linewidth) laser is employed to create a highly controllable atomic frequency comb structure. We report single photon level storage and retrieval efficiencies of 25%, based on coherent photon-echo-type reemission in the forward direction. The high efficiency is mainly a product of our highly controllable and precise ensemble-shaping technique. The coherence property of the quantum memory is proved through interference between a super-Gaussian pulse and the emitted echo.

Effects of low-voltage electrical stimulation and rapid chilling on meat quality characteristics of Chinese Yellow crossbred bulls

In this study, the effects of low-voltage electrical stimulation (LVES) and rapid chilling (RC) treatments on the quality characteristics of beef carcasses were evaluated, including the rate of pH and temperature decline, evaporative loss of carcasses, purge loss, cooking loss, and shear force values of m. longissimus steaks. Each carcass of 28 Chinese Yellow crossbred (SimmentalxYanbian) bulls was subjected to one of the four treatments, i.e., electrical stimulation and conventional chilling (ES/NR), electrical stimulation and rapid chilling (ES/RC), no electrical stimulation and rapid chilling (NE/RC), or no electrical stimulation and conventional chilling (NE/NR). Carcass pH and temperature were measured at 1, 3, 5, 7, 9, 11, and 24h post-mortem. After that, a 2.5-cm-thick m. longissimus steak was taken from the right side of each carcass and used for analyses of purge loss, cooking loss and Warner-Bratzler shear force (WBSF). The results showed that LVES accelerated the rate of carcass pH decline (P<0.05) and rapid chilling increased the rate of carcass temperature decline (P<0.05). There was no significant difference found for the mean carcass evaporative losses from all treatments (P>0.05). Mean purge losses for m. longissimus steaks from rapidly chilled carcasses were lower (P<0.05) than those from conventionally chilled carcasses. Electrical stimulation had no impact on m. longissimus steak purge losses (P>0.05). Rapid chilling significantly decreased (P<0.05) the cooking loss of m. longissimus steaks from electrically stimulated carcasses whilst it increased the cooking loss of m. longissimus steaks from carcasses without stimulation (P<0.05). LVES increased (P<0.05) cooking loss of m. longissimus steaks from conventionally chilled carcasses, but had no effect under the procedure of pre-rigor rapid chilling (P>0.05). The lowest mean shear force value was found for the ES/NR-treated m. longissimus steaks, whilst the highest one for the NE/RC-treated carcasses (P<0.05). Regression analyses indicated that carcass pH at 1h post-mortem was the most useful predictor for beef shear force. Abattoirs processing Chinese Yellow bulls could optimize meat quality by using low-voltage stimulation together with pre-rigor rapid chilling.

Acute toxicity of a single dose DATR, recombinant soluble human TRAIL mutant, in rodents and crab-eating macaques

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been reported to possess activity of inducing apoptosis in variety of tumor cells in preclinical models. Several mutational versions of TRAIL have been studied as promising agents for cancer therapy and the recombinant soluble human TRAIL mutant (DATR) is one of them. The objective of the present study was to provide possible toxic target organs and proposal non-toxic dose level of DATR for clinical usage. Rodents and crab-eating macaques were used to estimate potential adverse effects of DATR following a single dose administration. The median lethal dose (LD(50)) of intravenous injection to rats and mice was determined as 262.0 and 1018.0 mg/kg b.w., respectively. The LD(50) of intraperitoneal administration to mice was found to be 1432.1 mg/kg b.w. The main changes in macaques were found in the following aspects. Hematology analysis revealed an obvious decrease of red blood cell count (RBC), hemoglobin (HB) and hematocrit (HCT) after injection. Serum biochemical analysis showed an apparent increase of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), blood urea nitrogen (BUN) and creatinine (Crea). Furthermore, inflammatory cell infiltrate in liver and kidney was found by microscope. All the disorders suggested that liver, renal and hematological systems might be the target effectors of toxic effect induced by DATR. Based on the results of this study, the no observed-adverse-effect level (NOAEL) and the lowest observed-adverse-effect level of DATR in macaques are 90.0 and 135.0 mg/kg b.w., respectively.

Molecular Biomarkers of Columnar Cell Lesions Identified by Proteomic Approaches

The widespread increase in the use of screening mammography has led to a significant rise in the detection and diagnosis of benign breast disease (BBD), which encompasses a wide variety of non-cancerous changes including columnar cell lesions (CCL). Epidemiologic studies provide evidence for a relationship between BBD and subsequent risk of developing breast cancer. Observational studies have reported CCL are found adjacent to areas of tubular carcinoma and ductal and lobular carcinomas in situ and recently published molecular data state that genetic abnormalities frequently found in low grade ductal carcinoma in situ are also found in CCL. All these data support the hypothesis that CCL are the earliest morphologically distinguishable precursor lesions to low grade ductal carcinoma in situ and invasive carcinoma. However, BBD is heterogeneous and there is limited understanding of the biological importance associated with the spectrum of lesions. The lack of accurate molecular-based risk categories, therefore, hinders the ability of assigning prognostic significance to benign biopsy findings. The purpose of our study was to identify putative molecular markers of cancer progression from epithelial cells of BBD lesions. Regions of ductal hyperplasia (DH) and normal breast epithelium were isolated from mastectomy specimens using laser capture microdissection and extracted proteins were analyzed through proteomic approaches. Of the 1,500 total protein spots resolved by 2-dimensional electrophoresis, 98 were differentially expressed between DH and normal breast epithelial proteomes. Twenty-two proteins or related isoforms were identified using mass spectrometry. Two proteins of particular interest, NAD(P)H: quinone oxidoreductase 1 (NQO1) and galectin-3, were further investigated by immunohistochemistry (IHC) on cases diagnosed with BBD lesions. NQO1 was expressed sporadically in overtly normal epithelial cells lining breast ducts, but was overexpressed in BBD and tumor tissues. Notably, we found that a subpopulation of DH tissues with CCL stained positively for NQO1 and negatively for galectin-3. This finding has significance because CCL can only be diagnosed morphologically and the presence of CCL in biopsy specimens may indicate a precancerous lesion. However, sectioning artifacts associated with core biopsies can hinder morphological diagnosis of CCL, thus a means to additionally identify these lesions using IHC has tremendous value. Together, immunohistochemical staining of NQO1 and galectin-3 may prove to be clinically relevant in the identification of CCL in biopsy samples.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2142.

Immunophenotype of myeloid granulocytes: a pilot study for distinguishing myelodysplastic syndrome and aplastic anemia by flow cytometry

It is often difficult to distinguish myelodysplastic syndrome (MDS) from aplastic anemia (AA) because of the considerable clinical, cytologic histologic similarities between these two disorders; however, distinguishing between AA and MDS is of great importance because there is a higher risk of progression to acute leukemia in patients with MDS compared with AA. Up to now, CD34(+) cells in MDS and AA patients have been studied extensively; however, little information is available on myeloid granulocytes. The aim of this study was to determine whether immunophenotype of myeloid granulocytes in AA patients was different from that of MDS. Flow cytometry was used to assess the immunophenotype of myeloid granulocytes in 22 patients with MDS, 12 with AA, and 10 normal subjects. Our data showed that the percentages of CD13(+) granulocytes, CD33(+) granulocytes, CD34(+) granulocytes, and HLA-DR(+) granulocytes were significantly higher in patients with MDS than in AA patients and normal subjects (P < 0.05). The percentages of CD15(+) granulocytes and CD10(+) granulocytes were significantly lower in patients with MDS than in AA patients and normal subjects (P < 0.05). There were no significant differences in the expression of these markers between patients with AA and normal subjects (P > 0.05). As refractory anemia progressing to refractory anemia with excess blasts, the percentages of CD13(+) granulocytes, CD33(+) granulocytes, CD34(+) granulocytes and HLA-DR(+) granulocytes were significantly increased, whereas, the percentage of CD15(+) granulocytes was significantly decreased (P < 0.05). These data suggest that immunophenotype of myeloid granulocytes may be a useful parameter for the differential diagnosis of MDS and AA.

Summarizing Documents by Measuring the Importance of a Subset of Vertices within a Graph

This paper presents a novel method of generating extractive summaries for multiple documents. Given a cluster of documents, we firstly construct a graph where each vertex represents a sentence and edges are created according to the asymmetric relationship between sentences. Then we develop a method to measure the importance of a subset of vertices by adding a super-vertex into the original graph. The importance of such a super-vertex is quantified as super-centrality, a quantitative measure for the importance of a subset of vertices within the whole graph. Finally, we propose a heuristic algorithm to find the best summary. Our method is evaluated with extensive experiments. The comparative results show that the proposed method outperforms other methods on several datasets.