| 1. |
- Ablikim, M., et al.
(författare)
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Measurements of (XcJ)-> K+K-K+K- decays
- 2006
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 642:3, s. 197-202
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Tidskriftsartikel (refereegranskat)abstract
- Using 14M psi(2S) events taken with the BESII detector, chi(cJ) -> 2(K+K-) decays are studied. For the four-kaon final state, the branching fractions are B(chi(c0,1,2) ->.2(K+K-)) = (3.48 +/- 0.23 +/- 0.47) x 10(-3), (0.70 +/- 0.13 +/- 0.10) x 10(-3), and (2.17 +/- 0.20 +/- 0.31) x 10(-3). For the phi K+K- final state, the branching fractions, which are measured for the first time, are B(chi(c0,1,2) -> phi K+K-) = (1.03 +/- 0.22 +/- 0.15) x 10(-3), (0.46 +/- 0.16 +/- 0.06) x 10(-3), and (1.67 +/- 0.26 +/- 0.24) x 10(-4). For the phi phi final state, B(chi(c0,2) -> phi phi) = (0.94 +/- 0.21 +/- 0.13) x 10(-3) and (1.70 +/- 0.30 +/- 0.25) x 10(-3).
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| 2. |
- Schael, S, et al.
(författare)
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Precision electroweak measurements on the Z resonance
- 2006
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Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
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Forskningsöversikt (refereegranskat)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
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| 3. |
- Richards, Stephen, et al.
(författare)
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The genome of the model beetle and pest Tribolium castaneum.
- 2008
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Ingår i: Nature. - 1476-4687. ; 452:7190, s. 949-55
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Tidskriftsartikel (refereegranskat)abstract
- Tribolium castaneum is a representative of earth’s most numerous eukaryotic order, a powerful model organism for the study of generalized insect development, and also an important pest of stored agricultural products. We describe its genome sequence here. This omnivorous beetle has evolved an ability to interact with a diverse chemical environment as evidenced by large expansions in odorant and gustatory receptors, as well as p450 and other detoxification enzymes. Developmental patterns in Tribolium are more representative of other arthropods than those found in Drosophila, a fact represented in gene content and function. For one, Tribolium has retained more ancestral genes involved in cell-cell communication than Drosophila, and some are expressed in the growth zone crucial for axial elongation in short germ development. Systemic RNAi in T. castaneum appears to use mechanisms distinct from those found in C. elegans, but nevertheless offers similar power for the elucidation of gene function and identification of targets for selective insect control.
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| 4. |
- Wang, Mo-Jin, et al.
(författare)
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The Ile646Val (2073A > G) Polymorphism in the Kinase-Binding Domain of A-Kinase Anchoring Protein 10 and the Risk of Colorectal Cancer
- 2009
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Ingår i: ONCOLOGY. - : S. Karger AG. - 0030-2414 .- 1423-0232. ; 76:3, s. 199-204
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The purpose of this study is to investigate whether the Ile646Val (2073A>G) polymorphism in the kinase-binding domain of A-kinase anchoring protein 10 (AKAP10) is related to the risk of colorectal cancer (CRC), clinicopathological variables and the environmental factors for the development of CRC. Methods: Applying TaqMan allelic discrimination, we investigated AKAP10 Ile646Val (2073A>G) polymorphism in 288 Chinese CRC patients and 281 healthy controls. Results: Logistic regression analysis revealed a significant association of AKAP10 Ile646Val (2073A>G) polymorphism with increased CRC risk (adjusted OR = 1.44, 95% CI 1.01-2.07, p = 0.02). Stratification analysis showed that the increased risk associated with the variant genotypes (GG+AG) was more evident in male subjects (adjusted OR = 1.48, 95% CI 0.94-2.34, p = 0.03). Compared with the AA genotype, the adjusted OR for the variant genotypes was 1.81 (95% CI 1.08 - 3.05, p = 0.01) among young subjects (age ! 57 years). Among individuals who did not smoke or who smoked lightly, there was a significantly increased risk with the variant genotypes (adjusted OR = 1.66, 95% CI 1.08 - 2.56, p = 0.02). We did not observe a relationship between the AKAP10 polymorphism and other clinicopathological and environmental factors. Conclusions: Our data suggested that the AKAP10 2073A>G variation is associated with an increased risk of CRC in the Chinese population.
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| 5. |
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| 6. |
- Aamodt, K., et al.
(författare)
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The ALICE experiment at the CERN LHC
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 3:S08002
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Forskningsöversikt (refereegranskat)abstract
- ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries, Its overall dimensions are 16 x 16 x 26 m(3) with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008.
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| 7. |
- Abazov, V. M., et al.
(författare)
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Search for Higgs bosons decaying to tau pairs in p(p)over-bar collisions with the D0 detector
- 2008
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 101:7, s. 071804-:101, s. 071804-
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Tidskriftsartikel (refereegranskat)abstract
- We present a search for the production of neutral Higgs bosons phi decaying into tau(+)tau(-) final states in p (p) over bar collisions at a center-of-mass energy of 1.96 TeV. The data, corresponding to an integrated luminosity of approximately 1 fb(-1), were collected by the D0 experiment at the Fermilab Tevatron Collider. Limits on the production cross section times branching ratio are set. The results are interpreted in the minimal supersymmetric standard model yielding limits that are the most stringent to date at hadron colliders.
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| 8. |
- Adcox, K, et al.
(författare)
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Formation of dense partonic matter in relativistic nucleus-nucleus collisions at RHIC: Experimental evaluation by the PHENIX Collaboration
- 2005
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Ingår i: Nuclear Physics, Section A. - : Elsevier BV. - 0375-9474. ; 757:1-2, s. 184-283
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Forskningsöversikt (refereegranskat)abstract
- Extensive experimental data from high-energy nucleus-nucleus collisions were recorded using the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). The comprehensive set of measurements from the first three years of RHIC operation includes charged particle multiplicities, transverse energy, yield ratios and spectra of identified hadrons in a wide range of transverse momenta (PT), elliptic flow, two-particle correlations, nonstatistical fluctuations, and suppression of particle production at high PT. The results are examined with an emphasis on implications for the formation of a new state of dense matter. We find that the state of matter created at RHIC cannot be described in terms of ordinary color neutral hadrons.
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| 9. |
- Clark, Andrew G., et al.
(författare)
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Evolution of genes and genomes on the Drosophila phylogeny
- 2007
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 450:7167, s. 203-218
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Tidskriftsartikel (refereegranskat)abstract
- Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species.
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| 10. |
- Elsik, Christine G., et al.
(författare)
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The Genome Sequence of Taurine Cattle : A Window to Ruminant Biology and Evolution
- 2009
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 324:5926, s. 522-528
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Tidskriftsartikel (refereegranskat)abstract
- To understand the biology and evolution of ruminants, the cattle genome was sequenced to about sevenfold coverage. The cattle genome contains a minimum of 22,000 genes, with a core set of 14,345 orthologs shared among seven mammalian species of which 1217 are absent or undetected in noneutherian (marsupial or monotreme) genomes. Cattle-specific evolutionary breakpoint regions in chromosomes have a higher density of segmental duplications, enrichment of repetitive elements, and species-specific variations in genes associated with lactation and immune responsiveness. Genes involved in metabolism are generally highly conserved, although five metabolic genes are deleted or extensively diverged from their human orthologs. The cattle genome sequence thus provides a resource for understanding mammalian evolution and accelerating livestock genetic improvement for milk and meat production.
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| 11. |
- Han, Y., et al.
(författare)
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X-Radiation Induces Non-Small-Cell Lung Cancer Apoptosis by Upregulation of Axin Expression
- 2009
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Ingår i: International Journal of Radiation Oncology Biology Physics. - : Elsevier BV. - 0360-3016. ; 75:2, s. 518-526
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Axis inhibition (Axin) is an important negative regulator of the Wnt pathway. This study investigated the relationship between Axin expression and sensitivity to X-rays in non-small-cell lung cancer (NSCLC) to find a useful indicator of radiosensitivity. Methods and Materials: Tissue from NSCLC patients, A549 cells, and BE1 cells expressing Axin were exposed to 1-Gy of X-radiation. Axin and p53 expression levels were detected by immunohistochemistry and reverse transcription-PCR. Apoptosis was determined by TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling) assay and FACS (fluorescence-activate cell sorter) analysis. Caspase-3 activity was determined by Western blotting. Phospho-JNK expression was determined by immunofluorescence. Results: The expression of Axin was significantly lower in NSCLC tissues than in normal lung tissues (p less than 0.05). Axin expression correlates with differentiation, TNM staging, and lymph node metastasis of NSCLC (p less than 0.05). Its expression negatively correlates with the expression of p53(mt) (p=0.000) and positively correlates with apoptosis (p=0.002). The prognosis of patients with high expression of Axin was better than those with low expression. X-radiation increases Axin expression in NSCLC tissue, and caspase-3 is significantly higher in samples in which Axin is increased (p less than 0.05). Both X-radiation and Axin induce apoptosis of A549 and BE1 cells; however, the combination of the two enhances the apoptotic effect (p less than 0.05). In A549 cells, inhibition of p53 blocks Axin-induced apoptosis, whereas in BE1 cells, the JNK pathway is required. Conclusions: Axin induces the p53 apoptotic pathway in cells where this pathway is intact; however, in cells expressing p53(mt), Axin induces apoptosis via the JNK pathway. Elevated Axin expression following X-ray exposure is a reliable indicator for determining the radiosensitivity of NSCLC.
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| 12. |
- Lan, Ting, et al.
(författare)
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Extensive functional diversification of the Populus glutathione S-transferase supergene family
- 2009
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Ingår i: The Plant Cell. - : Oxford University Press (OUP). - 1040-4651 .- 1532-298X. ; 21:12, s. 3749-3766
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Tidskriftsartikel (refereegranskat)abstract
- Identifying how genes and their functions evolve after duplication is central to understanding gene family radiation. In this study, we systematically examined the functional diversification of the glutathione S-transferase (GST) gene family in Populus trichocarpa by integrating phylogeny, expression, substrate specificity, and enzyme kinetic data. GSTs are ubiquitous proteins in plants that play important roles in stress tolerance and detoxification metabolism. Genome annotation identified 81 GST genes in Populus that were divided into eight classes with distinct divergence in their evolutionary rate, gene structure, expression responses to abiotic stressors, and enzymatic properties of encoded proteins. In addition, when all the functional parameters were examined, clear divergence was observed within tandem clusters and between paralogous gene pairs, suggesting that subfunctionalization has taken place among duplicate genes. The two domains of GST proteins appear to have evolved under differential selective pressures. The C-terminal domain seems to have been subject to more relaxed functional constraints or divergent directional selection, which may have allowed rapid changes in substrate specificity, affinity, and activity, while maintaining the primary function of the enzyme. Our findings shed light on mechanisms that facilitate the retention of duplicate genes, which can result in a large gene family with a broad substrate spectrum and a wide range of reactivity toward different substrates.
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| 13. |
- Luo, W., et al.
(författare)
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Structural phase transitions in brookite-type TiO2 under high pressure
- 2005
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Ingår i: Solid State Communications. - : Elsevier BV. - 0038-1098 .- 1879-2766. ; 133:1, s. 49-53
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Tidskriftsartikel (refereegranskat)abstract
- We have studied polycrystalline brookite TiO2 using energy-dispersive X-ray diffraction at pressures up to 27.8 GPa and derived an ambient-pressure bulk modulus of 255 GPa using Birch-Murnaghan's equations of state with a fixed value of 4 as its first derivative. The transition from brookite-type to baddeleyite-type was observed to start at 15.8 GPa and finished at 22.8 GPa. Upon decompression, the alpha-PbO2 structure appeared at 3.5 GPa and the baddeleyite-type structure remained down to 1.6 GPa. the lowest pressure in the present work.
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| 14. |
- Meng, Wen-Jian, et al.
(författare)
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Microsatellite instability did not predict individual survival in sporadic stage II and III rectal cancer patients
- 2007
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Ingår i: Oncology. - : S. Karger AG. - 0890-9091 .- 0030-2414 .- 1423-0232. ; 72:1-2, s. 82-88
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Tumors with high-frequency microsatellite instability (MSI-H) have unique biological behavior and the predictive role of microsatellite instability (MSI) status on survival of colorectal cancer is still debated. The prognostic significance of MSI status in sporadic stage II and III rectal cancer patients needs to be more precisely defined. So we investigated the relationship between MSI status and clinicopathological features and prognosis in these patients. Methods: DNAs from fresh-frozen paired samples of tumors and corresponding normal tissue from 128 stage II and III rectal cancer patients were analyzed for MSI by PCR amplification using markers recommended by a National Cancer Institute workshop on MSI. To assess prognostic significance, Cox proportional hazards modeling was used. Results: Twelve (9.3%) tumors in our study were MSI-H, 28 (21.9%) were low-frequency MSI (MSI-L) and 88 (68.8%) were microsatellite stable (MSS). Most of the MSI-H tumors compared with MSI-L and MSS tumors were found in female patients (p = 0.031), had mucinous histology (p = 0.023), high grade of differentiation (p = 0.002) and high level of preoperative serum carcinoembryonic antigen (p = 0.005). Rectal cancer patients with MSI-H did not show a better clinical outcome than those with MSI-L/MSS, neither in all cases (p = 0.986) nor in stage II and stage III disease analyzed separately (p = 0.705 and p = 0.664, respectively). Conclusions: Data provided here demonstrated there was high incidence of MSI-H and MSI was not a prognostic factor in sporadic stage II and III rectal cancers from the Chinese Han population included in this study. Tumor stage is more suitable than MSI status for prediction of individual survival in sporadic stage II and III rectal cancer patients. Copyright © 2007 S. Karger AG.
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| 15. |
- Meng, Wen-Jian, et al.
(författare)
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Novel mutations and sequence variants in exons 3-9 of human T Cell Factor-4 gene in sporadic rectal cancer patients stratified by microsatellite instability
- 2007
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Ingår i: World Journal of Gastroenterology. - 1007-9327 .- 2219-2840. ; 13:27, s. 3747-3751
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To establish the role of human T Cell Factor-4 (hTCF-4) gene exons 3-9 mutation status in association with sporadic rectal cancer with microsatellite instability (MSI). Methods: Microsatellite markers were genotyped in 93 sporadic rectal cancer patients. Eleven cases were found to be high-frequency MSI (MSI-H). Sequence analysis of the coding region of the exons 3-9 of hTCF-4 gene was carried out for the 11 MSI-H cases and 10 controls (5 microsatellite stability (MSS) cases and 5 cases with normal mucosa). The sequencing and MSI identification were used. Results: Several novel mutations and variants were revealed. In exon 4, one is a 4-position continuous alteration which caused amino acid change from Q131T and S132I (391insA, 392 G > A, 393 A > G and 395delC) and another nucleotide deletion (395delC) is present in MSI-H cases (5/10 and 4/10, respectively) but completely absent in the controls. Conclusion: Novel mutations in exon 4 of hTCF-4 gene were revealed in this study, which might be of importance in the pathogenesis of sporadic rectal cancer patients with MSI-H. © 2007 WJG. All rights reserved.
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| 16. |
- Rich, Rebecca L., et al.
(författare)
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A global benchmark study using affinity-based biosensors
- 2009
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Ingår i: Analytical Biochemistry. - : Elsevier BV. - 0003-2697 .- 1096-0309. ; 386:2, s. 194-216
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Tidskriftsartikel (refereegranskat)abstract
- To explore the variability in biosensor studies, 150 participants from 20 countries were given the same protein samples and asked to determine kinetic rate constants for the interaction. We chose a protein system that was amenable to analysis using different biosensor platforms as well as by users of different expertise levels. The two proteins (a 50-kDa Fab and a 60-kDa glutathione S-transferase [GST] antigen) form a relatively high-affinity complex, so participants needed to optimize several experimental parameters, including ligand immobilization and regeneration conditions as well as analyte concentrations and injection/dissociation times. Although most participants collected binding responses that could be fit to yield kinetic parameters, the quality of a few data sets could have been improved by optimizing the assay design. Once these outliers were removed, the average reported affinity across the remaining panel of participants was 620 pM with a standard deviation of 980 pM. These results demonstrate that when this biosensor assay was designed and executed appropriately, the reported rate constants were consistent, and independent of which protein was immobilized and which biosensor was used.
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| 17. |
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| 18. |
- Wang, Chao-Jie, et al.
(författare)
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Clinicopathological significance of microRNA-31, -143 and -145 expression in colorectal cancer
- 2009
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Ingår i: Disease Markers. - 0278-0240 .- 1875-8630. ; 26:1, s. 27-34
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Tidskriftsartikel (refereegranskat)abstract
- We are just beginning to understand how microRNAs (miRNAs) are involved in tumor-related processes in humans. Applying real-time RT-PCR, we investigated the miR-31, miR-143 and miR-145 expression in 98 primary CRC specimens, along with the corresponding normal mucosa specimens, and analyze the relationship of their expression with clinicopathological features. Our results showed the miR-31 expression was up-regulated in CRC compared to normal mucosa (p = 0.001). Furthermore, miR-31 expression was positively related to advanced TNM stage (p = 0.026) and deeper invasion of tumors (p = 0.024). MiR-145 was down-regulated in both colon (p = 0.001) and rectal (p = 0.012) cancer. MiR-143 was only down-regulated in colon cancer (p = 0.023) but not in rectal cancer (p = 0.351). There was no relationship of miR-143 and miR-145 expression with other clinicopathological features (p > 0.05), except that the miR-145 expression was related to cancer site (p = 0.03). In conclusion, the miR-31 overexpression may be involved in the development and progression of CRC. The miR-143 and miR-145 may play a certain role in the development of colon and/or rectal cancers but not in progression of the disease.
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| 19. |
- Wang, Hui, et al.
(författare)
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Attenuation of phagocytosis of xenogeneic cells by manipulating CD47.
- 2007
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 109:2, s. 836-42
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Tidskriftsartikel (refereegranskat)abstract
- Signal regulatory protein alpha (SIRPalpha) is a critical immune inhibitory receptor on macrophages, and its interaction with CD47, a ligand for SIRPalpha, prevents autologous phagocytosis. We hypothesized that interspecies incompatibility of CD47 may contribute to the rejection of xenogeneic cells by macrophages. Here, we show that pig CD47 does not interact with mouse SIPRalpha. Similar to CD47-/- mouse cells, porcine red blood cells (RBCs) failed to induce SIRPalpha tyrosine phosphorylation in mouse macrophages. Blocking SIRPalpha with antimouse SIRPalpha mAb (P84) significantly enhanced the phagocytosis of CD47+/+ mouse cells, but did not affect the engulfment of porcine or CD47-/- mouse cells by mouse macrophages. CD47-deficient mice, whose macrophages do not phagocytose CD47-/- mouse cells, showed markedly delayed clearance of porcine RBCs compared with wild-type mouse recipients. Furthermore, mouse CD47 expression on porcine cells markedly reduced their phagocytosis by mouse macrophages both in vitro and in vivo. These results indicate that interspecies incompatibility of CD47 contributes significantly to phagocytosis of xenogeneic cells by macrophages and suggest that genetic manipulation of donor CD47 to improve its interaction with the recipient SIRPalpha may provide a novel approach to prevent phagocyte-mediated xenograft rejection.
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| 20. |
- Wang, Hui, et al.
(författare)
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Lack of CD47 on nonhematopoietic cells induces split macrophage tolerance to CD47null cells
- 2007
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National academy of sciences. - 0027-8424 .- 1091-6490. ; 104:34, s. 13744-13749
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Tidskriftsartikel (refereegranskat)abstract
- Macrophages recognize CD47 as a marker of "self" and phagocytose CD47null hematopoietic cells. Using CD47 chimera models, here, we show that the phagocytic activity of macrophages against CD47null hematopoietic cells is conferred by CD47 expression on nonhematopoietic cells, and this "education" process is hematopoietic cell-independent. Macrophages in the chimeras where nonhematopoietic cells express CD47 phagocytose CD47null cells, whereas those in the chimeras lacking CD47 on nonhematopoietic cells are tolerant to CD47null cells. However, macrophages in the latter chimeras retain phagocytic activity against CD47null RBCs, demonstrating a split macrophage tolerance to CD47null hematopoietic cells. The findings highlight the potential importance of nonhematopoietic cells in the regulation of macrophage function, and suggest a previously uncharacterized mechanism of macrophage tolerance.
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| 21. |
- Wang, Xiangdong, et al.
(författare)
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Potential effects of peroxisome proliferator-activated receptor activator on LPS-induced lung injury in rats
- 2009
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Ingår i: Pulmonary Pharmacology & Therapeutics. - : Elsevier BV. - 1522-9629 .- 1094-5539. ; 22:4, s. 318-325
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Tidskriftsartikel (refereegranskat)abstract
- Multiple factors contribute to the pathogenesis and prognosis of chronic obstructive pulmonary disease (COPD), still requiring new therapeutic strategies and medications for the disease. The aim of the present study is to investigate the model of lipopolysaccharide (LPS)-induced chronic lung injury and hyperinflation and test therapeutic effects of peroxisome proliferator-activated receptor (PPAR)-gamma agonist. Wister rats were challenged with intra-tracheal instillation of LPS at concentrations of 0.006, 0.060, 0.600, and 6.000 mg/ml per kg, twice a week, for 1, 2, 4 and 6 weeks. PPAR activator, 15-deoxy-Delta(12,14)-prostaglandin J2 (15D-PGJ2), or vehicle (PBS) was administered orally and daily at the dose of 1 and 10 mg/ml per kg in animals challenged with LPS or PBS at the dose of 0.060 mg/ml per kg body weight twice a week for 4 weeks. We found that intra-tracheal exposure of LPS resulted in a dose-dependent pattern of chronic lung hyperinflation and hypertrophy, increased alveolar enlargement, reduced vascular endothelial growth factor (VEGF) and elevated tissue inhibitor of metalloproteinases (TIMP)-1 levels in bronchoalveolar lavage (BAL) fluid, and early changes of leukocyte influx and interferon (IFN)-gamma levels in bronchoalveolar lavage (BAL) fluid. PPAR-gamma agonist ameliorated these changes related with the dose used. LPS-induced lung disease model shows some similarities with human disease, and PPAR-gamma agonist may be an alternative for COPD therapy. (C) 2009 Elsevier Ltd. All rights reserved.
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| 22. |
- Wang, Yong, et al.
(författare)
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mRNA expression of minichromosome maintenance 2 in colonic adenoma and adenocarcinoma
- 2009
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Ingår i: EUROPEAN JOURNAL OF CANCER PREVENTION. - 0959-8278. ; 18:1, s. 40-45
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Tidskriftsartikel (refereegranskat)abstract
- As proliferation is essential for Progression from normal cells to tumor, certain markers specific to proliferating cells may permit detection of premalignant lesions. Here, we aimed to evaluate the possible value of a proliferation marker, minichromosome maintenance 2 (MCM2), in the early diagnosis of colorectal cancer, by analyzing the difference in MCM2 expression among normal mucosa, adenoma, and adenocarcinoma, and investigating the relationship of MCM2 expression in adenomas with clinicopathologic variables. Using immunohistochemistry and real-time reverse transcription-PCR, we observed that the expression of MCM2 protein was present on basal third to half of colonic crypts in normal mucosa, whereas throughout the epithelium in adenomas and adenocarcinomas, the expression of MCM2 mRNA in adenocarcinomas was significantly higher than in adenomas (P=0.001), whereas the difference between adenoma and normal mucosa was not significant (P=0.184); we also found that the expression of MCM2 mRNA tended to be increased in the adenomas with high-grade dysplasia, or in older patients, respectively, compared with those with low-grade dysplasia, and younger patients. These results suggested the potential value of MCM2 in early diagnosis of colorectal cancer.
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| 23. |
- Xu, Bing, et al.
(författare)
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Clinicopathological significance of caspase-8 and caspase-10 expression in rectal cancer
- 2008
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Ingår i: Oncology. - : S. Karger AG. - 0890-9091 .- 0030-2414 .- 1423-0232. ; 74:3-4, s. 229-236
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To investigate the expression of caspase-8 and -10 in rectal adenoma, adenocarcinoma and the corresponding normal mucosa tissue, and to clarify the relationship between their expression and clinicopathological parameters of rectal cancer. Methods: The expression of caspase-8 and -10 was determined by real-time RT-PCR and immunohistochemistry in 36 rectal adenomas, 93 rectal cancers and 93 corresponding normal rectal mucosa samples. Results: Compared with normal mucosa, the mRNA expression of caspase-8 was higher in adenomas (p = 0.003), while that of caspase-10 was lower in adenomas (p = 0.035) and cancers (p = 0.001). Immunohistochemical results showed caspase-8 up-regulation in adenomas (p = 0.014), and caspase-10 down-regulation in adenomas (p = 0.034) and cancers (p < 0.001) compared with normal mucosa samples. Cancers with poor differentiation had lower caspase-10 mRNA and protein levels than those with better differentiation (p = 0.041 and p = 0.046, respectively). The protein expression of caspase-8 and -10 was in accordance with the mRNA expression (p = 0.043 and p = 0.018, respectively). Conclusions: Caspase-8 expression was up-regulated in rectal adenomas. Caspase-10 expression was down-regulated in both rectal adenomas and cancers, and was further related to differentiation. Caspase-8 and -10 may be involved in the pathogenesis of rectal cancer. Copyright © 2008 S. Karger AG.
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| 24. |
- Yang, Han-Xin, et al.
(författare)
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Diversity-optimized cooperation on complex networks
- 2009
-
Ingår i: Physical Review E. Statistical, Nonlinear, and Soft Matter Physics. - : American physical society. - 1063-651X .- 1095-3787. ; 79:5, s. 056107-
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Tidskriftsartikel (refereegranskat)abstract
- We propose a strategy for achieving maximum cooperation in evolutionary games on complex networks. Each individual is assigned a weight that is proportional to the power of its degree, where the exponent α is an adjustable parameter that controls the level of diversity among individuals in the network. During the evolution, every individual chooses one of its neighbors as a reference with a probability proportional to the weight of the neighbor, and updates its strategy depending on their payoff difference. It is found that there exists an optimal value of α, for which the level of cooperation reaches maximum. This phenomenon indicates that, although high-degree individuals play a prominent role in maintaining the cooperation, too strong influences from the hubs may counterintuitively inhibit the diffusion of cooperation. Other pertinent quantities such as the payoff, the cooperator density as a function of the degree, and the payoff distribution are also investigated computationally and theoretically. Our results suggest that in order to achieve strong cooperation on a complex network, individuals should learn more frequently from neighbors with higher degrees, but only to a certain extent.
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| 25. |
- Yang, Jinghai, et al.
(författare)
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Investigation on the origin of green light emission in ZnO bulk materials
- 2009
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Ingår i: INTERNATIONAL JOURNAL OF MATERIALS and PRODUCT TECHNOLOGY. - 0268-1900. ; 34:3, s. 360-368
-
Tidskriftsartikel (refereegranskat)abstract
- ZnO bulk materials were implanted by O and Zn with different concentration and their photoluminescence (PL) properties were investigated in detail. The results clearly show that O and Zn implantation indeed have great influence on the green light emission. By comparing the PL spectra for the samples with different implantations, O-i, Zn-i and Cu-related defects have been excluded from the possibility of the origin of green light emission step by step. Finally, it can be concluded that V-Zn is responsible to the observed green light emission, which has good agreement with the theoretical results from first principle calculation.
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| 26. |
- Yang, L., et al.
(författare)
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Compact 2x2 tapered multimode interference couplers based on SU-8 polymer rectangular waveguides
- 2008
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 93:20
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Tidskriftsartikel (refereegranskat)abstract
- A 2x2 tapered multimode interference (MMI) coupler is designed and fabricated by using air-cladded SU-8 rectangular waveguide, which is effective in reducing the device size and improving the self-imaging quality. The parabolically tapered MMI section is used to reduce further the size of the MMI coupler. A compact 2x2 coupler with a total MMI size of about 5.3x34.2 mu m(2) is demonstrated and characterized. The measurement results show that the fabricated 2x2 MMI coupler has relatively small excess loss and nonuniformity for both polarizations in a broad wavelength range (from 1480 to 1630 nm).
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| 27. |
- Yang, Yang, et al.
(författare)
-
Detection of Bronchial Function of NHBD Lung Following One-h Warm Ischemia by Organ Bath Model
- 2009
-
Ingår i: Journal of Huazhong University of Science and Technology-Medical Sciences. - : Springer Science and Business Media LLC. - 1993-1352 .- 1672-0733. ; 29:3, s. 340-343
-
Tidskriftsartikel (refereegranskat)abstract
- This study investigated the feasibility and effects of organ bath to be used for detection of bronchial function of non-heart-beating donor (NHBD) lung after 1-h warm ischemia. Sixteen Swedish pigs were divided into two groups randomly: heart-beating donor (HBD) group and NHBD with 1-h warm ischemia (NHBD-1 h) group. The bronchial rings whose lengths and inner diameters were both 1.5 mm were obtained from isolated left lungs of all the pigs. Acetylcholine, arachidonic acid natrium and papaverine were used to test and compare the contractile and relaxant function of bronchial smooth muscles and epithelium-dependent relaxation (EpiDR) response between HBD and NHBD-1 h groups. The results showed that there was no significant difference in the values of bronchial precontraction between HBD and NHBD-1 h groups (5.18 +/- 0.07 vs 5.10 +/- 0.11 mN, P > 0.05). No significant difference in the values of EpiDR responses between HBD and NHBD-1 h groups (1.26 +/- 0.05 vs 1.23 +/- 0.07 mN, P > 0.05) was observed either. During the process of EpiDR induction, the rings had no spontaneous relaxation in two groups. In addition, papaverine solution completely relaxed the bronchial smooth muscles of all bronchial rings. It was concluded that after warm ischemia for 1 h, the contractile and relaxant abilities of bronchial smooth muscles, and the epithelium-dependent adjustment both kept intact. Organ bath model could be a liable and scientific way to evaluate the bronchial function of NHBD lung.
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| 28. |
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| 29. |
- Zhang, Jin-Ting, et al.
(författare)
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Nuclear to cytoplasmic shift of p33ING1b protein from normal oral mucosa to oral squamous cell carcinoma in relation to clinicopathological variables
- 2008
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Ingår i: Journal of Cancer Research and Clinical Oncology. - : Springer Science and Business Media LLC. - 0171-5216 .- 1432-1335. ; 134:3, s. 421-426
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: p33ING1b, as a candidate tumour suppressor gene, has been found to be expressed a proportion of oral squamous cell carcinomas (OSCCs), however, its clinicopathological significance is not studied yet. Our aim was to investigate association of p33ING1b expression with clinicopathological variables and particularly interesting new cysteine-histidine rich protein (PINCH) in OSCCs. Methods: p33ING1b expression was immumohistochemically examined in 20 normal oral mucosa specimens and 49 OSCCs. Results: Normal squamous cells showed only p33ING1b nuclear expression (no cytoplasmic expression), with a rate of 90% positive cases. While 24% of OSCCs appeared cytoplasmic expression (11 of them with weak nuclear staining) and the rest tumours (76%) were negative for p33 ING1b. Furthermore, the cases having lymph node metastasis showed a higher frequency of positive cytoplasmic expression than those without metastasis (P = 0.03). The p33ING1b cytoplasmic expression was positively related to PINCH expression (P = 0.04), the cases positive for both proteins had a high rate of the metastasis (P = 0.03). Conclusions: The transfer of p33ING1b protein from the nucleus to the cytoplasm may result in loss of normal cellular function of the protein, which might play a role in the tumourigenesis and metastasis of OSCCs. © 2007 Springer-Verlag.
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| 30. |
- Zhang, JT, et al.
(författare)
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Up-regulation of PINCH in the stroma of oral squamous cell carcinoma predicts nodal metastasis
- 2005
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Ingår i: Oncology Reports. - 1021-335X .- 1791-2431. ; 14:6, s. 1519-1522
-
Tidskriftsartikel (refereegranskat)abstract
- Particularly interesting new cysteine-histidine rich protein (PINCH), an adapter protein involved in integrin and growth factor signalling, is up-regulated in the stroma of colorectal, breast, prostate, lung and skin cancer. Strong stromal immunostaining for PINCH is an independent prognostic indicator for reduced survival in colorectal cancer, suggesting that PINCH is involved in the signalling that promotes tumour progression. Since no study on PINCH has been carried out in oral squamous cell carcinoma (OSCC), this study aimed to determine PINCH expression in OSCC and its clinicopathological significance. PINCH protein expression was examined by immunohistochemistry in 20 normal oral mucosa and in 57 OSCC specimens, The frequency of strong PINCH immunostaining was higher in tumour-associated stroma of OSCC (37%) as compared to normal oral mucosa (10%) (p=0.02). Strong PINCH stromal immunostaining predicted nodal metastasis: 19/26 (73%) OSCC cases with nodal metastasis had strong PINCH immunostaining compared to 9/31 (29%) cases without nodal metastasis (p=0.02). The PINCH expression in OSCC was more intense in stroma at the invasive edge than in intratumoural stroma. In conclusion, the up-regulation of PINCH protein in stroma may be involved in promoting invasion and metastasis in OSCC.
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| 31. |
- Zhu, Zhenlong, et al.
(författare)
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PINCH expression and its significance in esophageal squamous cell carcinoma
- 2008
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Ingår i: Disease Markers. - : Hindawi Limited. - 0278-0240 .- 1875-8630. ; 25:2, s. 75-80
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Tidskriftsartikel (refereegranskat)abstract
- Particularly interesting new cysteine-histidine rich protein (PINCH), as a newly discovered protein of LIM family members, may play a role in signal transduction of integrin and growth factor, and involved in the incidence and development of tumors. PINCH protein is overexpressed in tumor-associated stroma of several types of tumors. However, there is no study of the PINCH in esophageal cancer, therefore we investigated PINCH expression in esophageal squamous cell carcinomas and its clinicopathogical significance in the patients. PINCH expression was immunohistochemically examined in 20 normal esophageal samples and 64 esophageal squamous cell carcinomas. The results showed that PINCH expression in the stroma of cancers was heterogeneous, and its positive rate (56%) was higher than that of normal esophageal mucosa (5%, p<0.0001). The stronger staining was observed at the invasive edge of tumor when compared to the inner area of tumor. The rate of positive PINCH (90%) in the cases with lymph node metastasis was higher than that (41%) in the cases without metastasis (p<0.0001). PINCH expression was not correlated with patients’ gender, age, tumor location, size and differentiation (p>0.05). The results suggest that PINCH protein may be a marker of tumor associated-stroma involving tumor development, and predicting the ability of invasion and metastasis of esophageal squamous cell carcinoma.
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| 32. |
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| 33. |
- Abazov, M, et al.
(författare)
-
Combination of t(t)over-bar cross section measurements and constraints on the mass of the top quark and its decays into charged Higgs bosons
- 2009
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 80, s. 071102-
-
Tidskriftsartikel (refereegranskat)abstract
- We combine measurements of the top quark pair production cross section in p (p) over bar collisions in the l + jets, ll, and tau l final states ( where l is an electron or muon) at a center of mass energy of root s = 1.96 TeV in 1 fb(-1) of data collected with the D0 detector. For a top quark mass of 170 GeV/c(2), we obtain sigma(t (t) over bar) = 8.18(-0.87)(+0.98) pb in agreement with the theoretical prediction. Based on predictions from higher order quantum chromodynamics, we extract a mass for the top quark from the combined t (t) over bar cross section, consistent with the world average of the top quark mass. In addition, the ratios of t (t) over bar cross sections in different final states are used to set upper limits on the branching fractions B(t -> H(+)b -> tau(+) vb) and B(t -> H(+)b -> c (s) over barb) as a function of the charged Higgs boson mass.
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| 34. |
- Abazov, M, et al.
(författare)
-
Direct Measurement of the Mass Difference between Top and Antitop Quarks
- 2009
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 103:13, s. 132001-
-
Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the mass difference between t and (t) over bar quarks in lepton + jets final states of t (t) over bar events in 1 fb(-1) of data collected with the D0 detector from Fermilab Tevatron Collider p (p) over bar collisions at root s = 1.96 TeV. The measured mass difference of 3.8 +/- 3.7 GeV is consistent with the equality of t and (t) over bar masses. This is the first direct measurement of a mass difference between a quark and its antiquark partner.
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| 35. |
- Abazov, M, et al.
(författare)
-
Direct Measurement of the W Boson Width
- 2009
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 103:23, s. 231802-
-
Tidskriftsartikel (refereegranskat)abstract
- We present a direct measurement of the width of the W boson using the shape of the transverse mass distribution of W -> e nu candidate events. Data from approximately 1 fb(-1) of integrated luminosity recorded at s=1.96 TeV by the D0 detector at the Fermilab Tevatron pp collider are analyzed. We use the same methods and data sample that were used for our recently published W boson mass measurement, except for the modeling of the recoil, which is done with a new method based on a recoil library. Our result, 2.028 +/- 0.072 GeV, is in agreement with the predictions of the standard model.
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| 36. |
- Abazov, M, et al.
(författare)
-
Evidence of WW and WZ Production with lepton plus jets Final States in pp Collisions at root s=1.96 TeV
- 2009
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:16, s. 161801-
-
Tidskriftsartikel (refereegranskat)abstract
- We present first evidence for WW+WZ production in lepton+jets final states at a hadron collider. The data correspond to 1.07 fb(-1) of integrated luminosity collected with the D0 detector at the Fermilab Tevatron in pp collisions at root s=1.96 TeV. The observed cross section for WW+WZ production is 20.2 +/- 4.5 pb, consistent with the standard model and more precise than previous measurements in fully leptonic final states. The probability that background fluctuations alone produce this excess is < 5.4x10(-6), which corresponds to a significance of 4.4 standard deviations.
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| 37. |
- Abazov, M, et al.
(författare)
-
Measurement of differential Z/gamma* plus jet plus X cross sections in p(p)over-bar collisions at root S=1.96 TeV
- 2008
-
Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 669:5, s. 278-286
-
Tidskriftsartikel (refereegranskat)abstract
- We present new measurements of differential cross sections for Z/gamma* (-> mu mu) + jet + X production in a 1 fb(-1) data sample collected with the DO detector in p (p) over bar collisions at root s = 1.96 TeV. Results include the first measurements differential in the Z/gamma* transverse momentum and rapidity, as well as new measurements differential in the leading jet transverse momentum and rapidity. Next-to-leading order perturbative QCD predictions are compared to the measurements, and reasonable agreement is observed, except in the region of low Z/gamma* transverse momentum. Predictions from two event generators based on matrix elements and parton showers, and one pure parton shower event generator are also compared to the measurements. These show significant overall normalization differences to the data and have varied success in describing the shape of the distributions.
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| 38. |
- Abazov, M, et al.
(författare)
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Measurement of Dijet Angular Distributions at s=1.96 TeV and Searches for Quark Compositeness and Extra Spatial Dimensions
- 2009
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 103:19, s. 191803-
-
Tidskriftsartikel (refereegranskat)abstract
- We present the first measurement of dijet angular distributions in pp collisions at s=1.96 TeV at the Fermilab Tevatron Collider. The measurement is based on a dataset corresponding to an integrated luminosity of 0.7 fb(-1) collected with the D0 detector. Dijet angular distributions have been measured over a range of dijet masses, from 0.25 TeV to above 1.1 TeV. The data are in good agreement with the predictions of perturbative QCD and are used to constrain new physics models including quark compositeness, large extra dimensions, and TeV-1 scale extra dimensions. For all models considered, we set the most stringent direct limits to date.
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| 39. |
- Abazov, M, et al.
(författare)
-
Measurement of gamma + b + X and gamma + c + X Production Cross Sections in pp > Collisions at s=1.96 TeV
- 2009
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:19, s. 192002-
-
Tidskriftsartikel (refereegranskat)abstract
- First measurements of the differential cross sections d(3)sigma/(dp(T)(gamma)dy(gamma)dy(jet)) for the inclusive production of a photon in association with a heavy quark (b, c) jet are presented, covering photon transverse momenta 30 < p(T)(gamma)< 150 GeV, photon rapidities |y(gamma)|< 1.0, jet rapidities |y(jet)|< 0.8, and jet transverse momenta p(T)(jet)> 15 GeV. The results are based on an integrated luminosity of 1 fb(-1) in pp collisions at s=1.96 TeV recorded with the D0 detector at the Fermilab Tevatron Collider. The results are compared with next-to-leading order perturbative QCD predictions.
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| 40. |
- Abazov, M, et al.
(författare)
-
Measurement of the t(t)over-bar production cross section and top quark mass extraction using dilepton events in p(p)over-bar collisions
- 2009
-
Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 679:3, s. 177-185
-
Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the top quark pair production cross section in p (p) over bar collisions at root s = 1.96 TeV using approximately 1 fb(-1) collected with the DO detector. We consider decay channels containing two high p(T) charged leptons where one lepton is identified as an electron or a muon while the other lepton can be an electron, a muon or a hadronically decaying tau lepton. For a mass of the top quark of 170 GeV, the measured cross section is 7.5(-1.0)(+1.0)(stat)(-0.6)(+0.7)(syst)(-0.5)(+0.6)(lumi) pb. Using l tau events only, we measure: sigma(t (t) over bar) x B(t (t) over bar -> l tau b (b) over bar) = 0.13(-0.08)(+0.09)(stat)(-0.06)(+0.06)(syst)(-0.02)(+0.02)(lumi) pb. Comparing the measured cross section as a function of the mass of the top quark with a partial next-to-next-to leading order Quantum Chroniodynamics theoretical prediction, we extract a mass of the top quark of 171.5(-8.8)(+9-9) GeV, in agreement with direct measurements.
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| 41. |
- Abazov, M, et al.
(författare)
-
Measurement of the W Boson Mass
- 2009
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 103:14, s. 141801-
-
Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the W boson mass in W -> e nu decays using 1 fb(-1) of data collected with the D0 detector during Run II of the Fermilab Tevatron collider. With a sample of 499830 W -> e nu candidate events, we measure M-W=80.401 +/- 0.043 GeV. This is the most precise measurement from a single experiment.
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| 42. |
- Abazov, M, et al.
(författare)
-
Measurement of the WW Production Cross Section with Dilepton Final States in pp Collisions at s=1.96 TeV and Limits on Anomalous Trilinear Gauge Couplings
- 2009
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 103:19, s. 191801-
-
Tidskriftsartikel (refereegranskat)abstract
- We provide the most precise measurement of the WW production cross section in pp collisions to date at a center of mass energy of 1.96 TeV, and set limits on the associated trilinear gauge couplings. The WW -> l nu l(')nu (l, l(')=e, mu) decay channels are analyzed in 1 fb(-1) of data collected by the D0 detector at the Fermilab Tevatron Collider. The measured cross section is sigma(pp -> WW)=11.5 +/- 2.1(stat+syst)+/- 0.7(lumi) pb. One- and two-dimensional 95% C.L. limits on trilinear gauge couplings are provided.
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| 43. |
- Abazov, M, et al.
(författare)
-
Measurement of the Z gamma -> nu(nu)over-bar gamma Production Cross Section and Limits on Anomalous ZZ gamma and Z gamma gamma Couplings in p(p)over-bar Collisions at root s=1.96 TeV
- 2009
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:20, s. 201802-
-
Tidskriftsartikel (refereegranskat)abstract
- We present the first observation of the Z gamma -> nu(nu) over bar gamma process at the Fermilab Tevatron at 5.1 standard deviations significance, based on 3.6 fb(-1) of integrated luminosity collected with the D0 detector at the Fermilab Tevatron p (p) over bar Collider at root s = 1.96 TeV. The measured Z gamma production cross section multiplied by the branching fraction of Z -> nu(nu) over bar is 32 +/- 9(stat + syst) +/- 2(lumi) fb for the photon E-T > 90 GeV. It is in agreement with the standard model prediction of 39 +/- 4 fb. We set limits on anomalous trilinear Z gamma gamma and ZZ gamma gauge boson couplings, most of which are the most restrictive to date.
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| 44. |
- Abazov, M, et al.
(författare)
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Measurement of trilinear gauge boson couplings from WW plus WZ -> lvjj events in p(p)over-bar collisions at root s=1.96 TeV
- 2009
-
Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 80:5, s. 053012-
-
Tidskriftsartikel (refereegranskat)abstract
- We present a direct measurement of trilinear gauge boson couplings at gamma WW and ZWW vertices inWW and WZ events produced in p (p) over bar collisions at root s = 1:96 TeV. We consider events with one electron or muon, missing transverse energy, and at least two jets. The data were collected using the D0 detector and correspond to 1:1 fb(-1) of integrated luminosity. Considering two different relations between the couplings at the gamma WW and ZWW vertices, we measure these couplings at 68% C.L. to be kappa(gamma) = 1.07(-0.29)(+0.26) lambda = 0.00(-0.06)(+0.00), and g(1)(Z) = 1.04(-0.09)(+0.09) in a scenario respecting SU(2)(L) circle times U(1)(Y) gauge symmetry and kappa = 1.04(-0.11)(+0.11) and lambda = 0.00(-0.06)(+0.06) in an "equal couplings'' scenario.
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| 45. |
- Abazov, M, et al.
(författare)
-
Measurements of differential cross sections of Z/gamma* plus jets plus X events in p(p)over-bar collisions at root s=1.96 TeV
- 2009
-
Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 678:1, s. 45-54
-
Tidskriftsartikel (refereegranskat)abstract
- We present cross section measurements for Z/gamma* + jets + X production, differential in the transverse momenta of the three leading jets. The data sample was collected with the DO detector at the Fermilab Tevatron p (p) over bar collider at a center-of-mass energy of 1.96 TeV and corresponds to an integrated luminosity of 1 fb(-1). Leading and next-to-leading order perturbative QCD predictions are compared with the measurements. and agreement is found within the theoretical and experimental uncertainties. We also make comparisons with the predictions of four event generators. Two parton-shower-based generators show significant shape and normalization differences with respect to the data. In contrast, two generators combining tree-level matrix elements with a parton shower give a reasonable description of the shapes observed in data. but the predicted normalizations show significant differences with respect to the data, reflecting large scale Uncertainties. For specific choices of scales, the normalizations for either generator can be made to agree with the measurements.
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| 46. |
- Abazov, M, et al.
(författare)
-
Observation of Single Top-Quark Production
- 2009
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 103:9, s. 092001-
-
Tidskriftsartikel (refereegranskat)abstract
- We report observation of the electroweak production of single top quarks in pp collisions at s=1.96 TeV based on 2.3 fb(-1) of data collected by the D0 detector at the Fermilab Tevatron Collider. Using events containing an isolated electron or muon and missing transverse energy, together with jets originating from the fragmentation of b quarks, we measure a cross section of sigma(pp -> tb+X,tqb+X)=3.94 +/- 0.88 pb. The probability to measure a cross section at this value or higher in the absence of signal is 2.5x10(-7), corresponding to a 5.0 standard deviation significance for the observation.
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| 47. |
- Abazov, M, et al.
(författare)
-
Search for admixture of scalar top quarks in the t(t)over-bar lepton + jets final state at root s=1.96 TeV
- 2009
-
Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 674:1, s. 4-10
-
Tidskriftsartikel (refereegranskat)abstract
- A search for pair production of the lightest supersymmetric partner of the top quark, (t) over tilde (1), is performed in the lepton + jets channel using 0.9 fb(-1) of data collected by the D circle divide experiment. Kinematic differences between (t) over tilde (1)(t) over tilde (1) and the dominant top quark pair production background are used to separate the two processes. First limits from Run II of the Fermilab Tevatron Collider for the scalar top quark decaying to a chargino and a b quark ((t) over tilde1 -> (chi) over tilde (+)(1)b) are obtained for scalar top quark masses of 130-190 GeV and chargino masses of 90-150 GeV.
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| 48. |
- Abazov, M, et al.
(författare)
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Search for associated production of charginos and neutralinos in the trilepton final state using 2.3 fb(-1) of data
- 2009
-
Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 680:1, s. 34-43
-
Tidskriftsartikel (refereegranskat)abstract
- We report the results of a search for associated production of charginos and neutralinos using a data set corresponding to an integrated luminosity of 2.3 fb(-1) collected with the Demptyset experiment during Run II of the Tevatron proton-antiproton collider. Final states containing three charged leptons and missing transverse energy are probed for a signal from supersymmetry with four dedicated trilepton event selections. No evidence for a signal is observed, and we set limits on the product of production cross section and leptonic branching fraction. Within minimal supergravity, these limits translate into bounds on m(0) and m(1/2) that are well beyond existing limits.
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| 49. |
- Abazov, M, et al.
(författare)
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Search for Dark Photons from Supersymmetric Hidden Valleys
- 2009
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 103:8, s. 081802-
-
Tidskriftsartikel (refereegranskat)abstract
- We search for a new light gauge boson, a dark photon, with the D0 experiment. In the model we consider, supersymmetric partners are pair produced and cascade to the lightest neutralinos that can decay into the hidden sector state plus either a photon or a dark photon. The dark photon decays through its mixing with a photon into fermion pairs. We therefore investigate a previously unexplored final state that contains a photon, two spatially close leptons, and large missing transverse energy. We do not observe any evidence for dark photons and set a limit on their production.
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| 50. |
- Abazov, M, et al.
(författare)
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Search for Long-Lived Charged Massive Particles with the D0 Detector
- 2009
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:16, s. 161802-
-
Tidskriftsartikel (refereegranskat)abstract
- We search for long-lived charged massive particles using 1.1 fb(-1) of data collected by the D0 detector at the Fermilab Tevatron pp Collider. Time-of-flight information is used to search for pair produced long-lived tau sleptons, gauginolike charginos, and Higgsino-like charginos. We find no evidence of a signal and set 95% C.L. cross section upper limits for staus, which vary from 0.31 to 0.04 pb for stau masses between 60 and 300 GeV. We also set lower mass limits of 206 GeV (171 GeV) for pair produced charged gauginos (Higgsinos).
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