255 research outputs found

    Vector chiral order in frustrated spin chains

    Get PDF
    By means of a numerical analysis using a non-Abelian symmetry realization of the density matrix renormalization group, we study the behavior of vector chirality correlations in isotropic frustrated chains of spin S=1 and S=1/2, subject to a strong external magnetic field. It is shown that the field induces a phase with spontaneously broken chiral symmetry, in line with earlier theoretical predictions. We present results on the field dependence of the order parameter and the critical exponents.Comment: 8 pages, 9 figure

    HSP90 is essential for Jak-STAT signaling in classical Hodgkin lymphoma cells

    Get PDF
    In classical Hodgkin lymphoma (cHL) chemotherapeutic regimens are associated with stagnant rates of secondary malignancies requiring the development of new therapeutic strategies. We and others have shown that permanently activated Signal Transducer and Activator of Transcription (STAT) molecules are essential for cHL cells. Recently an overexpression of heat-shock protein 90 (HSP90) in cHL cells has been shown and inhibition of HSP90 seems to affect cHL cell survival. Here we analysed the effects of HSP90 inhibition by geldanamycin derivative 17-AAG or RNA interference (RNAi) on aberrant Jak-STAT signaling in cHL cells. Treatment of cHL cell lines with 17-AAG led to reduced cell proliferation and a complete inhibition of STAT1, -3, -5 and -6 tyrosine phosphorylation probably as a result of reduced protein expression of Janus kinases (Jaks). RNAi-mediated inhibition of HSP90 showed similar effects on Jak-STAT signaling in L428 cHL cells. These results suggest a central role of HSP90 in permanently activated Jak-STAT signaling in cHL cells. Therapeutics targeting HSP90 may be a promising strategy in cHL and other cancer entities associated with deregulated Jak-STAT pathway activation

    Burkholderia cenocepacia ET12 strain activates TNFR1 signalling in cystic fibrosis airway epithelial cells

    Full text link
    Burkholderia cenocepacia is an important pulmonary pathogen in individuals with cystic fibrosis (CF). Infection is often associated with severe pulmonary inflammation, and some patients develop a fatal necrotizing pneumonia and sepsis (‘cepacia syndrome’). The mechanisms by which this species causes severe pulmonary inflammation are poorly understood. Here, we demonstrate that B. cenocepacia BC7, a potentially virulent representative of the epidemic ET12 lineage, binds to tumour necrosis factor receptor 1 (TNFR1) and activates TNFR1-related signalling pathway similar to TNF-α, a natural ligand for TNFR1. This interaction participates in stimulating a robust IL-8 production from CF airway epithelial cells. In contrast, BC45, a less virulent ET12 representative, and ATCC 25416, an environmental B. cepacia strain, do not bind to TNFR1 and stimulate only minimal IL-8 production from CF cells. Further, TNFR1 expression is increased in CF airway epithelial cells compared with non-CF cells. We also show that B. cenocepacia ET12 strain colocaizes with TNFR1 in vitro and in the lungs of CF patients who died due to infection with B. cenocepacia, ET12 strain. Together, these results suggest that interaction of B. cenocepacia , ET12 strain with TNFR1 may contribute to robust inflammatory responses elicited by this organism.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73011/1/j.1462-5822.2007.01029.x.pd

    Оценка конкурентоспособности организации

    Get PDF
    Цель работы: обозначить пути повышения конкурентоспособности предприятия-производителя электротехнической продукции ООО «СИБАР ГРУПП» В процессе исследования проводились: анализ финансово-хозяйственной деятельности, анализ ассортимента предприятия, выделены основные финансовые показатели деятельности предприятия, проведен анализ конкурентной среды предприятия В результате исследования выявлены слабые места предприятия, рекомендованы меры по повышению конкурентоспособности предприятия на рынке электротехнического оборудования Экономическая эффективность/значимость работы: исполнение рекомендаций для повышения конкурентоспособности В будущем планируется: дальнейшее повышение конкурентоспособности.A research object is LTD "SIBAR GROUP" plant of electrical engineering equipment. Aim of work : to designate the ways of increase of competitiveness of enterprise on the example of enterprise LTD "SIBAR GROUP". In the process of research conducted: analysis of financially-economic activity, analysis of assortment of enterprise, basic financial performance of enterprise indicators are distinguished, the analysis of competition environment of enterprise is conducted. As a result of research the weak points of enterprise are educed, measures are recommended on their strengthening. Basic structural, technological and operating descriptions. Economic efficiency/ is meaningfulness of work : execution of recommendations for the increase of competitiveness

    First measurement of the helicity asymmetry for γppπ0\gamma p\rightarrow p\pi^0 in the resonance region

    Full text link
    The first measurement of the helicity dependence of the photoproduction cross section of single neutral pions off protons is reported for photon energies from 600 to 2300\,MeV, covering nearly the full solid angle. The data are compared to predictions from the SAID, MAID, and BnGa partial wave analyses. Strikingly large differences between data and predictions are observed which are traced to differences in the helicity amplitudes of well known and established resonances. Precise values for the helicity amplitudes of several resonances are reported

    The polarization observables T, P, and H and their impact on γppπ0\gamma p \to p\pi^0 multipoles

    Full text link
    Data on the polarization observables T, P, and H for the reaction γppπ0\gamma p\to p\pi^0 are reported. Compared to earlier data from other experiments, our data are more precise and extend the covered range in energy and angle substantially. The results were extracted from azimuthal asymmetries measured using a transversely polarized target and linearly polarized photons. The data were taken at the Bonn electron stretcher accelerator ELSA with the CBELSA/TAPS detector. Within the Bonn-Gatchina partial wave analysis, the new polarization data lead to a significant narrowing of the error band for the multipoles for neutral-pion photoproduction

    The N(1520) 3/2- helicity amplitudes from an energy-independent multipole analysis based on new polarization data on photoproduction of neutral pions

    Full text link
    New data on the polarization observables T, P, and H for the reaction γppπ0\gamma p \to p\pi^0 are reported. The results are extracted from azimuthal asymmetries when a transversely polarized butanol target and a linearly polarized photon beam are used. The data were taken at the Bonn electron stretcher accelerator ELSA using the CBELSA/TAPS detector. These and earlier data are used to perform a truncated energy-independent partial wave analysis in sliced-energy bins. This energy-independent analysis is compared to the results from energy-dependent partial wave analyses
    corecore