891 research outputs found

    Combination of celecoxib with percutaneous radiotherapy in patients with localised prostate cancer – a phase I study

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    BACKGROUND: Current approaches for the improvement of bNED for prostate cancer patients treated with radiotherapy mainly focus on dose escalation. However molecularly targeted approaches may also turn out to be of value. In this regard cyclooxygenase (COX)-2 inhibitors have been shown to exert some anti-tumour activities in human prostate cancer in vivo and in vitro. Although in vitro data indicated that the combination of COX-2 inhibition and radiation was not associated with an increased toxicity, we performed a phase I trial using high dose celecoxib together with percutaneous radiation therapy. METHODS: In order to rule out any increases of more than 20% incidence for a given side effect level 22 patients were included in the trial. Celecoxib was given 400 mg twice daily with onset of the radiation treatment. Risk adapted radiation doses were between 70 and 74 Gy standard fractionation. RTOG based gastrointestinal (GI) and genitourinary (GU) acute toxicity scoring was performed weekly during radiation therapy, at six weeks after therapy and three month after completing radiation treatment. RESULTS: Generally no major increase in the level and incidence of side effects potentially caused by the combined treatment was observed. In two cases a generalised skin rash occurred which immediately resolved upon discontinuation of the drug. No grade 3 and 4 toxicity was seen. Maximal GI toxicity grade 1 and 2 was observed in 85% and 10%, respectively. In terms of GU toxicity 80 % of the patients experienced a grade 1 toxicity and 10 % had grade 2 symptoms. CONCLUSION: The combination of irradiation to the prostate with concurrent high dose celecoxib was not associated with an increased level of side effects

    Characterizing Triviality of the Exponent Lattice of A Polynomial through Galois and Galois-Like Groups

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    The problem of computing \emph{the exponent lattice} which consists of all the multiplicative relations between the roots of a univariate polynomial has drawn much attention in the field of computer algebra. As is known, almost all irreducible polynomials with integer coefficients have only trivial exponent lattices. However, the algorithms in the literature have difficulty in proving such triviality for a generic polynomial. In this paper, the relations between the Galois group (respectively, \emph{the Galois-like groups}) and the triviality of the exponent lattice of a polynomial are investigated. The \bbbq\emph{-trivial} pairs, which are at the heart of the relations between the Galois group and the triviality of the exponent lattice of a polynomial, are characterized. An effective algorithm is developed to recognize these pairs. Based on this, a new algorithm is designed to prove the triviality of the exponent lattice of a generic irreducible polynomial, which considerably improves a state-of-the-art algorithm of the same type when the polynomial degree becomes larger. In addition, the concept of the Galois-like groups of a polynomial is introduced. Some properties of the Galois-like groups are proved and, more importantly, a sufficient and necessary condition is given for a polynomial (which is not necessarily irreducible) to have trivial exponent lattice.Comment: 19 pages,2 figure

    When veiled silences speak: reflexivity, trouble and repair as methodological tools for interpreting the unspoken in discourse-based data

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    Researchers who have attempted to make sense of silence in data have generally considered literal silences or such things as laughter. We consider the analysis of veiled silences where participants speak, but their speaking serves as ‘noise’ that ‘veils’, or masks, their inability or unwillingness to talk about a (potentially sensitive) topic. Extending Lisa Mazzei’s ‘problematic of silence’ by using our performativity-performance analytical method, we propose the purposeful use of ‘unusual conversational moves’, the deployment of researcher reflexivity, and the analysis of trouble and repair as methods to expose taken-for-granted normative frameworks in veiled silences. We illustrate the potential of these research practices through reference to our study on men’s involvement in reproductive decision-making, in which participants demonstrated an inability to engage with the topic. The veiled silence that this produced, together with what was said, pointed to the operation of procreative heteronormativity

    The construction of identities in narratives about serious leisure occupations

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    Engagement in occupation contributes to the shaping of identity throughout the human life. The act of telling about such engagement involves interaction based on symbolic meaning; the speaker constructing an identity by conveying how the occupation is personally meaningful. This study explored meaning in narratives told by people who engage in serious leisure occupations. A total of 78 narratives were extracted from interviews with 17 people who invest considerable time and other resources into their leisure. Analysis focused on the content, structure and performance of each narrative in order to explore meaning. The meanings were organised into a framework based around three dimensions: the located self, the active self and the changing self. Each dimension has facets that the individual might emphasise, constructing a unique identity. The framework offers a structured basis for conceptualising how occupation contributes to the shaping of the internalised self and the socially situated identity

    Proton acceleration by irradiation of isolated spheres with an intense laser pulse

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    We report on experiments irradiating isolated plastic spheres with a peak laser intensity of 2-3 x 10(20) W cm(-2). With a laser focal spot size of 10 mu m full width half maximum (FWHM) the sphere diameter was varied between 520 nm and 19.3 mu m. Maximum proton energies of similar to 25 MeV are achieved for targets matching the focal spot size of 10 mu m in diameter or being slightly smaller. For smaller spheres the kinetic energy distributions of protons become nonmonotonic, indicating a change in the accelerating mechanism from ambipolar expansion towards a regime dominated by effects caused by Coulomb repulsion of ions. The energy conversion efficiency from laser energy to proton kinetic energy is optimized when the target diameter matches the laser focal spot size with efficiencies reaching the percent level. The change of proton acceleration efficiency with target size can be attributed to the reduced cross-sectional overlap of subfocus targets with the laser. Reported experimental observations are in line with 3D3V particle in cell simulations. They make use of well-defined targets and point out pathways for future applications and experiments.DFG via the Cluster of Excellence Munich-Centre for Advanced Photonics (MAP) Transregio SFB TR18NNSA DE-NA0002008Super-MUC pr48meIvo CermakCGC Instruments in design and realization of the Paul trap systemIMPRS-APSLMUexcellent Junior Research FundDAAD|ToIFEEuropean Union's Horizon research and innovation programme 633053Physic

    A performative-performance analytical approach: infusing Butlerian theory into the narrative-discursive method

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    Judith Butler’s theory of performativity provides gender theorists with a rich theoretical language for thinking about gender. Despite this, Butlerian theory is difficult to apply, as Butler does not provide guidance on actual analysis of language use in context. In order to address this limitation, we suggest carefully supplementing performativity with the notion of performance in a manner that allows for the inclusion of relational specificities and the mechanisms through which gender, and gender trouble, occur. To do this, we turn to current developments within discursive psychology and narrative theory. We extend the narrative-discursive method proposed by Taylor and colleagues, infusing it with Butlerian theory in order to fashion a dual analytical lens, which we call the performativity-performance approach. We provide a brief example of how the proposed analytical process may be implemented
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