91 research outputs found

    Reference Force Field and CDW Amplitude of Mixed-Valence Halogen-Bridged Pt Complexes

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    The spectroscopic effects of electron-phonon coupling in mixed-valence chlorine-bridged Pt chains complexes are investigated through a parallel infrared and Raman study of three compounds with decreasing Pt-Pt distance along the chain. The e-ph interaction is analyzed in terms of the Herzberg-Teller coupling scheme. We take into account the quadratic term and define a precise reference state. The force field relevant to this state is constructed, whereas the electronic structure is analyzed in terms of a simple phenomenological model, singling out a trimeric unit along the chain. In this way we are able to account for all the available optical data of the three compounds, and to estimate the relevant microscopic parameters, such as the e-ph coupling constants and the CDW amplitude.Comment: 10 pages, compressed postscript, 6 Tables and 5 Figures also in a compressed ps.Z file. Revision is in the submission format only (postscript instead of tex

    Recurrence and mortality according to Estrogen Receptor status for breast cancer patients undergoing conservative surgery. Ipsilateral breast tumour recurrence dynamics provides clues for tumour biology within the residual breast

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    BACKGROUND: The study was designed to determine how tumour hormone receptor status affects the subsequent pattern over time (dynamics) of breast cancer recurrence and death following conservative primary breast cancer resection. METHODS: Time span from primary resection until both first recurrence and death were considered among 2825 patients undergoing conservative surgery with or without breast radiotherapy. The hazard rates for ipsilateral breast tumour recurrence (IBTR), distant metastasis (DM) and mortality throughout 10 years of follow-up were assessed. RESULTS: DM dynamics displays the same bimodal pattern (first early peak at about 24 months, second late peak at the sixth-seventh year) for both estrogen receptor (ER) positive (P) and negative (N) tumours and for all local treatments and metastatic sites. The hazard rates for IBTR maintain the bimodal pattern for ERP and ERN tumours; however, each IBTR recurrence peak for ERP tumours is delayed in comparison to the corresponding timing of recurrence peaks for ERN tumours. Mortality dynamics is markedly different for ERP and ERN tumours with more early deaths among patients with ERN than among patients with ERP primary tumours. CONCLUSION: DM dynamics is not influenced by the extent of conservative primary tumour resection and is similar for both ER phenotypes across different metastatic sites, suggesting similar mechanisms for tumour development at distant sites despite apparently different microenvironments. The IBTR risk peak delay observed in ERP tumours is an exception to the common recurrence risk rhythm. This suggests that the microenvironment within the residual breast tissue may enforce more stringent constraints upon ERP breast tumour cell growth than other tissues, prolonging the latency of IBTR. This local environment is, however, apparently less constraining to ERN cells, as IBTR dynamics is similar to the corresponding recurrence dynamics among other distant tissue

    The Dual Face of HOF in High-Risk Organizations

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    International audienceHigh-risk organizations commonly acknowledge the importance of human and organizational factors (HOF). However, in practice the role played by HOF specialists and their share of voice varies dramatically from one organization to another. Within organizations themselves, there are some recurrent tensions around HOF and the role HOF specialists are understood to play. This delicate situation seems to partly stem from the gap between conventional wisdom on HOF in high-risk organizations and how HOF specialists see HOF and their role and contribution to organizations. Exploring this dual face of HOF and trying to better understand where it comes from may help to reduce misunderstandings and suggest ways forward to build on the remaining inevitable organizational contradictions to improve the way HOF are considered in high-risk industries
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