379 research outputs found

    Can contrast-enhanced MR imaging predict survival in breast cancer?

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    PURPOSE: To investigate the value of pre-operative contrast-enhanced MR imaging (CE-MRI) in predicting the disease-free and overall survival in breast cancer. MATERIAL AND METHODS: The study population consisted of 50 consecutive patients with histopathologically verified primary breast cancer who pre-operatively underwent CE-MRI examination between 1992 and 1993. A three-time point MR examination was performed where the enhancement rates (C1 and C2), signal enhancement ratio (SER=C1/C2) and washout (W=C1-C2) were calculated. The relation of these MR parameters to disease-free and overall survival was investigated. The median follow-up for surviving patients was 95 months. Univariate and multivariate statistical analyses were performed to evaluate the impact of different factors on prediction of survival. RESULTS: Of the MR parameters examined at univariate analysis, increased C1 (p=0.029), W (p=0.0081) and SER values (p=0.0081) were significantly associated with shorter disease-free survival, and only C1 (p=0.016) was related significantly to overall survival. Multivariate analysis for disease-free survival showed that the SER (p=0.014) and tumor size (p=0.001) were significant and independent predictors. Age (p=0.003), lymph node status (p=0.014), tumor size (p=0.039) and proliferating cell nuclear antigen index (p=0.053) remained independently associated with overall survival at multivariate analysis. C1 was not confirmed as an independent predictor of overall survival. CONCLUSION: Our findings support the presumption that CE-MRI is useful in predicting the disease-free survival in patients with breast cancer

    Slow dynamics near glass transitions in thin polymer films

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    The α\alpha-process (segmental motion) of thin polystyrene films supported on glass substrate has been investigated in a wider frequency range from 103^{-3} Hz to 104^4 Hz using dielectric relaxation spectroscopy and thermal expansion spectroscopy. The relaxation rate of the α\alpha-process increases with decreasing film thickness at a given temperature above the glass transition. This increase in the relaxation rate with decreasing film thickness is much more enhanced near the glass transition temperature. The glass transition temperature determined as the temperature at which the relaxation time of the α\alpha-process becomes a macroscopic time scale shows a distinct molecular weight dependence. It is also found that the Vogel temperature has the thickness dependence, i.e., the Vogel temperature decreases with decreasing film thickness. The expansion coefficient of the free volume αf\alpha_f is extracted from the temperature dependence of the relaxation time within the free volume theory. The fragility index mm is also evaluated as a function of thickness. Both αf\alpha_f and mm are found to decrease with decreasing film thickness.Comment: 9 pages, 7 figures, and 2 table

    Secondary Prevention Through Cardiac Rehabilitation: Position Paper of the Working Group on Cardiac Rehabilitation and Exercise Physiology of the European Society of Cardiology

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    The purpose of this statement is to provide specific recommendations in regard to evaluation and intervention in each of the core components of cardiac rehabilitation (CR) to assist CR staff in the design and development of their programmes; the statement should also assist health care providers, insurers, policy makers and consumers in the recognition of the comprehensive nature of such programmes. Those charged with responsibility for secondary prevention of cardiovascular disease, whether at European, at national or at individual centre level, need to consider where and how structured programmes of CR can be delivered to the large constituency of patients now considered eligible for C

    A radium assay technique using hydrous titanium oxide adsorbent for the Sudbury Neutrino Observatory

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    As photodisintegration of deuterons mimics the disintegration of deuterons by neutrinos, the accurate measurement of the radioactivity from thorium and uranium decay chains in the heavy water in the Sudbury Neutrino Observatory (SNO) is essential for the determination of the total solar neutrino flux. A radium assay technique of the required sensitivity is described that uses hydrous titanium oxide adsorbent on a filtration membrane together with a beta-alpha delayed coincidence counting system. For a 200 tonne assay the detection limit for 232Th is a concentration of 3 x 10^(-16) g Th/g water and for 238U of 3 x 10^(-16) g U/g water. Results of assays of both the heavy and light water carried out during the first two years of data collection of SNO are presented.Comment: 12 pages, 4 figure

    Measurement of the solar 8B neutrino rate with a liquid scintillator target and 3 MeV energy threshold in the Borexino detector

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    We report the measurement of electron neutrino elastic scattering from 8B solar neutrinos with 3 MeV energy threshold by the Borexino detector in Gran Sasso (Italy). The rate of solar neutrino-induced electron scattering events above this energy in Borexino is 0.217 +- 0.038 (stat) +- 0.008 (syst) cpd/100 t, which corresponds to the equivalent unoscillated flux of (2.4 +- 0.4 (stat) +- 0.1 (syst))x10^6 cm^-2 s^-1, in good agreement with measurements from SNO and SuperKamiokaNDE. Assuming the 8B neutrino flux predicted by the high metallicity Standard Solar Model, the average 8B neutrino survival probability above 3 MeV is measured to be 0.29+-0.10. The survival probabilities for 7Be and 8B neutrinos as measured by Borexino differ by 1.9 sigma. These results are consistent with the prediction of the MSW-LMA solution of a transition in the solar electron neutrino survival probability between the low energy vacuum-driven and the high-energy matter-enhanced solar neutrino oscillation regimes.Comment: 10 pages, 8 figures, 6 table

    New results on solar neutrino fluxes from 192 days of Borexino data

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    We report the direct measurement of the ^7Be solar neutrino signal rate performed with the Borexino detector at the Laboratori Nazionali del Gran Sasso. The interaction rate of the 0.862 MeV ^7Be neutrinos is 49+-3(stat)+-4(syst) counts/(day * 100ton). The hypothesis of no oscillation for ^7Be solar neutrinos is inconsistent with our measurement at the 4sigma level. Our result is the first direct measurement of the survival probability for solar nu_e in the transition region between matter-enhanced and vacuum-driven oscillations. The measurement improves the experimental determination of the flux of ^7Be, pp, and CNO solar nu_e, and the limit on the magnetic moment of neutrinos
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