6 research outputs found

    Determination of the geographical origin of green coffee beans using NIR spectroscopy and multivariate data analysis

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    In this work, near infrared (NIR) spectroscopy and multivariate data analysis were investigated as a fast and non disruptive method to classify green coffee beans on continents and countries bases. FT-NIR spectra of 191 coffee samples, origin from 2 continents and 9 countries, were acquired by two different laboratories. Laboratory-independent Partial Least Square-Discriminant Analysis and interval PIS-DA models were developed by following a hierarchical approach, i.e. considering at first the continent and then the country of origin as discrimination rule. The best continent-based classification model was able to identify correctly more than 98% in prediction, whereas 100% of them were correctly predicted by the best country-based classification model. The inter-laboratory reliability of the proposed method was confirmed by McNemar test, since no significant differences (P > 0.05) were found. Furthermore, a validation was performed predicting the spectral test set of a laboratory using the model developed by the other one

    A system biology approach to ionizing radiation response by mammalian cell lines

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    A key issue when analyzing the biological effects of ionizing radiation is the selection of the biological endpoints. In this study we evaluated the effects of X-rays and protons on membrane ionic currents, cell growth and stress response. The membrane ionic currents amplitude showed a significant nonlinear effects. Growth curves showed a significant dose dependent decrease in the proliferation rate. The fluorescence data suggest a trend in which superoxide intracellular concentration decreases at lower irradiation doses compared to control and higher doses. These results are consistent with a signal transduction pathway where the concentration of superoxide is controlled by type and dose of ionizing radiatio

    Early effects comparison of x rays delivered at high-dose-rate pulses by a plasma focus device and at low dose rate on human tumour cells

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    A comparative study has been performed on the effects of high-dose-rate (DR) X-ray beams produced by a plasma focus device (PFMA-3), to exploit its potential medical applications (e.g. radiotherapy), and low-DR X-ray beams produced by a conventional source (XRT). Experiments have been performed at 0.5 and 2 Gy doses on a human glioblastoma cell line (T98G). Cell proliferation rate and potassium outward currents (IK) have been investigated by time lapse imaging and patch clamp recordings. The results showed that PFMA-3 irradiation has a greater capability to reduce the proliferation rate activity with respect to XRT, while it does not affect IK of T98G cells at any of the dose levels tested. XRT irradiation significantly reduces the mean IK amplitude of T98G cells only at 0.5 Gy. This work confirms that the DR, and therefore the source of radiation, is crucial for the planning and optimisation of radiotherapy applications
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