Purpose: To identify MRI-based radiomics as prognostic factors in patients with advanced nasopharyngeal carcinoma (NPC).Experimental Design: One-hundred and eighteen patients (training cohort: n ¼ 88; validation cohort: n ¼ 30) with advanced NPC were enrolled. A total of 970 radiomics features were extracted from T2-weighted (T2-w) and contrast-enhanced T1-weighted (CET1-w) MRI. Least absolute shrinkage and selection operator (LASSO) regression was applied to select features for progression-free survival (PFS) nomograms. Nomogram discrimination and calibration were evaluated. Associations between radiomics features and clinical data were investigated using heatmaps.Results: The radiomics signatures were significantly associated with PFS. A radiomics signature derived from joint CET1-w and T2-w images showed better prognostic performance than signatures derived from CET1-w or T2-w images alone. One radiomics nomogram combined a radiomics signature from joint CET1-w and T2-w images with the TNM staging system. This nomogram showed a significant improvement over the TNM staging system in terms of evaluating PFS in the training cohort (C-index, 0.761 vs. 0.514; P < 2.68 Â 10 À9 ). Another radiomics nomogram integrated the radiomics signature with all clinical data, and thereby outperformed a nomogram based on clinical data alone (C-index, 0.776 vs. 0.649; P < 1.60 Â 10 À7 ). Calibration curves showed good agreement. Findings were confirmed in the validation cohort. Heatmaps revealed associations between radiomics features and tumor stages. Conclusions: Multiparametric MRI-based radiomics nomograms provided improved prognostic ability in advanced NPC. These results provide an illustrative example of precision medicine and may affect treatment strategies.

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Bioethanol is currently a significant gasoline additive and the major blend component of flex-fuel formulations. Ethanol is a high-octane fuel component, and vehicles designed to take advantage of higher octane fuel blends could operate at higher compression ratios than traditional gasoline engines, leading to improved performance and tank-to-wheel efficiency. There are significant uncertainties, however, regarding the mechanism for ethanol autoignition, especially at lower temperatures such as in the negative temperature coefficient (NTC) regime. We have studied an important chemical process in the autoignition and oxidation of ethanol, reaction of the alpha-hydroxyethyl radical with O2(3P), using first principles computational chemistry, variational transition state theory, and Rice-Ramsperger-Kassel-Marcus (RRKM)/master equation simulations. The alpha-hydroxyethyl + O2 association reaction is found to produce an activated alpha-hydroxy-ethylperoxy adduct with ca. 37 kcal mol(-1) of excess vibrational energy. This activated adduct predominantly proceeds to acetaldehyde + HO(2), with smaller quantities of the enol vinyl alcohol (ethenol), particularly at higher temperatures. The reaction to acetaldehyde + HO2 proceeds with such a low barrier that collision stabilization of C2O3H5 isomers is unimportant, even for high-pressure/low-temperature conditions. The short lifetimes of these radicals precludes the chain-branching addition of a second O2 molecule, responsible for NTC behavior in alkane autoignition. This result helps to explain why ignition delays for ethanol are longer than those for ethane, despite ethanol having a weaker C-C bond energy. Given its relative instability, it is also unlikely that the alpha-hydroxy-ethylperoxy radical acts as a major acetaldehyde sink in the atmosphere, as has been suggested.