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Highest Stability (highest + stability)
Selected AbstractsEffects of tocopherols and tocotrienols on the inhibition of autoxidation of conjugated linoleic acidEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 4 2010Soon-Nam Ko Abstract The effect of eight vitamin E homologues, i.e. ,-, ,-, ,-, and ,-tocopherol and ,-, ,-, ,, and ,-tocotrienol, on the inhibition of autoxidation of conjugated linoleic acid (CLA) were investigated. The oxidation was carried out in the dark for 21 days at 50,°C and monitored by peroxide values (PV) and TBA values. The levels of the individual vitamin E homologues in CLA during storage were determined by HPLC. ,-Tocopherol exhibited the highest antioxidant activity among the homologues tested in this study when the antioxidant activities of the individual homologues in CLA were compared by PV. The order of antioxidant activity of eight homologues was ,-tocopherol,>,,-tocopherol,=,,-tocotrienol , ,-tocotrienol,>,,-tocopherol,=,,-tocotrienol,>,,-tocopherol,=,,-tocotrienol. The degradation rates of , -tocopherol and , -tocotrienol were faster than those of the other homologues, whereas ,-tocopherol had the highest stability in CLA during storage. All homologues exhibited an antioxidant activity by inhibiting the formation of secondary oxidation products. It appears that ,-tocotrienol and ,-tocotrienol have significantly higher antioxidant activities for secondary oxidation in CLA than ,-tocopherol and ,-tocopherol. Meanwhile, the other homologues, namely ,-tocopherol, ,-tocotrienol, ,-tocopherol, and ,-tocotrienol, exhibited similar antioxidant activity for secondary oxidation in CLA. [source] Evaluation of automated brain MR image segmentation and volumetry methodsHUMAN BRAIN MAPPING, Issue 4 2009Frederick Klauschen Abstract We compare three widely used brain volumetry methods available in the software packages FSL, SPM5, and FreeSurfer and evaluate their performance using simulated and real MR brain data sets. We analyze the accuracy of gray and white matter volume measurements and their robustness against changes of image quality using the BrainWeb MRI database. These images are based on "gold-standard" reference brain templates. This allows us to assess between- (same data set, different method) and also within-segmenter (same method, variation of image quality) comparability, for both of which we find pronounced variations in segmentation results for gray and white matter volumes. The calculated volumes deviate up to >10% from the reference values for gray and white matter depending on method and image quality. Sensitivity is best for SPM5, volumetric accuracy for gray and white matter was similar in SPM5 and FSL and better than in FreeSurfer. FSL showed the highest stability for white (<5%), FreeSurfer (6.2%) for gray matter for constant image quality BrainWeb data. Between-segmenter comparisons show discrepancies of up to >20% for the simulated data and 24% on average for the real data sets, whereas within-method performance analysis uncovered volume differences of up to >15%. Since the discrepancies between results reach the same order of magnitude as volume changes observed in disease, these effects limit the usability of the segmentation methods for following volume changes in individual patients over time and should be taken into account during the planning and analysis of brain volume studies. Hum Brain Mapp, 2009. © 2008 Wiley-Liss, Inc. [source] Computer Simulation of Dissociative Adsorption of Water on the Surfaces of Spinel MgAl2O4JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 7 2001Chang Ming Fang Atomistic simulation techniques have been used to model the dissociative adsorption of water onto the low-index {100}, {110}, and {111} surfaces of spinel MgAl2O4. The Born model of solids and the shell model for oxygen polarization have been used. The resulting structures and chemical bonding on the clean and hydrated surfaces are described. The calculations show that the dissociative adsorption of water on the low-index surfaces is generally energetically favorable. For the {110} and {111} orientations, the surfaces cleaved between oxygen layers show high absorption and stability. The calculations also show that, for the {111} orientation, the surfaces may absorb chemically water molecules up to ,90% coverage and have the highest stability. It is suggested that, during fracture, only partial hydration occurs, leading to cleavage preferentially along the {100} orientation. [source] A prospective study on the persistence of infant crying, sleeping and feeding problems and preschool behaviourACTA PAEDIATRICA, Issue 2 2010G Schmid Abstract Aim:, To determine the persistence of regulatory problems (RP), i.e. excessive crying (>3 months of age), feeding and sleeping difficulties from infancy to preschool age, and to evaluate whether RP at 5 months are predictive of preschool adaptive behaviour and social skills. Method:, A prospective population study of newborns admitted to neonatal care. RP at 5, 20 and 56 months of age were obtained via parent interviews and neurological examination and preschool adaptive behaviour and social skills by parent ratings. Logistic and linear regression analyses were conducted and controlled for psychosocial and neurological factors. Results:, More than half of the sample had RP at least at one measurement point. In about 8% of infants, RP persisted across the preschool years. Multiple RP and feeding problems increased the odds of eating problems at 20 and 56 months. Persistent RP and feeding problems were predictive of deficits in preschool adaptive behaviour and social skills. In addition, sex differences were found. Conclusions:, Multiple RP and feeding problems had the highest stability. Persistent RP were predictive of adverse social and adaptive behaviour. Understanding of the aetiology may help to prevent persistent RP [source] | ||||||||||