17 research outputs found

    Internal Oxidation of a Fe-Cr Binary Alloy at 700-900 degrees C: The Role of Hydrogen and Water Vapor

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    Internal oxidation of Fe-2.25Cr has been studied in Fe/FeO Rhines pack (RP) and H-2/H2O gas mixtures at 700-900 degrees C. A novel exposure technique allowing RP experiments in dual atmosphere conditions was developed. No measurable effect of hydrogen on lattice oxygen permeability in ferrite could be detected: neither in single nor in dual atmosphere conditions. The H-2/H2O atmosphere was found to induce stronger oxidation attack at alloy grain boundaries resulting in a morphology similar to intergranular stress corrosion cracking often reported in nuclear technology. The intergranular oxidation attack was demonstrated to be independent of the dual atmosphere effect, i.e., hydrogen dissolved in the alloy

    Effect of Hydrogen on the Internal Oxidation of a Pd–Cr Alloy in Dual-Atmosphere Conditions

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    The effect of hydrogen on oxygen permeability has been studied in a diluted Pd–Cr alloy in dual- and single- atmosphere conditions between 600 and 950\ua0\ub0C. The 0.3\ua0mm thick Pd–1.5Cr foil was exposed in dry and humid air as well as in dual-atmosphere conditions, with one sample surface being exposed to air and one to hydrogen, as encountered in solid oxide fuel cells. At all temperatures, Cr oxidized internally forming internal oxidation zones which were measured in metallographic cross sections. Below 800\ua0\ub0C, an external layer of PdO formed on the surface decreasing the internal oxidation kinetics. No measurable effect of hydrogen on the internal oxidation of Cr in Pd has been detected

    In vitro bioaccessibility of phenolic acids from a commercial aleurone-enriched bread compared to a whole grain bread

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    Wheat aleurone, due to its potentially higher bioaccessibility and bioavailability of micronutrients and phenolic acids, could represent a useful ingredient in the production of commonly consumed cereal-based food. The aim of the present study was to investigate the in vitro bioaccessibility of phenolic acids both from an aleurone-enriched bread and from a whole grain bread. The two bread samples were firstly characterized for the phenolic acid content. An in vitro digestion was then performed in order to evaluate the release of phenolic acids. The results obtained suggest that the bioaccessibility of the phenolic acids in the aleurone-enriched bread is higher than in the whole grain bread. These in vitro results suggest the potential use of aleurone in the production of foods, and this may represent an attractive possibility to vehicle nutritionally interesting components to consumers

    A model predicting primary infections of Plasmopara viticola in different grapevine-growing areas of Italy

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    A dynamic model for Plasmopara viticola primary infections was evaluated by comparing model predictions with disease onset in: i) 100 vineyards of Northern, Southern and Insular Italy (1995 to 2007); ii) 42 groups of potted grapevine plants exposed to inoculum (2006 to 2008). The model simulates the development of any oospore cohort during the primary inoculum season, including: oospore germination; production and survival of sporangia; release, survival and dispersal of zoospores; infection and incubation. The model showed high sensitivity, specificity, and accuracy both in vineyards and in potted plants. The true positive and negative proportions were TPP=0.99 and TNP=0.87, respectively. Because of a certain proportion of false positive predictions (FPP=0.13), confidence in prediction of non-infections was higher than in prediction of infections. These wrong predictions occurred in early season or when the oosporic inoculum was low, or were triggered by isolated weak rain events. In only one case (a group of potted plants) there was infection when infection was not predicted (FNP=0.005). Considering that: i) the data used for evaluation were not used in model development, ii) the grape-growing areas considered represent the different climatic zones of grape cultivation in Italy, iii) both early and late primary infections were observed in the vineyards, iv) both first seasonal and further infections were observed in the potted plants, v) neither calibration nor empirical adjustment of model parameters were necessary, the model can be considered an accurate and robust predictor of P. viticola oosporic infections

    Association of Apelin Levels in Overweight-obese Children with Pubertal Development, but Not with Insulin Sensitivity: 6.5 Years Follow up Evaluation

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    Background: Obesity in youth is associated with increased risk of metabolic disorders. Adipose tissue hormones are involved in body-weight regulation. Among these, apelin is recognized as an insulin-sensitizer adipokine. Data on apelin levels in obese children and its relation to insulinsensitivity are limited. Objective: We aimed to evaluate apelin levels in relation to obesity and insulin sensitivity in a large cohort of overweight/obese children and adolescents. Furthermore, these youths were reevaluated after a median 6.5 years of follow-up, thus allowing assessing changes in apelin levels in relation to increasing age and weight changes. Methods: Clinical data in 909 children and adolescents were collected between 2007 and 2010. Two hundred and one were reexamined at a median 6.5 years of follow-up. All subjects at baseline and at follow-up underwent an OGTT. Apelin levels were measured on sera by ELISA method. Results: At baseline, lower apelin levels were associated with increasing age and puberty (Tanner ≥II 0.67 ± 0.96 ng/mL vs. Tanner I 0.89 ± 1.13 ng/mL, p < .002), but not with body-weight. At followup, apelin levels in the 201 subjects reexamined were significantly lower than at baseline (0.45 ± 0.77 ng/mL at follow-up, 0.68 ± 0.95 ng/mL baseline, p < .001), confirming the effects of age and puberty. Body-weight did not affect apelin levels. Multiple regression analysis confirmed that sex and puberty were associated with lower apelin levels, independently from age and insulinsensitivity. Conclusions: Apelin levels decrease significantly with pubertal development, whilst body-weight in children and adolescents did not determine changes in apelin. Reduced levels of apelin in children and adolescents may therefore represent a necessary response to maintain the “physiological” insulin resistance of puberty

    "Delirium Day": A nationwide point prevalence study of delirium in older hospitalized patients using an easy standardized diagnostic tool

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    Background: To date, delirium prevalence in adult acute hospital populations has been estimated generally from pooled findings of single-center studies and/or among specific patient populations. Furthermore, the number of participants in these studies has not exceeded a few hundred. To overcome these limitations, we have determined, in a multicenter study, the prevalence of delirium over a single day among a large population of patients admitted to acute and rehabilitation hospital wards in Italy. Methods: This is a point prevalence study (called "Delirium Day") including 1867 older patients (aged 65 years or more) across 108 acute and 12 rehabilitation wards in Italian hospitals. Delirium was assessed on the same day in all patients using the 4AT, a validated and briefly administered tool which does not require training. We also collected data regarding motoric subtypes of delirium, functional and nutritional status, dementia, comorbidity, medications, feeding tubes, peripheral venous and urinary catheters, and physical restraints. Results: The mean sample age was 82.0 ± 7.5 years (58 % female). Overall, 429 patients (22.9 %) had delirium. Hypoactive was the commonest subtype (132/344 patients, 38.5 %), followed by mixed, hyperactive, and nonmotoric delirium. The prevalence was highest in Neurology (28.5 %) and Geriatrics (24.7 %), lowest in Rehabilitation (14.0 %), and intermediate in Orthopedic (20.6 %) and Internal Medicine wards (21.4 %). In a multivariable logistic regression, age (odds ratio [OR] 1.03, 95 % confidence interval [CI] 1.01-1.05), Activities of Daily Living dependence (OR 1.19, 95 % CI 1.12-1.27), dementia (OR 3.25, 95 % CI 2.41-4.38), malnutrition (OR 2.01, 95 % CI 1.29-3.14), and use of antipsychotics (OR 2.03, 95 % CI 1.45-2.82), feeding tubes (OR 2.51, 95 % CI 1.11-5.66), peripheral venous catheters (OR 1.41, 95 % CI 1.06-1.87), urinary catheters (OR 1.73, 95 % CI 1.30-2.29), and physical restraints (OR 1.84, 95 % CI 1.40-2.40) were associated with delirium. Admission to Neurology wards was also associated with delirium (OR 2.00, 95 % CI 1.29-3.14), while admission to other settings was not. Conclusions: Delirium occurred in more than one out of five patients in acute and rehabilitation hospital wards. Prevalence was highest in Neurology and lowest in Rehabilitation divisions. The "Delirium Day" project might become a useful method to assess delirium across hospital settings and a benchmarking platform for future surveys

    The instruments used by the Italian centres for cognitive disorders and dementia to diagnose mild cognitive impairment (MCI)

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    Aims: The purpose of this study was to examine the tools used in Italy to diagnose mild cognitive impairment (MCI). Methods: In collaboration with the Luigi Amaducci Research Consortium, the Italian Network of Alzheimer Evaluation Units prepared a questionnaire to describe how MCI is diagnosed in the Italian Centres for cognitive disorders and dementia (CCDD). Results: Most of the ninety-two CCDDs participating in the survey were located in hospitals (54.7%); large percentages were coordinated by neurologists (50.8%) and geriatricians (44.6%). Almost all (98.5%) used the Mini Mental State Examination to diagnose MCI; the Clock Drawing Test was also frequently used (83.9%). Other neuropsychological, imaging and biomarker tests were utilized less frequently and a wide diversity in the instruments used was noted. Conclusions: According to the results, diagnoses of MCI are based on a multitude of instruments, with major differences in the clinical assessment of geriatricians and neurologists. Standardized testing protocols, validated instruments and cut-off points need to be identified and adopted by the CCDDs for assessing MCI
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