241 research outputs found

    Test Methods for the Determination of Interlayer Properties in Laminated Glass

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    Current standards introduce different test methods to be used for the determination of the dynamic properties of polymers. Some of these have been applied in the last years for the evaluation of the thermoviscoelastic properties of interlayer in laminated glass. Even the latest draft standards, which provide test methods for the determination of mechanical properties of laminated glass interlayers, hesitate in providing a definite test procedure and thus allow the use of three different test methods depending on the kind of interlayer. Here, a short review of the test methods collected from the literature is proposed and some considerations are made regarding their strengths and weaknesses. The scope of studies surveyed does not claim to be exhaustive, but simply to be representative of the variety of procedures employed in research. The necessity is stressed to converge to as limited a number of test methods as possible that are also adequately simple and can therefore be applied in most research laboratorie

    Dynamics and relaxation in new florinated side-chain polymers: an ESR investigation

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    Fluorinated azobenzene liquid crystalline polymers appear promising materials as optical data storage substrates, especially in holographic recording, for their ability of suppressing surface relief (1). Their applicative importance also arises from the excellent water repellency (2) and the possibility of modulating wettability by the change in the dipole moment of the cis-trans photochromic species (3). The comprehension of the mechanism by which the internal structure and molecular architecture of these materials affect their microscopic relaxation phenomena will address an ever improved design for technological applications and a fundamental understanding, enlightening the presence of cooperative mechanisms or/and dynamic heterogeneity. A new series of fluorinated homopolymers and random copolymers were investigated. They share the same main chain, and differentiate from a previous series (4, 5) for the substitution of the −(2)43 group with the −3 one in the terminal part of the azobenzene-containing side chain. The study was carried out by electron spin resonance to investigate the dynamics and matrix heterogeneity of the new series of copolymers, also in comparison with the previous non-fluorinated series. The structural relaxation of the polymers was also investigated by rheological measurements. Different molecular architectures result in modulation of the relaxation properties at nanoscale level. Dynamics and matrix heterogeneity is discussed, highlighting how the different molecular architecture affects different dynamic responses and matrix heterogeneity over different length and time scales. Information on cooperativity of the dynamics is also provided. References 1. F. You, M.Y.Paik, M. Häckel, L. Kador, D. Kropp, H.W. Schmidt, and C.K.Ober. Adv. Funct. Mater., 16: 1577, 2006. 2. S.D. Xiong, X.L. Guo, L. Li, S.l. Wu, P.K. Chu, and Z.S. Xu. J. Fluorine Chem., 131: 417, 2010. 3. K.Ichimura, S.K.Oh, and M.Nakagawa. Science, 288 (5471): 1624, 2000. ; S.Abbott, J.Ralston, G.Reynold, and R.Hayes. Langmuir, 15: 8923, 1999; L. M. Siewierski, W. J.Brittain, S.Petrash, and M.D.Foster. Langmuir, 12: 5838, 1996. 4. L. Andreozzi, M. Faetti, M. Giordano, D. Palazzuoli, and G. Galli. Macromolecules, 34: 7325, 2001. 5. L. Andreozzi, G. Galli, M. Giordano, E. Martinelli, and F. Zulli Macromolecules, 48: 6541, 201

    Emotional impact in β-thalassaemia major children following cognitive-behavioural family therapy and quality of life of caregiving mothers

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    Cognitive-Behavioural Family Therapy (CBFT) can be an effective psychological approach for children with beta-thalassaemia major, increasing compliance to treatment, lessening the emotional burden of disease, and improving the quality of life of caregivers

    Treatment of saline produced water through photocatalysis using rGO-TiO 2 nanocomposites

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    Graphene like-TiO2 nanocomposites (rGO-TiO2) are prepared via hydrothermal route by following different synthetic protocols. The as-prepared nanostructured materials exhibit higher photocatalytic activity than bare TiO2 in the treatment of synthetic produced water containing high salinity levels and different compositions of recalcitrant dissolved organic matter. The effect of the preparation method on the physico-chemical properties is assessed by performing a wide characterization combining different analyses, such as nitrogen physic-adsorption (BET), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), UV-VIS Diffuse Reflectance Spectroscopy (DRUV) and Electron Paramagnetic Resonance (EPR). The effect of several operative variables (i.e., TiO2/rGO weight ratios, and addition of hydrogen peroxide) on the photocatalytic activity is also critically evaluated. The highest photocatalytic activity is obtained for a rGO/TiO2 weight ratio of about 10%, for which a good compromise between uniformity of dispersion of the TiO2 particles on the rGO layers and covering degree of the titania photoactive surface is achieved. This study can contribute to open new perspectives in the design of high performance graphene like-based TiO2 photocatalysts for removing hydrophobic bio-recalcitrant pollutants from saline water.Peer ReviewedPostprint (author's final draft

    Gluten deprivation: What nutritional changes are found during the first year in newly diagnosed coeliac children?

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    Aim: A gluten-free diet (GFD) can expose children to excessive calories and fat intake. The study is intended to verify whether and how food intake, laboratory parameters, and growth are modified by a year of GFD. Methods: In 79 CD (coeliac disease) children (mean age 7.9 \ub1 3.8 years, 52 females, 27 males) diagnosed over 24 months, 24-h food diaries, food-frequency patterns, anthropometric and laboratory parameters (mainly blood sugar, insulin, lipid profile, and homocysteine) were prospectively collected before and during the first year of GFD. Nutrient intakes were compared over time and with recommendations. They were also used as regressors to explain the levels and changes of metabolic and growth variables. p-values < 0.05 were considered statistically significant. Results: Average macronutrient intake did not change during the year. Caloric intake remained below 90% (p 64 0.0001) and protein intake above 200% (p 64 0.0001) of recommendations. Lipid intake was stable at 34% of overall energy intake. Unsaturated fats increased (less omega-6 and more omega-3 with a ratio improvement from 13.3 \ub1 5.5 to 8.8 \ub1 3.1) and so did fibers, while folate decreased. The children who experienced a containment in their caloric intake during the year, presented a slower catch-up growth. Some differences were found across gender and age groups. In particular, adolescents consumed less calories, and females more omega-3. Fiber and simple sugar intakes emerged as implicated in lipid profile shift: fibers negatively with triglycerides (TG) (p = 0.033), simple sugars negatively with high-density lipoprotein (HDL) (p = 0.056) and positively with TG (p = 0.004). Waist-to-height ratio was positively associated with homocysteine (p = 0.018) and Homeostasis Model Assessment (p = 0.001), negatively with fibers (p = 0.004). Conclusion: In the short run, GFD is nutritionally very similar to any diet with gluten, with some improvements in unsaturated fats and fiber intake. Along with simple sugars containment, this may offer CD patients the opportunity for a fresh start. Caloric intakes may shift and should be monitored, especially in adolescents

    Estimating adjusted prevalence ratio in clustered cross-sectional epidemiological data

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    BACKGROUND: Many epidemiologic studies report the odds ratio as a measure of association for cross-sectional studies with common outcomes. In such cases, the prevalence ratios may not be inferred from the estimated odds ratios. This paper overviews the most commonly used procedures to obtain adjusted prevalence ratios and extends the discussion to the analysis of clustered cross-sectional studies. METHODS: Prevalence ratios(PR) were estimated using logistic models with random effects. Their 95% confidence intervals were obtained using delta method and clustered bootstrap. The performance of these approaches was evaluated through simulation studies. Using data from two studies with health-related outcomes in children, we discuss the interpretation of the measures of association and their implications. RESULTS: The results from data analysis highlighted major differences between estimated OR and PR. Results from simulation studies indicate an improved performance of delta method compared to bootstrap when there are small number of clusters. CONCLUSION: We recommend the use of logistic model with random effects for analysis of clustered data. The choice of method to estimate confidence intervals for PR (delta or bootstrap method) should be based on study design

    Serum Albumin Is Inversely Associated With Portal Vein Thrombosis in Cirrhosis

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    We analyzed whether serum albumin is independently associated with portal vein thrombosis (PVT) in liver cirrhosis (LC) and if a biologic plausibility exists. This study was divided into three parts. In part 1 (retrospective analysis), 753 consecutive patients with LC with ultrasound-detected PVT were retrospectively analyzed. In part 2, 112 patients with LC and 56 matched controls were entered in the cross-sectional study. In part 3, 5 patients with cirrhosis were entered in the in vivo study and 4 healthy subjects (HSs) were entered in the in vitro study to explore if albumin may affect platelet activation by modulating oxidative stress. In the 753 patients with LC, the prevalence of PVT was 16.7%; logistic analysis showed that only age (odds ratio [OR], 1.024; P = 0.012) and serum albumin (OR, -0.422; P = 0.0001) significantly predicted patients with PVT. Analyzing the 112 patients with LC and controls, soluble clusters of differentiation (CD)40-ligand (P = 0.0238), soluble Nox2-derived peptide (sNox2-dp; P < 0.0001), and urinary excretion of isoprostanes (P = 0.0078) were higher in patients with LC. In LC, albumin was correlated with sCD4OL (Spearman's rank correlation coefficient [r(s)], -0.33; P < 0.001), sNox2-dp (r(s), -0.57; P < 0.0001), and urinary excretion of isoprostanes (r(s), -0.48; P < 0.0001) levels. The in vivo study showed a progressive decrease in platelet aggregation, sNox2-dp, and urinary 8-iso prostaglandin F2 alpha-III formation 2 hours and 3 days after albumin infusion. Finally, platelet aggregation, sNox2-dp, and isoprostane formation significantly decreased in platelets from HSs incubated with scalar concentrations of albumin. Conclusion: Low serum albumin in LC is associated with PVT, suggesting that albumin could be a modulator of the hemostatic system through interference with mechanisms regulating platelet activation

    Prescription appropriateness of anti-diabetes drugs in elderly patients hospitalized in a clinical setting: evidence from the REPOSI Register

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    Diabetes is an increasing global health burden with the highest prevalence (24.0%) observed in elderly people. Older diabetic adults have a greater risk of hospitalization and several geriatric syndromes than older nondiabetic adults. For these conditions, special care is required in prescribing therapies including anti- diabetes drugs. Aim of this study was to evaluate the appropriateness and the adherence to safety recommendations in the prescriptions of glucose-lowering drugs in hospitalized elderly patients with diabetes. Data for this cross-sectional study were obtained from the REgistro POliterapie-Società Italiana Medicina Interna (REPOSI) that collected clinical information on patients aged ≥ 65 years acutely admitted to Italian internal medicine and geriatric non-intensive care units (ICU) from 2010 up to 2019. Prescription appropriateness was assessed according to the 2019 AGS Beers Criteria and anti-diabetes drug data sheets.Among 5349 patients, 1624 (30.3%) had diagnosis of type 2 diabetes. At admission, 37.7% of diabetic patients received treatment with metformin, 37.3% insulin therapy, 16.4% sulfonylureas, and 11.4% glinides. Surprisingly, only 3.1% of diabetic patients were treated with new classes of anti- diabetes drugs. According to prescription criteria, at admission 15.4% of patients treated with metformin and 2.6% with sulfonylureas received inappropriately these treatments. At discharge, the inappropriateness of metformin therapy decreased (10.2%, P < 0.0001). According to Beers criteria, the inappropriate prescriptions of sulfonylureas raised to 29% both at admission and at discharge. This study shows a poor adherence to current guidelines on diabetes management in hospitalized elderly people with a high prevalence of inappropriate use of sulfonylureas according to the Beers criteria
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