246 research outputs found
Test Methods for the Determination of Interlayer Properties in Laminated Glass
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
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
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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
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
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?
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
Biocompatible cellulose nanocrystal-based Trojan horse enables targeted delivery of nano-Au radiosensitizers to triple negative breast cancer cells
: A hybrid cellulose-based programmable nanoplatform for applications in precision radiation oncology is described. Here, sugar heads work as tumor targeting moieties and steer the precise delivery of radiosensitizers, i.e. gold nanoparticles (AuNPs) into triple negative breast cancer (TNBC) cells. This "Trojan horse" approach promotes a specific and massive accumulation of radiosensitizers in TNBC cells, thus avoiding the fast turnover of small-sized AuNPs and the need for high doses of AuNPs for treatment. Application of X-rays resulted in a significant increase of the therapeutic effect while delivering the same dose, showing the possibility to use roughly half dose of X-rays to obtain the same radiotoxicity effect. These data suggest that this hybrid nanoplatform acts as a promising tool for applications in enhancing cancer radiotherapy effects with lower doses of X-rays
Preliminary Evidence of the Differential Expression of Human Endogenous Retroviruses in Kawasaki Disease and SARS-CoV-2-Associated Multisystem Inflammatory Syndrome in Children
Multisystem inflammatory syndrome in children (MIS-C) is a postinfectious sequela of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with some clinical features overlapping with Kawasaki disease (KD). Our research group and others have highlighted that the spike protein of SARS-CoV-2 can trigger the activation of human endogenous retroviruses (HERVs), which in turn induces inflammatory and immune reactions, suggesting HERVs as contributing factors in COVID-19 immunopathology. With the aim to identify new factors involved in the processes underlying KD and MIS-C, we analysed the transcriptional levels of HERVs, HERV-related genes, and immune mediators in children during the acute and subacute phases compared with COVID-19 paediatric patients and healthy controls. The results showed higher levels of HERV-W, HERV-K, Syn-1, and ASCT-1/2 in KD, MIS-C, and COV patients, while higher levels of Syn-2 and MFSD2A were found only in MIS-C patients. Moreover, KD and MIS-C shared the dysregulation of several inflammatory and regulatory cytokines. Interestingly, in MIS-C patients, negative correlations have been found between HERV-W and IL-10 and between Syn-2 and IL-10, while positive correlations have been found between HERV-K and IL-10. In addition, HERV-W expression positively correlated with the C-reactive protein. This pilot study supports the role of HERVs in inflammatory diseases, suggesting their interplay with the immune system in this setting. The elevated expression of Syn-2 and MFSD2A seems to be a distinctive trait of MIS-C patients, allowing to distinguish them from KD ones. The understanding of pathological mechanisms can lead to the best available treatment for these two diseases, limiting complications and serious outcomes
Estimating adjusted prevalence ratio in clustered cross-sectional epidemiological data
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
A design–build–test cycle using modeling and experiments reveals interdependencies between upper glycolysis and xylose uptake in recombinant S. cerevisiae and improves predictive capabilities of large-scale kinetic models
Serum Albumin Is Inversely Associated With Portal Vein Thrombosis in Cirrhosis
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
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