DELAMINAZIONE INTERLAMINARE DI COMPOSITI CFRP AL VARIARE DELLE CONDIZIONI DI CURA DELLA MATRICE

In questo lavoro si è condotto uno studio sperimentale del comportamento a delaminazione interlaminare in Modo I di laminati compositi unidirezionali in fibra di carbonio e matrice epossidica (CFRP), al variare delle condizioni di cura della matrice. Tutti i sistemi analizzati hanno utilizzato lo stesso tessuto e lo stesso monomero epossidico DGEBA. Variando il processo di cura (cura termica o mediante radiazioni), gli agenti di cura (ammine o anidridi per i sistemi curati termicamente), e l’impiego di additivi tenacizzanti (es. il PES per i sistemi irradiati), è stato possibile controllare e modificare sia il grado di adesione fibra/matrice, che il grado di fragilità della matrice (monitorato attraverso il Fattore Critico di Intensificazione degli Sforzi KIC). Il lavoro quindi propone una analisi critica dei meccanismi di resistenza alla delaminazione controllati dalla tenacità della matrice e dalla resistenza dell’interfaccia fibra-matrice, mediante la determinazione delle Curve di Resistenza e dei valori di GIC di Innesco e di Propagazione ottenuti per i diversi sistemi presi in esame

Water diffusion and swelling stresses in highly crosslinked epoxy matrices

The present work investigates the swelling induced stresses arising in two epoxy systems during water uptake. The analysed systems are two epoxy resin based on DGEBA monomer and DGEBF monomer respectively, both fully cured by DDS amine. The systems achieve different cross-link density degrees, and are characterised by high glass transition temperatures ranging between 200 and 230 °C. Both epoxies have been conditioned in deionized water baths at two different temperatures (50 °C and 80 °C). A desorption process at room temperature in a dry airborne environment was performed after saturation. Dynamic Mechanical Thermal Analysis, carried out at the various stages of hydrothermal conditioning, has allowed to characterise the modifications occurring in the network structures during aging. Photoelastic Stress Analysis is adopted to monitor the evolution of stresses on rectangular beam samples during absorption and desorption of water. Correlation of water uptake, dynamic mechanical behaviour and transitory stress fields, has allowed to make some assumptions about the influence of the epoxy network on the swelling behaviour

Health literacy in Mediterranean general population

INTRODUCTION Health literacy refers to "the ability to obtain, process, and understand basic health information and access health services in order to make informed choices." In essence, being able to acquire, understand, and use information for one's own health. METHODS Observational study through the administration of a face-to-face questionnaire conducted between July and September 2020 on 260 individuals residing between Calabria and Sicily, aged between 18 and 89 years. Questions related to education, lifestyle (alcohol, smoking, and physical activity). Multiple-choice questions to assess health literacy and conceptual skills, ability to find information on health topics and services, use of preventive medicine especially vaccinations, and ability to make decisions about one's own health. RESULTS Of 260, 43% were male and 57% female. The most represented age group is between 50 and 59 years. Forty-eight percent of respondents had a high school diploma. 39% smoke and 32% habitually consume alcoholic beverages; only 40% engage in physical activity. Ten percent had a low level of health literacy, average 55%, adequate 35%. CONCLUSIONS Given the importance of adequate HL on health choices and on individual and public wellbeing, it is essential to expand the knowledge of the individual, through public and private information campaigns and with an increasing involvement of family physicians, who are fundamental in training and informing their patients

Correlates of calcaneal quantitative ultrasound parameters in patients with diabetes: the study on the assessment of determinants of muscle and bone strength abnormalities in diabetes

OBJECTIVE: Quantitative ultrasound (QUS) provides an estimate of bone mineral density (BMD) and also evaluates bone quality, which has been related to increased fracture risk in people with diabetes. This study aimed at assessing the correlates of calcaneal QUS parameters in diabetic subjects encompassing various degrees of micro and macrovascular complications and a wide-range of peripheral nerve function. METHODS: Four hundred consecutive diabetic patients were examined by QUS to obtain values of broadband ultrasound attenuation (BUA), the speed of sound (SOS), quantitative ultrasound index (QUI), and BMD. RESULTS: Among surrogate measures of complications, sensory and motor nerve amplitude and heart rate response to cough test and standing correlated with QUS parameters at univariate analysis, together with age, body mass index (BMI), waist circumference, lipid profile, and renal function. Multivariate analysis revealed that BUA, SOS, QUI, and BMD were independently associated with age, male gender, hemoglobin A1c, BMI (or fat, but not fat-free mass), and somatic and autonomic nerve function parameters. CONCLUSIONS: These data indicate that peripheral nerve dysfunction is associated with worse QUS parameters, possibly contributing to increased fracture risk in diabetes. The positive relation of QUS measures with adiposity needs further investigation. This trial is registered with ClinicalTrials.gov (NCT01600924)

Comparison between local and regional anesthesia in arteriovenous fistula creation.

PURPOSE: Assessment of the effectiveness of Brachial Plexus Block (BPB) via axillary approach compared to regional anesthesia for arteriovenous fistula surgery in patients affected by end-stage renal disease. METHODS: We compared forty patients randomly divided into two groups. Group A underwent BPB procedure with 15 mL ropivacaine 1% and 10 mL of saline (0.9% NaCl) via axillary approach. Group B received local anesthesia with lidocaine 2%. The forearm blood vessels were assessed by Doppler ultrasonography before and after the intervention. RESULTS: BPB performed on Group A was associated with a considerable venous dilation and a significant decrease (48.7%, P<.05) in pulsatility index (PI) measured by Doppler ultrasound. In Group B, PI and venous dilation remained unaltered in the postoperative phase. No complications such as thrombosis or occlusion were encountered among patients who underwent BPB. CONCLUSIONS: The axillary-approached BPB was more advantageous than local anesthesia. Its effectiveness was because of venous dilation and the decrease in the PI, consequent to the reduction in peripheral resistances and the increase in local blood flow, thus offering an ideal background for fistula creation and short-term patency

Anterior prostatic tumours are difficult to diagnose without MRI

It is often uncertain whether a repeat biopsy is necessary in patients with at least one previous negative prostate biopsy but persistent suspicion of prostate cancer. Here we present the use of multi-parametric magnetic resonance imaging (mp-MRI) to successfully detect and localize a prostate cancer and we suggest that MRI can be useful in optimising repeat biopsy procedures of the prostate in patients with clinically significant carcinoma

Liver eosinophilic infiltrate is a significant finding in patients with chronic hepatitis C.

Eosinophilic infiltrate of liver tissue is described in primary cholestatic diseases, hepatic allograft rejection and drug-induced liver injury, but its significance and its implications in chronic hepatitis C are unknown. The aim of this study was to investigate the clinical significance of eosinophilic liver infiltrate in patients with chronic hepatitis C. We retrospectively evaluated 147 patients with chronic hepatitis C. The presence of eosinophilic infiltrate was investigated in liver biopsies, and a numeric count of eosinophilic leucocytes in every portal tract was assessed. An eosinophilic infiltrate of liver tissue (≥3 cells evaluated in the portal/periportal spaces) was observed in 46 patients (31%), and patients who consumed drugs had an odds ratio (OR) of 4.02 (95% CI: 1.62-9.96) to have an eosinophilic infiltrate in liver biopsy. By logistic regression analysis, the presence of steatosis was independently associated with eosinophilic infiltrate (OR 5.86; 95% CI: 2.46-13.96) and homeostasis model assessment-score (OR 1.18; 95% CI: 1.00-1.39). Logistic regression analysis also showed that fibrosis staging ≥ 2 by Scheuer score was associated with grading &gt;1 by Scheuer score (OR 6.82; 95% CI 2.46-18.80) and eosinophilic infiltrate (OR 4.00; 95% CI 1.23-12.91). In conclusion, we observed that the eosinophilic infiltrate of liver tissue was significantly more frequent in patients who assumed drugs, and found a significant association between eosinophilic infiltrate, liver steatosis and liver fibrosis. These preliminary data could lead to a constant assumption of drugs as a co-factor of eosinophils-mediated liver injury in chronic hepatitis