Solid particle erosion and viscoelastic properties of thermoplastic polyurethanes

The wear resistance of several thermoplastic polyurethanes (TPUs) having different chemical nature and micronscale arrangement of the hard and soft segments has been investigated by means of erosion and abrasion tests. The goal was correlating the erosion performances of the materials to their macroscopic mechanical properties. Unlike conventional tests, such as hardness and tensile measurements, viscoelastic analysis proved to be a valuable tool to study the erosion resistance of TPUs. In particular, a strict correlation was found between the erosion rate and the high-frequency (~10^7 Hz) loss modulus. The latter reflects the actual ability of TPU to dissipate the impact energy of the erodent particles

Self-esteem in physically active middle school students

The present research examined the effect of physical fitness on self-esteem of pre-adolescent children. Students performed the MOTORFIT tests and filled IPAQ-C and Self-Esteem questionnaires. According to the level of the physical fitness we evaluated the self-esteem. Results showed no gender differences, while differences for the level of physical fitness was found. In particular, participants who performed better the MOTORFIT test reported a higher self-esteem compared to less physical fit participants. However, a discrepancy emerged when the self-esteem was analysed as a function of the physical activity reported where no differences emerged between the groups. In conclusion, our results provided an effect of physical activity on self-esteem through objective measures. Key words: physical activity, pre-adolescent, psychosocial characteristics

Lipocalina e Delayed Graft Function nel paziente trapiantato renale

INTRODUZIONE: Il rene trapiantato è esposto agli effetti dell’ischemia-riperfusione responsabili di ritardata ripresa funzionale dell’organo (delayed graft function; DGF). DGF può incidere negativamente sull’evoluzione del rene trapiantato. Nel presente studio è stato valutato il ruolo della lipocalina urinaria quale predittore di DGF. MATERIALI E METODI: Sono stati valutati pazienti sottoposti a trapianto di rene da donatore cadavere. Prelievi ematici erano effettuati immediatamente prima del trapianto. Le urine erano raccolte per le 24 ore successive al trapianto. DGF era definita dalla necessità di trattamento dialitico entro la prima settimana dal trapianto. RISULTATI: Sono stati valutati 20 pazienti. I pazienti che avevano una rapida ripresa funzionale del rene trapiantato (NO-DGF) erano 14 (70%). DGF era osservata in 6 pazienti. L’età media nei DGF era superiore (58±6 Vs 51±11, p=0.001). Nei pazienti DGF risultavano significativamente ridotta la diuresi (57±35 Vs 4150 ± 2230 ml/24h; p=0.001) e la escrezione urinaria di creatinina (191±184 Vs 683±660 mg/24h; p=0.001), misurate nel primo giorno successivo al trapianto. Non erano osservate significative differenze tra pazienti DGF e NO-DGF per la escrezione urinaria di lipocalina (1,20±2,20 Vs 2,44±4,0 mg/24h; p<0.20). In univariata, DGF risultava associata negativamente alla diuresi (r2=-0.795, p=0.001) ed alla escrezione urinaria di creatinina (r2=-0.480, p=0.037) e positivamente all’età (r2=0.446, p=0.049). In multivariata diuresi (p=0.014) ed escrezione urinaria di creatinina (p=0.039) erano associati a DFG. CONCLUSIONI: Lipocalina urinaria, misurata nel giorno successivo al trapianto renale, non è biomarcatore predittivo di DGF. I risultati del presente studio possono essere stati influenzati dal campione limitato di pazienti e dalla bassa incidenza di DGF

Systematic design through the integration of TRIZ and optimization tools

AbstractMarketing strategies are focusing on innovation as the key for being competitive; as a consequence, product development processes must be improved in order to have a link as close as possible between conceptual design and detailed design activities. Within this context, TRIZ and TRIZ-based methodologies and tools are still poorly integrated with product embodiment means: CAD/CAE systems are not suited for supporting the designer in the conceptual design phase and at the same time inventive/separation principles, standard solutions etc. can hardly be translated into a modification of a CAD model and the only opportunity is to restart the modeling process.A small consortium of Italian Universities is analyzing the opportunity to use Design Optimization tools as a means for linking Computer-Aided Innovation (CAI) tools with Product Lifecycle Management (PLM) systems: www.kaemart.it/prosit. Among the specific objectives of the project, this paper describes how to analyze TRIZ technical contradictions by means of Design Optimization tools, with the aim of translating them into physical contradictions. The suggestions provided by inventive/separation principles are therefore converted into a new Design Optimization problem for the development of a novel solution

Advances in the genetics of hypertension: The effect of rare variants

Worldwide, hypertension still represents a serious health burden with nine million people dying as a consequence of hypertension-related complications. Essential hypertension is a complex trait supported by multifactorial genetic inheritance together with environmental factors. The heritability of blood pressure (BP) is estimated to be 30–50%. A great effort was made to find genetic variants affecting BP levels through Genome-Wide Association Studies (GWAS). This approach relies on the “common disease–common variant” hypothesis and led to the identification of multiple genetic variants which explain, in aggregate, only 2–3% of the genetic variance of hypertension. Part of the missing genetic information could be caused by variants too rare to be detected by GWAS. The use of exome chips and Next-Generation Sequencing facilitated the discovery of causative variants. Here, we report the advances in the detection of novel rare variants, genes, and/or pathways through the most promising approaches, and the recent statistical tests that have emerged to handle rare variants. We also discuss the need to further support rare novel variants with replication studies within larger consortia and with deeper functional studies to better understand how new genes might improve patient care and the stratification of the response to antihypertensive treatments

Analysis and modeling of swelling and erosion behavior for pure HPMC tablet

This work is focused on the transport phenomena which take place during immersion in water of pure hydroxypropylmethylcellulose tablets. The water uptake, the swelling and the erosion during immersion were investigated in drug-free systems, as a preliminary task before to undertake the study of drug-loaded ones. The tablets, obtained by powder compression, were confined between glass slabs to allow water uptake only by lateral surface and then immersed in distilled water at 37 °C, with simultaneous video-recording. By image analysis the normalized light intensity profiles were obtained and taken as a measure of the water mass fraction. The time evolutions of the total tablet mass, of the water mass and of the erosion radius were measured, too. Thus a novel method to measure polymer and water masses during hydration was pointed out. Then, a model consisting in the transient mass balance, accounting for water diffusion, diffusivity change due to hydration, swelling and erosion, was found able to reproduce all experimental data. Even if the model was already used in literature, the novelty of our approach is to compare model predictions with a complete set of experimental data, confirming that the main phenomena were correctly identified and described

Early impairment of endothelial structure and function in young normal-weight women with polycystic ovary syndrome

The aim of this study was to evaluate the presence of early vascular damage in young normal-weight women with polycystic ovary syndrome (PCOS).Thirty young normal-weight women with PCOS, who had no additional metabolic or cardiovascular diseases, and 30 healthy women (controls) matched for age and body mass index were studied. A complete hormonal assay was performed in each subject. Serum insulin and glucose levels were measured at baseline and after the oral glucose tolerance test. Plasma endothelin-1 levels and serum lipid profile were also assessed. The endothelial function was studied by flow-mediated dilation on the brachial artery, and arterial structure was evaluated by intima-media thickness measurement using Doppler ultrasound of both common carotid arteries.A significant (P &lt; 0.05) difference in flow-mediated dilation (14.3 +/- 1.9% vs. 18.1 +/- 2.0% for PCOS patients and controls, respectively) and in intima-media thickness (0.53 +/- 0.09 mm vs. 0.39 +/- 0.08 mm for PCOS patients and controls, respectively) was found between PCOS and control subjects. Serum endothelin-1 levels were also significantly (P &lt; 0.05) higher in PCOS patients compared with controls (1.1 +/- 0.4 pmol/liter vs. 0.5 +/- 0.2 pmol/liter for PCOS patients and controls, respectively).In conclusion, our data show that young, normal-weight, nondyslipidemic, nonhypertensive women with PCOS have an early impairment of endothelial structure and function

Removing the division into categories between cycling and para-cycling (Handbike category H) by designing a single performance and training activity

Cycling and all categories of para-cycling including Handbike are cyclical sports, that is, sports characterized using a specific skill, continuous skill. To separate competitions between cyclists and paracyclists, there is a classification system. The study in aims to design one activity performance and training, to eliminate the division into categories between cycling and para-cycling (Handbike), since this does not favour the integration and sporting inclusion of the two groups of athletes. The differences in performance will be identified between: cyclists and paracyclists with spinal cord injury or amputation of the lower limbs (H). Then will proceed to design and verify an activity capable of making the two categories compete and train together, eliminating the differences in performance through the use of a "counterweight" and using a mixed training, HIIT (High Intensity Interval Training) and Endurance. The sample taken into consideration is composed of 5 cyclists and 5 paracyclists (H) aged between 19 and 38 years. To achieve the goal, the study was based on the method of analysing the scientific literature, detecting the various parameters in the race and using mathematical statistical methods, such as Multiple Regression and the T-Test for independent samples. The analysis of the results of this study shows that; between cyclists and para-cyclists who participated, there are substantial differences in performance, thanks to the data obtained from multiple regression, in which we find an R-squared value that is .999975008, also the only positive coefficient among the independent variables is that of power (6.760634791). This means that of all the reported values, it is the only one that directly affects performance

Exploring public attitude toward biofeedback technologies: Knowledge, preferences and personality tendencies

Background: Biofeedback is increasingly used in the clinical area and in daily health monitoring through wearable devices (e.g. smart watches). Nevertheless, it remains rather unknown. This study aimed to assess, in a sample of Italian citizens, the level of knowledge, attitudes, perceived efficacy and personality tendencies which could affect the uptake of biofeedback technologies.&nbsp;Design and Methods: Participants were recruited by advertising the survey on the social networks, from March to May 2019. 160 subjects filled in an ad hoc online questionnaire assessing socio-demographic variables, clinical status, physical activity, knowledge and attitude towards biofeedback, psychological tendencies toward health.Results: Data showed a good level of interest in biofeedback training in spite of poor knowledge about such technologies. Sport and chronic diseases were not correlated to a greater use of biofeedback. People informed about biofeedback technologies were more interested in undergoing biofeedback training and had higher scores in the Health Locus of Control. Finally, people who showed a positive perception of their own health (Health Esteem) did not rely on these technologies.Discussion: Despite the huge spread of biofeedback technologies, our results disconfirmed the expectation that people having an active lifestyle or a disease were more familiar with biofeedback systems. The attitude toward such technologies seems to depend on individual tendencies.Conclusions: This study suggests the importance to improve general public literacy on biofeedback technologies, tailor tools on their needs and characteristics, empower people’s sense of internal health control for promoting a valid use and a proper knowledge of biofeedback