157 research outputs found
Nanostructured Lead Electrodes with Reduced Graphene Oxide for High-Performance LeadâAcid Batteries
Nanostructured Pb electrodes consisting of nanowire arrays were obtained by electrodeposition, to be used as negative electrodes for leadâacid batteries. Reduced graphene oxide was added to improve their performances. This was achieved via the electrochemical reduction of graphene oxide directly on the surface of nanowire arrays. The electrodes with and without reduced graphene oxide were tested in a 5 M sulfuric acid solution using a commercial pasted positive plate and an absorbed glass mat separator in a zero-gap configuration. The electrodes were tested in deep cycling conditions with a very low cut-off potential. Chargeâdischarge tests were performed at 5C. The electrode with reduced graphene oxide outperformed the electrode without reduced graphene oxide, as it was able to work with a very high utilization of active mass and efficiency. A specific capacity of 258 mAhgâ1âvery close to the theoretical oneâwas achieved, and the electrode lasted for more than 1000 cycles. On the other hand, the electrode without reduced graphene oxide achieved a capacity close to 230 mAhgâ1, which corresponds to a 90% of utilization of active mass
Behavior of a forest of NiFe nanowires in KOH and NaCl solution for water electrolysis
The present work investigates the behavior of nanostructured electrodes consisting of an array of nanowires of NiFe alloy in KOH + 0.5 M NaCl solution. The aim is to explore the possibility of using these electrodes for hydrogen production by seawater electrolysis. Seawater splitting requires a highly selective electrode on the anode side, where the evolution of molecular chlorine or the formation of other active chlorine compounds can compete with the oxygen evolution reaction. Nanostructured electrodes, obtained by template electrosynthesis, were tested at room temperature in KOH + 0.5 M NaCl solution, and the results were compared with those obtained in pure KOH. The results showed that the presence of NaCl does not affect the electrocatalytic behavior of the nanostructured NiFe alloy. Furthermore, the chemicalâphysical characterizations carried out after the long-term galvanostatic tests, have shown that the nanostructured electrodes are also stable in terms of morphology and composition. In addition, the solution used to perform the long-term galvanostatic tests was analyzed to investigate the possible formation of chlorine compounds. The absence of these compounds, together with the measured potential value measured for the oxygen evolution reaction, which was always lower than the thermodynamic redox potential for the hypochlorite formation reaction, leads us to conclude that these electrodes are potentially suitable for seawater electrolysis
MiRNA-513a-5p inhibits progesterone receptor expression and constitutes a risk factor for breast cancer : The hOrmone and Diet in the ETiology of breast cancer prospective study
report was to investigate whether many years before the diagnosis of breast cancer miRNA expression is already disregulated. In order to test this hypothesis, we compared miRNAs extracted from leukocytes in healthy women who later developed breast cancer and in women who remain healthy during the whole 15-year follow-up time. Accordantly, we used a case-control study design nested in the hOrmone and Diet in the ETiology of breast cancer (ORDET) prospective cohort study addressing the possibility that miRNAs can serve as both early biomarkers and components of the hormonal etiological pathways leading to breast cancer development in premenopausal women. We compared leukocyte miRNA profiles of 191 incident premenopausal breast cancer cases and profiles of 191 women who remained healthy over a follow-up period of 20 years. The analysis identified 20 differentially expressed miRNAs in women candidate to develop breast cancer versus control women. The upregulated miRNAs, miR-513-a-5p, miR- 513b-5p and miR-513c-5p were among the most significantly deregulated miRNAs. In multivariate analysis, miR-513a-5p upregulation was directly and statistically significant associated with breast cancer risk (OR = 1.69; 95% CI 1.08-2.64; P = 0.0293). In addition, the upregulation of miR-513-a-5p displayed the strongest direct association with serum progesterone and testosterone levels. The experimental data corroborated the inhibitory function of miR-513a-5p on progesterone receptor expression confirming that progesterone receptor is a target of miR-513a-5p. The identification of upregulated miR-513a-5p with its oncogenic potential further validates the use of miRNAs as long-term biomarker of breast cancer risk
Determinants of enhanced thromboxane biosynthesis in renal transplantation
Background. Despite great improvement in patient and graft survival, the long-term morbidity and mortality in renal transplant recipients (RTRs) are still significant, with a high incidence of cardiovascular disease-related deaths. Methods. We investigated thromboxane (TXA2) biosynthesis and endothelial and coagulative activation in 65 patients who received a renal transplant. Results. The rate of TXA2 biosynthesis (urinary 11-dehydro-TXB2 excretion largely reflects platelet TXA2 production in vivo) was significantly (P < 0.0001) higher in RTRs than in healthy subjects. Plasma von Willebrand factor (vWF) and thrombin-antithrombin (TAT) complexes were significantly higher (P < 0.001) in RTRs compared with controls. Urinary 11-dehydro-TXB2 directly correlated with plasma vWF and cholesterol. We next examined the relative influence of cyclosporine A (CsA) on TXA2 biosynthesis and endothelial activation, comparing a group of RTRs not receiving CsA with an age- and sex-matched group of patients treated with CsA. Urinary excretion of 11-dehydro-TXB2 and plasma levels of vWF were significantly increased in RTRs who received CsA compared with those who did not. After an overall follow-up of 120 months, RTRs who experienced cardiovascular events had a higher frequency of abnormal plasma levels of vWF than patients who remained event free. Conclusion. Renal transplantation is associated with in vivo platelet activation highly related to endothelial activation. This is particularly evident in CsA-treated patients. Administration of drugs that are able to reduce or eliminate thromboxane-dependent platelet activation in vivo may be beneficial to reduce the risk of cardiovascular events in RTRs
A wireless sensor network-based approach to large-scale dimensional metrology
In many branches of industry, dimensional measurements have become an important part of the production cycle, in order to check product compliance with specifications. This task is not trivial especially when dealing with largescale dimensional measurements: the bigger the measurement dimensions are, the harder is to achieve high accuracies. Nowadays, the problem can be handled using many metrological systems, based on different technologies (e.g. optical, mechanical, electromagnetic). Each of these systems is more or less adequate, depending upon measuring conditions, user's experience and skill, or other factors such as time, cost, accuracy and portability. This article focuses on a new possible approach to large-scale dimensional metrology based on wireless sensor networks. Advantages and drawbacks of such approach are analysed and deeply discussed. Then, the article briefly presents a recent prototype system - the Mobile Spatial Coordinate-Measuring System (MScMS-II) - which has been developed at the Industrial Metrology and Quality Laboratory of DISPEA - Politecnico di Torino. The system seems to be suitable for performing dimensional measurements of large-size objects (sizes on the order of several meters). Owing to its distributed nature, the system - based on a wireless network of optical devices - is portable, fully scalable with respect to dimensions and shapes and easily adaptable to different working environments. Preliminary results of experimental tests, aimed at evaluating system performance as well as research perspectives for further improvements, are discusse
UFGM - 2006 Annual Report
INGV, SEZIONE DI CATANIAPublished2.6. TTC - Laboratorio di gravimetria, magnetismo ed elettromagnetismo in aree attiveope
Effectiveness of Physical Activity Interventions in Sedentary People during COVID-19 Lockdown: A Systematic Review of Randomized Controlled Trials
Background: The social restriction measures during the COVID-19 pandemic resulted in decreasing physical activity levels. We aimed to evaluate whether the interventions reported in randomized controlled trials (RCTs) assessing the effects of physical activity during the COVID-19 lockdown on people with sedentary behavior were effective. Methods: We searched several databases from their inception until 1 April 2023, including RCTs evaluating the effects of any physical activity intervention in increasing the physical activity level in people with sedentary behavior during COVID-19 confinement, based on evidence derived from intervention studies with a control group. Studies were excluded if they (i) did not include humans; (ii) did not include sufficient information regarding the interventions or regarding the outcomes of interest; (iii) did not have a control group. We used the Rayyan systematic review platform for the selection of the studies to include based on the title/abstract information. Results: Starting with 2461 records from the original literature search, and after reviewing them according to the latest PRISMA recommendations, 11 RCTs including a total of 1770 participants were available and were included in the systematic review. We found that most of the studies examined (73%) reported the beneficial effects of the proposed interventions on improving the physical activity, reducing the sedentary time, and positively contributing to the psychological well-being of the participants. Conclusions: The results of the present systematic review on RCTs of interventions to increase physical activity in sedentary people during the COVID-19 lockdown show the beneficial effects of diverse online-delivered strategies, which can be applied even after the pandemic in conditions in which access to in-person activities is not possible
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