4 resultados para Wireless electrochemical promotion of catalysis
em AMS Tesi di Dottorato - Alm@DL - Università di Bologna
Resumo:
High serum levels of Interleukin-6 (IL-6) correlate with poor outcome in breast cancer patients. However no data are available on the relationship between IL-6 and stem/progenitor cells which may fuel the genesis of breast cancer in vivo. Herein, we address this issue in mammospheres (MS), multi-cellular structures enriched in stem/progenitor cells of the mammary gland, and also in MCF-7 breast cancer cells. We show that MS from node invasive breast carcinoma tissues express IL-6 mRNA at higher levels than MS from matched non-neoplastic mammary glands. We find that IL-6 mRNA is detectable only in basal-like breast carcinoma tissues, an aggressive variant showing stem cell features. Our results reveal that IL-6 triggers a Notch-3-dependent up-regulation of the Notch ligand Jagged-1, whose interaction with Notch-3 promotes the growth of MS and MCF-7 derived spheroids. Moreover, IL-6 induces a Notch-3-dependent up-regulation of the carbonic anhydrase IX gene, which promotes a hypoxia-resistant/invasive phenotype in MCF-7 cells and MS. Finally, an autocrine IL-6 loop relies upon Notch-3 activity to sustain the aggressive features of MCF-7-derived hypoxia-selected cells. In conclusion, our data support the hypothesis that IL-6 induces malignant features in Notch-3 expressing, stem/progenitor cells from human ductal breast carcinoma and normal mammary gland.
Resumo:
Cancer is one of the principal causes of death in the world; almost 8.2 million of deaths were counted in 2012. Emerging evidences indicate that most of the tumors have an increased glycolytic rate and a detriment of oxidative phosphorylation to support abnormal cell proliferation; this phenomenon is known as aerobic glycolysis or Warburg effect. This switching toward glycolysis implies that cancer tissues metabolize approximately tenfold more glucose to lactate in a given time and the amount of lactate released from cancer tissues is much greater than from normal ones. In view of these fundamental discoveries alterations of the cellular metabolism should be considered a crucial hallmark of cancer. Therefore, the investigation of the metabolic differences between normal and transformed cells is important in cancer research and it might find clinical applications. The aim of the project was to investigate the cellular metabolic alterations at single cell level, by monitoring glucose and lactate, in order to provide a better insight in cancer research. For this purpose, electrochemical techniques have been applied. Enzyme-based electrode biosensors for lactate and glucose were –ad hoc- optimized within the project and used as probes for Scanning Electrochemical Microscopy (SECM). The UME biosensor manufacturing and optimization represented a consistent part of the work and a full description of the sensor preparation protocols and of the characterization methods employed is reported. This set-up (SECM used with microbiosensor probes) enabled the non-invasive study of cellular metabolism at single cell level. The knowledge of cancer cell metabolism is required to design more efficient treatment strategies.
Resumo:
The electrochemical conversion is a sustainable way for the production of added-value products, operating in mild conditions, using in-situ generated hydrogen/oxygen by water and avoiding the use of high H2/O2 pressures. The aim of this work is to investigate the electrocatalytic conversion of 5-hydroxymetilfurfural (HMF) and D-glucose, in alkaline media, using metallic open-cell foams based-catalysts. The electrochemical hydrogenation of HMF to 2,5-bis(hydroxymethyl)furan (BHMF) was performed using nanostructured Ag, deposited by galvanic displacement (GD) or electrodeposition (ED), on Cu foam, obtaining AgCu bimetallic nanoparticles (ED) or dendrites (GD) which enhanced electroactive surface area, charge and mass transfer, than bare foams. In diluted 0.02M HMF solutions, Ag/Cu samples selectively produce BHMF; the large surface area enhanced the productivity, compared to their 2D counterparts. Furthermore, at more concentrated solutions (0.05 – 0.10M) a gradually decrease of selectivity is observed. The performances of the electrodes is stable during the catalytic tests but a Cu-enrichment of particles occurred. The performances of Ni foam-based catalysts, obtained by calcination of Ni foam or by electrodeposition of Ni-hydroxide/Ni and Ni particle/Ni, were firstly investigated for the selective electrochemical oxidation of D-glucose toward gluconic acid (GO) and glucaric acid (GA). Then, the calcined catalyst was chosen to study the influence of the reaction conditions on the reaction mechanism. The GO and GA selectivities increase with the charge passed, while the formation of by-products from C-C cleavage/retro-aldol process is maximum at low charge. The fructose obtained from glucose isomerization favours the formation of by-products. The best glucose/NaOH ratio is between 0.5 and 0.1: higher values suppress the OER, while lower values favour the formation of low molecular weight products. The increases of the potential enhance the GO selectivity, nevertheless higher GA selectivity is observed at 0.6 – 0.7V vs SCE, confirmed by catalytic test performed in gluconate (30-35% GA selectivity).
Resumo:
This doctoral thesis presents a project carried out in secondary schools located in the city of Ferrara with the primary objective of demonstrating the effectiveness of an intervention based on Well-Being Therapy (Fava, 2016) in reducing alcohol use and improving lifestyles. In the first part (chapters 1-3), an introduction on risky behaviors and unhealthy lifestyle in adolescence is presented, followed by an examination of the phenomenon of binge drinking and of the concept of psychological well-being. In the second part (chapters 4-6), the experimental study is presented. A three-arm cluster randomized controlled trial including three test periods was implemented. The study involved eleven classes that were randomly assigned to receive well-being intervention (WBI), lifestyle intervention (LI) or not receive intervention (NI). Results were analyzed by linear mixed model and mixed-effects logistic regression with the aim to test the efficacy of WBI in comparison with LI and NI. AUDIT-C total score increased more in NI in comparison with WBI (p=0.008) and LI (p=0.003) at 6-month. The odds to be classified as at-risk drinker was lower in WBI (OR 0.01; 95%CI 0.01–0.14) and LI (OR 0.01; 95%CI 0.01–0.03) than NI at 6-month. The odds to use e-cigarettes at 6-month (OR 0.01; 95%CI 0.01–0.35) and cannabis at post-test (OR 0.01; 95%CI 0.01–0.18) were less in WBI than NI. Sleep hours at night decreased more in NI than in WBI (p = 0.029) and LI (p = 0.006) at 6-month. Internet addiction scores decreased more in WBI (p = 0.003) and LI (p = 0.004) at post-test in comparison with NI. Conclusions about the obtained results, limitations of the study, and future implications are discussed. In the seventh chapter, the data of the project collected during the pandemic are presented and compared with those from recent literature.