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Innovative and eco-friendly approaches to mitigate Microbiologically Influenced Corrosion
No full textMicrobiologically influenced corrosion (MIC) is a type of corrosion caused or accelerated by microorganisms, such as bacteria, fungi, and algae. The metabolic activity of corrosive microorganisms influences the electrochemical processes that degrade materials, especially metals, leading to pitting or crevice formation that significantly increase their deterioration rate. MIC affects various industries, including oil and gas, petrochemical, water treatment, marine, as well as any system where metals are exposed to water, soil, or humid environments. The economic burden of MIC is immense, contributing up to 20% of global corrosion-related costs, approximately US$ 2.5 trillion annually in the oil and gas sector alone, excluding its safety and environmental impacts. Counteracting MIC requires a combination of preventative and corrective measures. Sulfate-reducing bacteria (SRB) are the major contributors to MIC due to their production of hydrogen sulfide, which accelerates corrosion. Effective strategies for eliminating or controlling SRB involve both physical and chemical methods. These last face challenges such as toxicity and high disposal costs, calling for sustainable alternatives.
This PhD thesis explore two innovative and eco-friendly approaches with the aim of contributing to the development of novel strategies to manage and control MIC. The first approach investigates the potential use of cinnamaldehyde, a compound with well-documented antimicrobial and anticorrosive properties. We found that low concentration of cinnamaldehyde (i.e., 12.5 μg/ml) inhibited the growth and killed Desulfovibrio vulgaris planktonic cells and almost eradicate pre-formed biofilms at 50 μg/ml, by reducing biomass (> 90 %), surface area (> 85 %) and thickness (> 60 %), with comparable efficacy to the conventional biocide, glutaraldehyde. Interestingly, we were able to show that cinnamaldehyde effectively disrupts pre-formed D. vulgaris biofilms also on representative metal coupons. These results pave the way for the future development of green sustainable strategies involving the use of cinnamaldehyde to mitigate MIC. The second approach regards the application of endolysins to control the SRB growth. Endolysins are hydrolytic enzymes encoded by bacteriophages during their lytic cycle, targeting the bacterial peptidoglycan layer, thus promoting osmotic lysis. Their fast lytic activity can also be accomplished when exogenously applied as recombinant proteins. These enzymes have garnered significant attention for their efficacy against clinically-relevant pathogens and are currently employed in clinical settings. However, their application in environmental contexts, particularly those impacted by MIC remains largely unexplored. We have selected and tested D. vulgaris-specific endolysins, demonstrating their effectiveness against D. vulgaris planktonic cells. Although preliminary, these promising results highlight the potential of endolysins in the sustainable management of MIC, bypassing the use of conventional toxic biocides. Finally, a case study highlighting the importance of microbiological investigations as a proactive MIC prevention strategy, to advocate for the incorporation of microbial community characterization into MIC management practices. Such proactive approaches will offer a potential to improve early detection and mitigation strategies, protecting marine infrastructures from corrosion-related failures
THE RIGHT TO RESIST AND THE HIERARCHISATION OF CITIZENSHIP. CHALLENGING HOW POLICY PRODUCES VULNERABILITY
Get PDFThe study explores how realities of migrants' and allies' collective organising, dissenting from the Italian institutional discourse on “migration”, produce knowledges that can offer alternative spaces to rethink the evolution of the law. It analyses how (im)mobility is problematised in Italian and European policy, arguing that the migrant person’s condition of socio-juridical vulnerability is produced by the law itself. Interrogating the contingency of the existing system and its inegalitarian and hierarchical structures, the research approaches the current order of things through the question: 'what if it was otherwise?'. Informed by the counternarratives of the migrant political subject, it attempts to create a space for criticism and reinterpretation of policy where the dogmatic paradigms of the sovereign state, the border, security, citizenship and the rights attached to it are approached as assumptions that can be contested and denaturalised. Arguing that migrants’ and allies’ realities promote a vision of substantial equality while seeking legal reform, the study reflects on the right of resistance in the context of the social conflict, with a view to explore the potential that this has for normative change and for the evolution of constitutional principles guarding the human person in their corporeality, as inhabitant of the earth.The study explores how realities of migrants' and allies' collective organising, dissenting from the Italian institutional discourse on “migration”, produce knowledges that can offer alternative spaces to rethink the evolution of the law. It analyses how (im)mobility is problematised in Italian and European policy, arguing that the migrant person’s condition of socio-juridical vulnerability is produced by the law itself. Interrogating the contingency of the existing system and its inegalitarian and hierarchical structures, the research approaches the current order of things through the question: 'what if it was otherwise?'. Informed by the counternarratives of the migrant political subject, it attempts to create a space for criticism and reinterpretation of policy where the dogmatic paradigms of the sovereign state, the border, security, citizenship and the rights attached to it are approached as assumptions that can be contested and denaturalised. Arguing that migrants’ and allies’ realities promote a vision of substantial equality while seeking legal reform, the study reflects on the right of resistance in the context of the social conflict, with a view to explore the potential that this has for normative change and for the evolution of constitutional principles guarding the human person in their corporeality, as inhabitant of the earth
Un’antologia di miti in marmo tra Grecia e Roma
No full textThe paper aims to point out the relations between visual and literary culture in the Spada and Colonna marble reliefs, produced in the first half of the 2nd century AD
Magnetic scaffolds for the mechanotransduction stimulation in tendon tissue regeneration
Get PDFNowadays, tendon injuries represent a global health issue that annually affects millions of individuals. An innovative approach for their treatment is represented by the development of tissue engineered scaffolds able to support the host cells adhesion, differentiation, and proliferation. However, the scaffold alone could be insufficient to guarantee an improvement of healing control. Magnetite nanoparticles (Fe3O4 NPs) are gaining interest due to their unique properties. In particular, when combined with bio-mimetic scaffolds, they should lead to the cells mechano-stimulation, improving the tenogenic differentiation and allowing a deeper tissue reparation. The aim of this work is the study and the development of scaffolds based on polyhydroxybutyrate and gelatin and doped with Fe3O4 NPs. The scaffolds are characterized by an aligned fibrous shape able to mimic the tendon fascicles. Moreover, they possess a superparamagnetic behavior and a slow degradation rate that should guarantee structural support during the tissue regeneration. The magnetic scaffolds promote cell proliferation and alignment onto the matrix, in particular when combined with the application of an external magnetic field. Also, the cells are able to differentiate and produce collagen I extracellular matrix. Finally, the magnetic scaffold in vivo promotes complete tissue healing after 1 week of treatment when combined with the external magnetic stimulation
Synthesis of new fluorescent compounds of biological interest: application in the detection of toxic metals in cells of marine and terrestrial biomarkers
No full textWith the rapid development of industrialization, economic conditions and social employment, the problem of environmental pollution is growing and concerns about heavy metals (HMs) are rising. HMs selective detection has developed into an essential branch of research in chemistry, biology, environmental, agricultural science and food safety. In this thesis project, four fluorescent probes (FLY, AJ2NBD, AJ2DAN and HNBO-DEN) were evaluated as optical chemosensors for the detection of selected metal ions in both solution and biological environment. While FLY and AJ2NBD were previously synthesized and characterized, AJ2DAN and HNBO-DEN represent two new molecules. All compounds feature a fluorophore moiety (NBD, dansyl and HNBO) bound to a macrocycle or open chain polyamine scaffold. The ability to act as fluorescent sensors was assessed by spectroscopic studies in solution. AJ2DAN revealed as a pH probe in aqueous solution, being OFF at strong acidic pH and ON at pH > 4, based on a PCT fluorescence mechanism, and showing large Stokes shifts. HNBO-DEN revealed an ESIPT-based fluorescence mechanism for the free ligand in both aprotic (ACN and DMSO) and protic polar solvents (water and EtOH-water mixture). The
study of the binding properties towards metal ions pointed instead at a different fluorescence mechanism, with the emission growing along with the deprotonation of HNBO group. The selectivity towards metal ions depends on the solvent, shifting from Mg2+, in DMSO and ACN, to Zn2+ and Cd2+, in THF, dioxane, water, methanol and ethanol. HNBO-DEN was also conjugated to NFR 700 NPs (DEN-NPs) and the binding yields were evaluated. Several functional studies of the four fluorescent dyes were performed for biologic applications. HT-29 and Caco-2 cell lines were labelled by AJ2DAN, highlighting absence of dye induced toxicity, indeed Chloroquine application, a known inhibitor of autophagic flux reducing autophagosome-lysosome fusion, causes the rise of autophagic intermediates and leads to the increase of AJ2DAN mean fluorescence intensity (MFI). These data suggest AJ2DAN as a potential probe to detect autophagic intermediates and intracellular vacuoles
with not too low pH values. HNBO-DEN shown Cadmium-dependent fluorescence in both HT-29 cells and mussel haemocytes. In the former, the dye yielded better results after a 24-hour Cd(II) exposure, while in haemocytes it detected Cd(II) more effectively after 30 minutes of treatment. This difference seems to reside in the specific characteristics of the cell models to respond to Cd(II) pollution. The DEN-NPs showed similar results. FLY and AJ2NBD were employed in environmental studies, using hepatopancreas of Armadillidium vulgare (a bioindicator and bioaccumulator organism). These dyes can support biologic analyses on polluted samples and may provide the basis for their potential use in environmental diagnostics using flow cytometry.With the rapid development of industrialization, economic conditions and social employment, the problem of environmental pollution is growing and concerns about heavy metals (HMs) are rising. HMs selective detection has developed into an essential branch of research in chemistry, biology, environmental, agricultural science and food safety. In this thesis project, four fluorescent probes (FLY, AJ2NBD, AJ2DAN and HNBO-DEN) were evaluated as optical chemosensors for the detection of selected metal ions in both solution and biological environment. While FLY and AJ2NBD were previously synthesized and characterized, AJ2DAN and HNBO-DEN represent two new molecules. All compounds feature a fluorophore moiety (NBD, dansyl and HNBO) bound to a macrocycle or open chain polyamine scaffold. The ability to act as fluorescent sensors was assessed by spectroscopic studies in solution. AJ2DAN revealed as a pH probe in aqueous solution, being OFF at strong acidic pH and ON at pH > 4, based on a PCT fluorescence mechanism, and showing large Stokes shifts. HNBO-DEN revealed an ESIPT-based fluorescence mechanism for the free ligand in both aprotic (ACN and DMSO) and protic polar solvents (water and EtOH-water mixture). The
study of the binding properties towards metal ions pointed instead at a different fluorescence mechanism, with the emission growing along with the deprotonation of HNBO group. The selectivity towards metal ions depends on the solvent, shifting from Mg2+, in DMSO and ACN, to Zn2+ and Cd2+, in THF, dioxane, water, methanol and ethanol. HNBO-DEN was also conjugated to NFR 700 NPs (DEN-NPs) and the binding yields were evaluated. Several functional studies of the four fluorescent dyes were performed for biologic applications. HT-29 and Caco-2 cell lines were labelled by AJ2DAN, highlighting absence of dye induced toxicity, indeed Chloroquine application, a known inhibitor of autophagic flux reducing autophagosome-lysosome fusion, causes the rise of autophagic intermediates and leads to the increase of AJ2DAN mean fluorescence intensity (MFI). These data suggest AJ2DAN as a potential probe to detect autophagic intermediates and intracellular vacuoles
with not too low pH values. HNBO-DEN shown Cadmium-dependent fluorescence in both HT-29 cells and mussel haemocytes. In the former, the dye yielded better results after a 24-hour Cd(II) exposure, while in haemocytes it detected Cd(II) more effectively after 30 minutes of treatment. This difference seems to reside in the specific characteristics of the cell models to respond to Cd(II) pollution. The DEN-NPs showed similar results. FLY and AJ2NBD were employed in environmental studies, using hepatopancreas of Armadillidium vulgare (a bioindicator and bioaccumulator organism). These dyes can support biologic analyses on polluted samples and may provide the basis for their potential use in environmental diagnostics using flow cytometry
Cryptocurrencies from Mainstream to Fringe Platforms. Media Manipulation and Deceptive Schemes on Facebook and Telegram
No full textThis article examines how cryptocurrency-related manipulative schemes leverage mainstream platforms like Facebook to channel users toward fringe environments such as Telegram, drawing on insights from a case study of coordinated link-sharing behavior. While this coordinated network originates in Nigeria and is first detected on Facebook, it quickly transcends international boundaries due to the transnational nature of distribution algorithms. These schemes exploit Facebook’s algorithmic architecture to amplify seemingly legitimate announcements, creating a deceptive sense of credibility before redirecting users to Telegram. Telegram, with its minimal oversight and decentralized ethos, then provides a fertile ground for disintermediated operations that exploit regulatory gaps. There, manipulative schemes – such as referral systems, giveaways, and gamified tasks – thrive in an unregulated and ephemeral ecosystem designed to sustain engagement and evade detection. This work highlights the cross-platform dynamics between mainstream and fringe platforms, showing how Facebook’s algorithmic visibility and Telegram’s permissive ecosystem complement one another in enabling manipulation. While the Digital Services Act (DSA) imposes obligations on Very Large Online Platforms (VLOPs), Telegram frequently escapes scrutiny due to its structural and operational characteristics. By analyzing link decay and bot activity, this study provides empirical insights into the adaptability of manipulative tactics across platforms. This research emphasizes the need for regulatory frameworks to address the interplay between mainstream and fringe platforms, adapting to the decentralized and transient ecosystems that shape digital manipulation
Ecotoxicological assessment of basil essential oil on soil nematode communities
Get PDFIntensive agriculture has over-exploited natural resources and altered the functioning of soil systems, mainly
because of the abuse of synthetic products to increase yields. To improve sustainability, the European Commission has adopted the New Green Deal program, which aims to reduce the use of synthetic products by 50%
and restore biodiversity by limiting human impact. Essential oils (EOs) can be sustainable alternatives to synthetic pesticides for crops and agricultural products protection against pests and diseases and, therefore, are
attracting increasing interest from the scientific community. However, while most studies have focused on in vitro
effects on target organisms (i.e., soil borne-phytopathogens, insects, phytoparasitic nematodes), the impact of
EOs on natural soil communities remains unexplored. This study employed a field experiment using the BeforeAfter-Control-Impact (BACI) approach to investigate the potential effects of basil EO on nematode communities.
Chickpea seeds were coated with a high concentration (25% v/v) of Ocimum basilicum EO in different formulations, with the basil EO and chitosan combination standing out for its potential applicability as a seed-coating
treatment for future crop use. The results demonstrated that the basil EO and chitosan seed coating had no
significant negative impact on nematode taxonomic diversity or functional indices. Furthermore, the taxonomic
community structure—recognized as the most sensitive detection metric—revealed that the observed effects
were primarily influenced by temporal changes, likely reflecting the natural progression of the crop system rather
than the EO treatment itself. These findings are particularly promising, as they suggest that EO-based coatings
can be compatible with maintaining soil health