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Characterization of H2 and hydrocarbons trapped in exhumed metamorphic rocks: origin and fluxes of energy sources in subduction zones
No full textMethane (CH4) and molecular hydrogen (H2) significantly influence Earth’s habitability, providing essential life ingredients in the deep subsurface, potentially Earth's largest biosphere. However, hydrocarbons and H2 origin, migration, distribution, and impact on deep life at convergent margins remain largely unconstrained. This PhD project investigates metamorphic hydrocarbons and H2 origin and migration through spectroscopic and isotopic analysis of fluid inclusions (FIs) in exhumed metamorphic terranes across the globe.
This research project addressed the analytical challenges associated with FIs isotope analysis by developing robust protocols for FIs mechanical extraction and δ13C-CH4 and δ13C-CO2 measurement through Cavity Ring-Down Spectroscopy. The protocols allowed replication of previously measured δ13C-CH4 values within 1 ‰ and enabled analysis of samples with CH4 and CO2 concentrations above 10 and 1000 ppm, respectively.
Fluid inclusion analysis from the Belvidere Mountain Complex, Northern Vermont, revealed insights into deep energy fluxes within the Taconian subduction zone. Changes in CH4 concentration and δ13C-CH4 across different lithological reservoirs depict a CH4-H2 "catch and release" mechanism driven by multiple fluid-rock interaction events. Methane isotopic evolution, from epidote-amphibolite to greenschist facies metamorphic conditions, reflects increasing input of metasediment-derived CH4 and/or transformation to graphite/carbonate.
The study of FIs in the Monte Maggiore ophiolite, Northern Corsica, demonstrated that subducted oceanic lithosphere can retain a diverse record of energy sources. Variations of CH4-C2H6 isotopes within populations of olivine-hosted FIs suggest changes in the settings of hydrocarbons and H2 genesis, from a mid-ocean ridge setting to high-pressure serpentinisation during the Alpine subduction. The complex isotopic patterns underscore our limited understanding of abiotic hydrocarbon formation through fluid-rock interactions.
This research provides new insights into the role of fluid-rock interactions in deep energy sources production and migration at subduction zones, emphasizing the need for further FI isotope studies to better understand the deep CH4-H2 cycle and its influence on Earth's habitability
Prognosis and safety evaluation of fatigue and corrosion-induced damages in reinforced concrete beams
No full textThe prognosis of a structural member's remaining life is subject to the durability of its materials. Chloride corrosion compromises concrete designed life, especially in the presence of cracks, which accelerate the initiation and propagation of corrosion. This thesis highlights the importance of considering load-induced cracks in the assessment and prediction of the service life. Different levels of damage were produced on four beams (2200x150x200 mm3) by static and fatigue loading, then, they were assessed using non-destructive electrochemical techniques in terms of reinforcement electrical potential and concrete electrical resistivity. The latter was simulated in a finite element model to compare the measured data with the numerical evaluations. Results revealed that the level of fatigue damage in concrete was directly related to the increase in corrosion risk assessed by resistivity and potential measurements. However, few studies discussed the change in resistivity with the mechanical response under compression. So, in order to study the relationship between mechanical load damage and concrete resistivity, an experiment was conducted on four concrete cylinders (150 x 75 mm2). Results showed a multi-phase behaviour with exponential correlation as follows: decreasing during elastic stage, quasi-constant in plastic, and increasing in post-failure stage. Additionally, the current codes limit the crack width to 0.2-0.4 mm depending on the exposure classes, these ranges do not satisfy the durability requirements as a narrower crack reduces the service life significantly. Therefore, a case study chosen from the literature was used to incorporate Torres’s chloride diffusion crack model as an alternative to Kwon’s model in the analytical solution for service life prediction of corroding structural element (i.e. the current model adopted by the fib MC). The suggested modification resulted in similar values yet with a higher accuracy in some cases
Unravelling new mechanisms in bone cancer progression
No full textOsteosarcoma (OS) and Ewing Sarcoma (EWS) are the most frequent primary bone tumors affecting pediatric patients. Lamin A, a nuclear protein constituting the nuclear lamina, plays a key role in maintaining nuclear shape, organizing the nuclear envelope (NE), and ensuring mechanical stability. The interplay between lamins and LINC (linker of nucleoskeleton and cytoskeleton) complex proteins facilitates the transmission of mechanical signals from the extracellular matrix to the nucleus. It’s disruption can significantly affect migration and invasiveness involved in tumor progression. We explored the role of NE proteins in OS, investigating how alterations in lamin A levels influence the expression and localization of LINC complex. We found reduced lamin A levels in OS, compared to osteoblasts, while its overexpression influences LINC complex protein expression and localization, leading to decreased invasiveness. Also, differentiated OS cells, showed an upregulation of lamin A, and a significant modulation of LINC complex, similarly to the effects obtained with the overexpression of lamin A. Thus, restoring physiological NE could prove crucial for OS, where non-toxic, differentiation-based strategies are urgently needed. In addition, we turned our attention to the aggressive nature of EWS, which is profoundly influenced by epigenetic mechanisms. Thus, we investigated the role of UHRF1, a key player in epigenetic reprograming and in tumor progression across various cancers. UHRF1 is known to regulate gene expression through DNA methylation, and acts as a cell cycle controller, impacting cell growth, apoptosis, DNA repair, and histone modifications. We assessed UHRF1 expression in EWS patients and found that it is upregulated in metastatic versus primary EWS tumors, affecting patient survival. Our transcriptomic analysis of EWS cells knocked-down for UHRF1 revealed a significant modulation of various effectors involved in EWS progression, warranting further investigation
Long term prediction and prevention of known and emerging biological hazards for animal and human health testing microbiomes circulating in sewage
No full textClimate change and global warming are causing catastrophic effects to humans, animals, and ecosystems, including the emergence of new biological hazards due to altered habitats, zoonotic spillover, and release of ancient pathogens. Current infection tracking methods face challenges such as overlooking asymptomatic cases and delays in data. Sewage surveillance, successfully employed during the COVID-19 pandemic, has proven effective as an early warning system for detecting infectious agents, reflecting the microbiome of a community. My PhD project investigates wastewater analysis for monitoring and predicting emerging biological hazards, particularly in the context of climate change, as highlighted by the EFSA report. Two experimental studies were conducted: one in Bologna, Italy, and another in Nantes, France. A longitudinal study in Bologna used shotgun metagenomics to map the sewage microbiome, identify pathogens, and correlate findings with climatic data. Within the VEO project, seasonal and environmental impacts on microbial communities were explored by recovering genomes directly from metagenomic data. In France, sewage and shellfish samples were analysed in collaboration with IFREMER to characterize the virome. Various next-generation sequencing protocols were tested to optimize detection of foodborne viruses in complex environmental matrices. A literature review further explored the integration of sewage and clinical data to identify foodborne pathogens and strengthen outbreak prevention. The sequencing analysis of sewage samples from the Bologna wastewater treatment plant revealed a dominant presence of Escherichia coli and fluctuating levels of Salmonella enterica and Vibrio cholerae. In France, a specific RNA sequencing workflow was most effective for strain-level viral differentiation. Case studies suggest sewage surveillance can monitor foodborne pathogens and detect trends exceeding baseline thresholds, offering a valuable preventive tool. The research highlights the potential of sewage-based surveillance for monitoring enteric viruses and microbial diversity in environmental and food samples, despite challenges with metagenomic variability and microorganism classification
Sustainable valorization of lignocellulosic biomass for the production of chemicals and fuels
No full textThe thesis focuses on developing an innovative biorefinery scheme that integrates various catalytic processes—specifically Reductive Catalytic Fractionation (RCF), Aqueous Phase Reforming (APR), and HydroDeOxygenation (HDO)—to produce sustainable energy products like hydrogen, aromatic compounds, and cellulose pulp. The primary aim is to optimize the RCF step to fully valorize lignocellulosic biomass, which includes cellulose, hemicellulose, and lignin. Significant challenges include preventing lignin repolymerization without proper reductive stabilization, achieving simultaneous extraction of hemicellulose and lignin for pure cellulose pulp production, and recovering catalysts from the solid pulp. The research introduces a novel class of magnetic γ-Fe2O3-supported catalysts that effectively address these challenges, enhancing both the yield of lignin oil and the purity of cellulose pulp while facilitating catalyst recovery and reuse. Additionally, the study explores the HydroDeOxygenation of the lignin fraction and APR of hemicellulose-derived fractions using model molecules to determine optimal processing conditions for real biomass streams. The RCF process was tested on industrial waste biomasses, demonstrating scalability through collaboration with ENI Renewable, New Energies and Material Science Research Center. Overall, this work presents a versatile biorefinery scheme aimed at producing key bulk end products essential for the energy transition, emphasizing the importance of optimizing catalytic processes in sustainable biomass conversion
Smart luminescent materials: probes for environmental and bio-analytical applications
No full textPolymers have proved to be promising materials for widespread use in many fields. Their useful properties, such as affinity with analytes, biocompatibility, biodegradability, resistance and flexibility, together with the presence of functional groups, allow for their use in many applications, but also open the possibility to modify their chemical structure and introduce additional moieties and novel properties, to design new “smart” materials. In this PhD thesis, we aimed to prepare novel polymeric materials – based on biopolymers - for sensing in environmental applications and as supports for biomedical and even artistic-cultural applications. Starting from our research group’s background in the preparation of fluorogenic polymer probes, we carried out chemical synthesis to improve the solubility, stability and selectivity of polymer probes, but also to introduce photoactive moieties into the structure. Using conventional and advanced spectroscopic and microscopic techniques, we have characterized such materials in terms of the efficacy of the synthetic procedures, photophysical properties, morphology and actual performance in respective applications. Successful derivatization and optimal photophysical properties related to the physico-chemical structure were obtained, yielding materials able to match the required features for the envisaged applications. In particular, promising interactions with Micro- and Nano Plastics (MNPs) showed the possibility of identifying them in complex water samples, while the preparation of doped non-woven scaffolds showed promising results for localized in situ therapy and restoration applications. Such favourable results represent an encouraging step towards the improvement of already proposed approaches, in terms of selectivity and cost-effectiveness, but also as faster, simpler and more controlled procedures. In conclusion, this research contributes to the field of the development and application of versatile polymeric materials to exploit and improve their properties for future use in important fields of great socio-economical impact such as public health
Unveiling the Neural Code: computing intentions in V6A
No full textThe title of this thesis, Unveiling the Neural Code: Computing Intentions in V6A, reflects the overarching objective of elucidating the brain’s processing of motor intentions during spatial target perception, with a specific focus on the V6A parietal cortical area. The primary focus of this thesis is revealing the computations occurring within V6A in motor intentions related to spatial target perception. The findings herein highlight V6A’s crucial role in translating sensory inputs into actionable motor plans, bridging perception and action within the brain’s sensorimotor circuitry. The second major contribution of this work proposes advanced methods for analysis of the neural activity inspired by biological processes. The brain-inspired decoding approach is grounded in the concept of predictive coding, a fundamental principle in brain function. In particular, the framework of active inference, suggests that the brain continuously predicts sensory inputs and motor outcomes, refining its actions through feedback. This bio-inspired model not only aligns with the current understanding of predictive coding but also offers a novel perspective on how motor intentions are formed and executed. The transferability of this model across different neural datasets is demonstrated. In collaboration with the Spanish research center Tecnalia, neural data recorded from a human patient with a motor cortex (M1) lesion following a stroke were analyzed. This dataset allowed for testing the robustness of the model and exploring its applicability beyond V6A, providing insights into neural recovery and compensation mechanisms in damaged cortical areas. This research thesis elucidates the neural code underlying motor intentions and offer models that can potentially inform the design of future neural interfaces and rehabilitation strategies
“Role of 18-Fet in high grade gliomas re-irradiation: from detection of disease recurrence to a predictive value"
No full textMost high-grade gliomas (HGGs) recur after initial multimodal therapy and re-irradiation (Re-RT) has been shown to be a valuable re-treatment option in selected patients.
MRI is the gold standard for diagnosis and treatment planning of HGGs, but has some limits to differentiate between some lesions that can occur after treatments and the recurrence.
18F-fluoroethyl-tyrosine (FET) has been proven to be able to non-invasively differentiate treatment-related changes from real tumor progression and could also have a predictive potential in response of treatment.
The presence of hypoxic cells in high-grade glioma (HGG) is one of the main reasons of local failure after radiotherapy (RT). The use of hyperbaric oxygen therapy (HBO) could help to overcome the problem of hypoxia in poorly oxygenated regions of the tumor. HBO-RT is a pilot trial to evaluate the efficacy of hypofractionated image-guided helical TomoTherapy (HT) after HBO in the treatment of recurrent HGGs.
In a group of patients enrolled in HBO-RT trial FET was acquired before and after treatment and we performed a retrospective analysis to evaluate the ability of FET to discriminate between HGGs recurrence and treatment-related changes (TRC) and the predictive potential of FET acquired before hyperbaric re-irradiation of recurrent high-grade gliomas along with other imaging and clinical parameters
Common traits, interpretative categories and international trends in picturebook studies
No full textQuesto studio si propone di identificare la presenza di eventuali tratti comuni all’interno degli studi specifici sulle illustrazioni all’interno degli albi illustrati, utili a poterne definire eventuali indici di qualità. Attraverso un metodo ermeneutico, comparativo (Bernardi 2016) e narrativo (Petticrew, Roberts 2006), sono state prese in esame fonti nazionali e internazionali degli ultimi trentacinque anni, identificati come il periodo di maggior cambiamento riguardo la considerazione del picturebook come opera e come genere tout court. Tale percorso filologico e aperto alle suggestioni ha permesso l’identificazione di elementi ricorrenti inquadrabili all’interno di quattro macrocategorie interpretative condivise: complessità, dinamicità, atipicità e gratuità. Ma non solo: poiché, infatti, un albo illustrato che trova parte della sua ragion d’essere proprio nel rapporto con il mediatore (l’adulto) e il lettore (il bambino), si è potuto evincere come, a queste quattro caratteristiche proprie delle illustrazioni giudicate come virtuose all’interno degli albi illustrati, corrispondano altrettante posture pedagogiche utili a interrogare chi si occupa di educazione, al fine di adempiere alla responsabilità di educazione estetica, letteraria ed emotiva dell’infanzia con consapevolezzaThis study aims to identify the presence of any common traits within the specific studies on illustrations in picturebooks, useful to define possible quality indices. Through a hermeneutic, comparative (Bernardi 2016) and narrative method (Petticrew, Roberts 2006), national and international sources of the last thirty-five years have been examined, identified as the period of greatest change in regard to picturebook as a work and as a genre tout court. This philological path, open to suggestions, has allowed the identification of recurring elements that can be framed within four shared interpretative macro-categories: complexity, dynamics, atypical and gratuitous. But not only: since, in fact, a picturebook that finds part of its raison d'être precisely in the relationship with the mediator (the adult) and the reader (the child), it has been possible to to these four characteristics of the illustrations judged as virtuous within picturebooks, correspond as many pedagogical postures useful to question those who deal with education, in order to fulfill the responsibility of aesthetic education, Literary and emotional childhood with awareness
Quantitative assessment of safe and sustainable strategies in the pursuit of decarbonisation
No full textDecarbonisation is a pressing challenge driven by climate change, necessitating strategies that balance environmental, societal, economic, and technological considerations. This Ph.D. research developed quantitative assessment tools to evaluate the safety-related societal impacts of decarbonisation strategies and incorporate them into a comprehensive sustainability framework. Inherent safety key performance indicators (IS-KPIs) were introduced to enable societal impact quantification and systematically integrated with specific technological, economic and environmental sustainability metrics. The robustness and applicability of the developed methodology were tested for two different case studies representative of transport and industrial applications, i.e., maritime transport and hard-to-abate sectors. In maritime transport, alternative fuels, including hydrogen, ammonia, and e-fuels, were evaluated, with e-methanol emerging as a viable option due to its moderate hazards and compatibility with existing infrastructure. While hydrogen and ammonia could reduce environmental impacts by at least 88% compared to e-fuels, their inherent hazards were up to 93 times higher. Hence, the development of robust and safe infrastructure and protocols is paramount for their widespread implementation. Onboard carbon capture and storage (OCCS) demonstrated potential for reducing emissions by up to 68%, promoting its adoption as a transitional solution until cleaner fuels become viable. For industrial decarbonisation, carbon capture and storage (CCS) was examined for mitigating hard-to-abate emissions. Sustainability decreased significantly at smaller emission scales, with costs rising by up to 300% when the targeted scale was 14 times lower. To mitigate costs, a centralised CCS strategy for smaller, spatially dispersed emitters is recommended, reducing costs by at least 25% compared to on-site CCS. The concept was extended to hydrogen-based strategies using liquid organic hydrogen carriers, which outperformed CCS for combustion-driven emissions, though CCS remained the most effective solution for process-related emissions. This research provides practical insights for developing and implementing safer and more sustainable decarbonisation technologies that align with global climate targets