Tesis: "Chimera method"

1

Galbraith, Marshall C. "A Discontinuous Galerkin Chimera Overset Solver". University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1384427339.

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2

Stern, Louis G. "An explicitly conservative method for time-accurate solution of hyperbolic partial differential equations on embedded Chimera grids /". Thesis, Connect to this title online; UW restricted, 1996. http://hdl.handle.net/1773/6758.

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3

Demir, H. Ozgur. "Computational Fluid Dynamics Analysis Of Store Separation". Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605294/index.pdf.

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In this thesis, store separation from two different configurations are solved using computational methods. Two different commercially available CFD codes
CFD-FASTRAN, an implicit Euler solver, and an unsteady panel method solver USAERO, coupled with integral boundary layer solution procedure are used for the present computations. The computational trajectory results are validated against the available experimental data of a generic wing-pylon-store configuration at Mach 0.95. Major trends of the separation are captured. Same configuration is used for the comparison of unsteady panel method with Euler solution at Mach 0.3 and 0.6. Major trends are similar to each other while some differences in lateral and longitudinal displacements are observed. Trajectories of a fueltank separated from an F-16 fighter aircraft wing and full aircraft configurations are found at Mach 0.3 using only the unsteady panel code. The results indicate that the effect of fuselage is to decrease the drag and to increase the side forces acting on the separating fueltank from the aircraft. It is also observed that the yawing and rolling directions of the separating fueltank are reversed when it is separated from the full aircraft configuration when compared to the separation from the wing alone configuration.

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4

Dorange, Alexis. "Développement d'une méthodologie pour la simulation haute fidélité de l'aérodynamique des micro-drones". Electronic Thesis or Diss., Institut polytechnique de Paris, 2024. http://www.theses.fr/2024IPPAX103.

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L'objectif cette thèse est le développement d'une méthodologie permettant la simulation haute fidélité de tous types de géométries de micro-drones.Bien que ces véhicules soient très présents dans l'espace aérien, la physique des écoulements qu'ils induisent est encore mal connue, en outre ils sont associés à des problématiques de nuisance acoustique.L'écoulement autour de ces derniers présente des phénomènes complexes de mécanique des fluides tels que la transition laminaire-turbulent, la séparation ou encore un bulbe de décollement laminaire.La Simulation des Grandes Échelles (Large Eddy Simulation - LES) est mise en œuvre dans cette étude car elle permet de prendre en compte avec précision les phénomènes complexes mis en jeu dans la couche limite des hélices de drone, au contraire des approches de plus basses fidélités.Une autre problématique liée aux drones est leur géométrie complexe, qui peut grandement compliquer l'étape de génération de maillage en vue de leur simulation. Dans cette optique, les méthodes Chimère et de frontières immergées sont utilisées pour simplifier cette étape. La première permet de mailler indépendamment et plus simplement chacune des pales à l'aide de maillages structurées curvilignes, tandis que la seconde permet de s'affranchir de la génération d'un maillage conforme autour du fuselage. Un couplage entre ces deux méthodes est finalement développé pour la simulation d'éléments géométriques très proches les uns des autres.Tout d'abord, les résultats d'une simulation LES sont présentés pour un rotor dont la géométrie des pales est entièrement définie analytiquement. Cette simulation permet de mettre en évidence la présence d'un bulbe de séparation laminaire ainsi que des mécanismes de rattachements et de décollements laminaires et turbulents. Elle met également en évidence les différentes sources de bruit générées par les hélices.Par la suite, une étude sur la montée en complexité géométrique permet de mesurer l'effet de l'ajout des différentes parties du drone sur les performances du rotor. En particulier, ces simulations mettent en avant l'impact du moyeu et des bras sur les efforts aérodynamiques, ainsi que les émissions acoustiques globales.Au terme de cette thèse, un drone complet est finalement simulé à l'aide de l'ensemble des éléments méthodologiques introduits dans le cadre de ces travaux. Les efforts globaux ainsi que l'acoustique complète du drone sont analysés. Cette application représente la première simulation connue d'un drone complet réalisée à l'aide d'une approche LES
The objective of this thesis is to develop a methodology for the high-fidelity simulation of all types of micro-unmanned aerial vehicle geometry.Despite their prevalence in the airspace, the flow physics they induce remain poorly understood and present acoustic nuisance issues.The flow around these vehicles presents a range of complex fluid mechanics phenomena, including the laminar-turbulent transition, separation, and the formation of a laminar separation bubble.The Large Eddy Simulation (LES) approach is employed in this study to accurately account for the complex phenomena occurring within the boundary layer of drone propellers, which cannot be adequately captured by lower fidelity methods.A further issue associated with UAVs is their complex geometry, which can significantly complicate the mesh generation process for their simulation.In consideration of the aforementioned considerations, the Chimera and immerged boundary methods are employed to simplify this stage. The former facilitates the meshing by using curvilinear structured meshes for each blade independently, while the latter eliminates the need to generate a conformal mesh around the fuselage. A coupling between these two methods is finally developed for the simulation of geometric elements that are in close proximity to one another.In the first instance, the results of an LES simulation are presented for a rotor whose blade geometry is entirely defined analytically. The simulation demonstrates the presence of a laminar separation bubble as well as laminar and turbulent attachment and detachment mechanisms. Furthermore, the simulation highlights the various sources of noise generated by the propellers.Subsequently, an investigation into of increasing geometric complexity on rotor performance was conducted by incorporating different components into the UAV. In particular, these simulations demonstrate the influence of the hub and arms on aerodynamic forces and overall acoustics emissions.At the conclusion of this thesis, a complete UAV is finally simulated using all the methodological elements introduced as part of this work. The overall forces and the complete acoustics of the UAV are analysed. This application represents the first known simulation of a complete UAV using an LES approach

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5

Taylor, Mary. "In vitro methods for the construction of chimeras in potato". Thesis, University of Bath, 1988. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383696.

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6

Montroni, Elisa <1986&gt. "New Methods in Organocatalysis". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6336/1/Montroni_Elisa_tesi.pdf.

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In the following chapters new methods in organocatalysis are described. The design of new catalysts is explored starting from the synthesis and the study of ion tagged prolines to their applications and recycle, then moving to the synthesis of new bicyclic diarylprolinol silyl ethers and their use in organocatalytic transformations. The study of new organocatalytic reaction is also investigated, in particular bifunctional thioureas are employed to catalyse the conjugate addition of nitro compounds to 3-yilidene oxindoles in sequential and domino reactions. Finally, preliminary results on photochemical organocatalytic atom transfer radical addition to alkenes are discussed in the last chapter.

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7

Montroni, Elisa <1986&gt. "New Methods in Organocatalysis". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6336/.

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In the following chapters new methods in organocatalysis are described. The design of new catalysts is explored starting from the synthesis and the study of ion tagged prolines to their applications and recycle, then moving to the synthesis of new bicyclic diarylprolinol silyl ethers and their use in organocatalytic transformations. The study of new organocatalytic reaction is also investigated, in particular bifunctional thioureas are employed to catalyse the conjugate addition of nitro compounds to 3-yilidene oxindoles in sequential and domino reactions. Finally, preliminary results on photochemical organocatalytic atom transfer radical addition to alkenes are discussed in the last chapter.

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8

Moro, Lorenzo <1985&gt. "Complex chemical dynamics through engineering-like methods". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6202/1/TesiDoc_Moro.pdf.

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Most of the problems in modern structural design can be described with a set of equation; solutions of these mathematical models can lead the engineer and designer to get info during the design stage. The same holds true for physical-chemistry; this branch of chemistry uses mathematics and physics in order to explain real chemical phenomena. In this work two extremely different chemical processes will be studied; the dynamic of an artificial molecular motor and the generation and propagation of the nervous signals between excitable cells and tissues like neurons and axons. These two processes, in spite of their chemical and physical differences, can be both described successfully by partial differential equations, that are, respectively the Fokker-Planck equation and the Hodgkin and Huxley model. With the aid of an advanced engineering software these two processes have been modeled and simulated in order to extract a lot of physical informations about them and to predict a lot of properties that can be, in future, extremely useful during the design stage of both molecular motors and devices which rely their actions on the nervous communications between active fibres.

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9

Moro, Lorenzo <1985&gt. "Complex chemical dynamics through engineering-like methods". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6202/.

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Most of the problems in modern structural design can be described with a set of equation; solutions of these mathematical models can lead the engineer and designer to get info during the design stage. The same holds true for physical-chemistry; this branch of chemistry uses mathematics and physics in order to explain real chemical phenomena. In this work two extremely different chemical processes will be studied; the dynamic of an artificial molecular motor and the generation and propagation of the nervous signals between excitable cells and tissues like neurons and axons. These two processes, in spite of their chemical and physical differences, can be both described successfully by partial differential equations, that are, respectively the Fokker-Planck equation and the Hodgkin and Huxley model. With the aid of an advanced engineering software these two processes have been modeled and simulated in order to extract a lot of physical informations about them and to predict a lot of properties that can be, in future, extremely useful during the design stage of both molecular motors and devices which rely their actions on the nervous communications between active fibres.

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10

ODDONE, IRENE. "Vacuum Induced Nucleation as a method for freeze drying optimization". Doctoral thesis, Politecnico di Torino, 2016. http://hdl.handle.net/11583/2640463.

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Freeze drying is used to improve long-term stability of labile drugs. It comprises three different stages: freezing, primary drying, and secondary drying. Due to low values of pressure and temperature required in these stages, freeze drying is a cost-intensive process. Various authors have recently shown that the manipulation of the temperature of nucleation can provide benefits in terms of process optimization, and various technologies have been proposed to this purpose, such as electrofreezing, ultrasound, depressurization method, and ice fog. However, due to various problems of these technologies, such as the requirement of additional equipment and difficulties in scale-up, in this study the vacuum induced nucleation method was taken into consideration for its ease of application. Unfortunately, this method, as proposed in literature, produces defects in the cake structure because of blow-up of the frozen product and flake formation on the product surface, which are detrimental for the elegance of the final product and rejected by the pharmaceutical industry. For these reasons, a refined control technique has been here investigated and validated, showing that an accurate control of vacuum conditions can give a drastic reduction in cycle time along with an elegant product. The vacuum induced nucleation method consists in reducing the pressure within the drying chamber for a short time during the freezing stage. This pressure reduction produces the partial evaporation of water, which causes a reduction in product temperature and promotes the nucleation of ice. In this work I have developed a new method, still based on pressure reduction, that solved some of the problems of the original technique. In particular, once the desired value of pressure (which is product dependent) was reached, the drying chamber was isolated from the condenser for about 1 min. Because of that isolation, the pressure inside the drying chamber increased because of vapor accumulation, thus avoiding any esthetic defects to the product. A detailed investigation about the impact of the settings of the new control method on product and process performances was performed. To this purpose, various solutions containing mannitol, sucrose, lactose, dextran, glycine, polyvinylpyrrolidone, trehalose, and cellobiose were used. The results obtained showed that the method led to a high quality of the final product. Furthermore, showed that the induction of nucleation at higher temperature promoted the formation of very large crystals (see Fig. 1) with a consequent drastic reduction in cycle duration (due to lower values of product resistance to vapor flow, Rp). In order to promote the industrial scale-up of the method, a monitoring system based on thin-film technology, that allows, besides the monitoring of the product temperature, the detection of the end of the nucleation event was developed. Once the method was developed, a detailed investigation on its impact on both product (i.e., structure and homogeneity) and process (i.e., primary and secondary drying time) was carried out. The impact of the method on within-batch (inter-vial) and within-vial (intra-vial) variability was investigated. Comparing the onset-offset of pressure ratio curves of various cycles, it was found that the use of controlled nucleation (instead of conventional shelf-ramped freezing) dramatically increased the inter-vial homogeneity (by about 50%). This result was also confirmed by comparing the residual moisture values at the end of drying, which showed lower variance for controlled nucleation with respect to uncontrolled. A study, focused on mannitol-based formulations, showed that both nucleation temperature and filling volume had an impact on pore size and its distribution along the lyophilized cake. This within-vial variability was quantified by analyzing the average pore dimension along the cake (by Image-J program). The homogeneity of the product was also studied in terms of polymorph formation. To this regard, X-ray diffraction and off-line Raman were used to identify the mannitol polymorphs present within the product, which was found to vary with the freezing protocol and the temperature of secondary drying. Off-line Raman spectroscopy was also used to evaluate the polymorph distribution along the cake, showing that the spectra collected at the top of each sample often contained slightly higher amounts of α and δ mannitol in comparison with the spectra recorded in the other regions of the same cake. Finally, the Raman tool was also used for the in-line monitoring of the product characteristics, increasing the knowledge related to polymorph formation during freeze drying. To this purpose, it was found that the hydrate form of mannitol (which can damage the product if released during product storage) was formed during the entire cycle (freezing and drying stages), but was transformed into anhydrous polymorph immediately after the vacuum within the chamber was released at the end of the cycle. The primary drying stage of the cycles was performed using in-line monitoring (DPE+ algorithm) and control (LyoDriver) to further optimize the freeze-drying cycle. The use of these tools showed that, to obtain the optimum freeze-drying cycle, it was necessary to work on both freezing and primary drying stages. The mass-transfer resistance values obtained from each cycle (by DPE+ algorithm estimation) were used to calculate the design space and simulate the process. The cycle simulation highlighted the reduction of the cycle duration using the control method proposed (in comparison with an uncontrolled stochastic cycles) and the influence of its operating conditions on freeze-drying cycle optimization. It was, finally, shown that the primary drying duration could be decreased up to about 55% in the case of controlled nucleation. A study focused on the moisture content of the product during secondary drying showed that the controlled nucleation led to higher values of residual moisture content in comparison with conventional freezing. This comparison was done for different secondary drying temperatures. The estimated kinetic constant of desorption was always higher in the case of uncontrolled cycles with respect to that for the controlled cycles, thus resulting in an increase of time needed for desorption when controlled nucleation was used. This was an expected result as control of nucleation leads to higher porosity and, thus, to a lower specific surface area available for the desorption of residual moisture. Although higher values of residual moisture content led to an additional time needed in the case of controlled nucleation to complete secondary drying stage, it was found that the total time to carry out the entire cycle was still smaller in the case of controlled nucleation in comparison with uncontrolled, thus confirming the advantage in using this control technique. Finally, the design space built for the secondary drying stage gave additional information about the impact of some operating conditions of the process on secondary drying time, thus giving a great contribution in the optimization of this step. The difference in water content between conventional and controlled freezing protocol was also investigated by in-line NIR spectroscopy analysis. This technology was able to discriminate between bound and surface water in freeze dried products. Differences in bound and surface water were detected only in the case of different temperature during secondary drying independently from the freezing protocol used.

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11

MENESCARDI, FRANCESCA. "HIGH PRESSURE MATERIALS DISCOVERY WITH ADVANCED COMPUTATIONAL METHODS". Doctoral thesis, Università degli Studi di Milano, 2021. http://hdl.handle.net/2434/822394.

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The focus of this thesis is the prediction of new materials that can be formed or synthesized under high pressure. It has been shown by several works in literature, that pressure can alter the chemistry of an element by activating its (semi)core electrons, unoccupied orbitals and even the non-atom-centered quantum orbitals located on the interstitial sites, leading to many new surprising phenomena. In this work I applied three different strategies to predict new compounds under pressure:  explore known polymorphs (aka prototypes)  global optimization via genetic algorithms  data mining and high-throughput calculations The first strategy can be easily applied to compounds with few components, fixed stoichiometry and at moderate pressure. The idea is that atoms with similar radius and valence tend to crystallize with the same structure. This is the case of ABO3 oxides which constitute the largest family of oxides: the crystal structure at ambient pressure is found to depend on the atomic radii of the elements. The most common is the perovskite structure where tilting of octahedra and offcentering of the B-cation is responsible for a large variety of physical properties. In addition to the perovskite structure few other structures are know (i.e. ilmenite, wollastonite, calcite, aragonite, enstatite, corundum). The most important is the post-perovksite which is formed from the perovskite structure when the rotation of the octahedra exceeds a critical angle. The second strategy is more computationally expensive than the first and must used when the pressure is very high and when the stoichiometry is not fixed because of pressure-induced chemical reactions. In this case pressure induces such large changes in the valence configuration that no iso-structural compound exists at ambient pressure. Crystal structure prediction is in principle a computationally intractable problem. In recent years, clever optimization methods such as genetic algorithms (i.e. USPEX) have provided an effective and successful solution to this problem. The third strategy builds upon the ideas of the first strategy by trying to establish structure-property relations. Here the aim is to find new materials with specific physical properties by exploring existing databases. Where information is missing, high-through calculations are used to fill in the blanks. This field of research is very active and was boosted by machine learning in the last few years. The main drawback of machine learning is that it is not always interpretable and accessible to experimental groups. In this thesis I report two case studies: the first is the search of exfoliable topological materials and the search low/ambient-pressure post-perovskites. Calculations were performed employing plane wave code Quantum Espresso (QE). In addition to these three topics, my PhD work focused also on improving the reality of first principles calculations such that they can be directly compared to experiments. The first issue I addressed is the dependence of the calculated equations of state (EOS) on the choice of the exchange-correlation (XC) functional. This is extremely important in magnetic perovskites like SrRuO3 since the volume affects the magnetic moments and vice versa. I found the PBEsol functional reproduces the EOS and lattice parameters of perovskites with few exceptions. In the case of post-perovskites the calculated lattice parameters show some systematic deviations from the experimental ones.

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12

Ceccarini, Luisa <1980&gt. "Computational investigations of ion conduction mechanisms using enhanced sampling methods". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3780/1/Ceccarini_Luisa_tesi.pdf.

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Proper ion channels’ functioning is a prerequisite for a normal cell and disorders involving ion channels, or channelopathies, underlie many human diseases. Long QT syndromes (LQTS) for example may arise from the malfunctioning of hERG channel, caused either by the binding of drugs or mutations in HERG gene. In the first part of this thesis I present a framework to investigate the mechanism of ion conduction through hERG channel. The free energy profile governing the elementary steps of ion translocation in the pore was computed by means of umbrella sampling simulations. Compared to previous studies, we detected a different dynamic behavior: according to our data hERG is more likely to mediate a conduction mechanism which has been referred to as “single-vacancy-like” by Roux and coworkers (2001), rather then a “knock-on” mechanism. The same protocol was applied to a model of hERG presenting the Gly628Ser mutation, found to be cause of congenital LQTS. The results provided interesting insights about the reason of the malfunctioning of the mutant channel. Since they have critical functions in viruses’ life cycle, viral ion channels, such as M2 proton channel, are considered attractive targets for antiviral therapy. A deep knowledge of the mechanisms that the virus employs to survive in the host cell is of primary importance in the identification of new antiviral strategies. In the second part of this thesis I shed light on the role that M2 plays in the control of electrical potential inside the virus, being the charge equilibration a condition required to allow proton influx. The ion conduction through M2 was simulated using metadynamics technique. Based on our results we suggest that a potential anion-mediated cation-proton exchange, as well as a direct anion-proton exchange could both contribute to explain the activity of the M2 channel.

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13

Ceccarini, Luisa <1980&gt. "Computational investigations of ion conduction mechanisms using enhanced sampling methods". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3780/.

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Proper ion channels’ functioning is a prerequisite for a normal cell and disorders involving ion channels, or channelopathies, underlie many human diseases. Long QT syndromes (LQTS) for example may arise from the malfunctioning of hERG channel, caused either by the binding of drugs or mutations in HERG gene. In the first part of this thesis I present a framework to investigate the mechanism of ion conduction through hERG channel. The free energy profile governing the elementary steps of ion translocation in the pore was computed by means of umbrella sampling simulations. Compared to previous studies, we detected a different dynamic behavior: according to our data hERG is more likely to mediate a conduction mechanism which has been referred to as “single-vacancy-like” by Roux and coworkers (2001), rather then a “knock-on” mechanism. The same protocol was applied to a model of hERG presenting the Gly628Ser mutation, found to be cause of congenital LQTS. The results provided interesting insights about the reason of the malfunctioning of the mutant channel. Since they have critical functions in viruses’ life cycle, viral ion channels, such as M2 proton channel, are considered attractive targets for antiviral therapy. A deep knowledge of the mechanisms that the virus employs to survive in the host cell is of primary importance in the identification of new antiviral strategies. In the second part of this thesis I shed light on the role that M2 plays in the control of electrical potential inside the virus, being the charge equilibration a condition required to allow proton influx. The ion conduction through M2 was simulated using metadynamics technique. Based on our results we suggest that a potential anion-mediated cation-proton exchange, as well as a direct anion-proton exchange could both contribute to explain the activity of the M2 channel.

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14

Di, Martino Giovanni Paolo <1985&gt. "Computational Methods in Biophysics and Medicinal Chemistry: Applications and Challenges". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6329/1/Dissertation_Di_Martino.pdf.

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In this thesis I described the theory and application of several computational methods in solving medicinal chemistry and biophysical tasks. I pointed out to the valuable information which could be achieved by means of computer simulations and to the possibility to predict the outcome of traditional experiments. Nowadays, computer represents an invaluable tool for chemists. In particular, the main topics of my research consisted in the development of an automated docking protocol for the voltage-gated hERG potassium channel blockers, and the investigation of the catalytic mechanism of the human peptidyl-prolyl cis-trans isomerase Pin1.

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15

Di, Martino Giovanni Paolo <1985&gt. "Computational Methods in Biophysics and Medicinal Chemistry: Applications and Challenges". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6329/.

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In this thesis I described the theory and application of several computational methods in solving medicinal chemistry and biophysical tasks. I pointed out to the valuable information which could be achieved by means of computer simulations and to the possibility to predict the outcome of traditional experiments. Nowadays, computer represents an invaluable tool for chemists. In particular, the main topics of my research consisted in the development of an automated docking protocol for the voltage-gated hERG potassium channel blockers, and the investigation of the catalytic mechanism of the human peptidyl-prolyl cis-trans isomerase Pin1.

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16

Cevenini, Luca <1981&gt. "Development of muliplexed analytical methods based on bioluminescent whole-cell biosensors". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/2910/1/Cevenini_Luca_Tesi.pdf.

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The subject of this Ph.D. research thesis is the development and application of multiplexed analytical methods based on bioluminescent whole-cell biosensors. One of the main goals of analytical chemistry is multianalyte testing in which two or more analytes are measured simultaneously in a single assay. The advantages of multianalyte testing are work simplification, high throughput, and reduction in the overall cost per test. The availability of multiplexed portable analytical systems is of particular interest for on-field analysis of clinical, environmental or food samples as well as for the drug discovery process. To allow highly sensitive and selective analysis, these devices should combine biospecific molecular recognition with ultrasensitive detection systems. To address the current need for rapid, highly sensitive and inexpensive devices for obtaining more data from each sample,genetically engineered whole-cell biosensors as biospecific recognition element were combined with ultrasensitive bioluminescence detection techniques. Genetically engineered cell-based sensing systems were obtained by introducing into bacterial, yeast or mammalian cells a vector expressing a reporter protein whose expression is controlled by regulatory proteins and promoter sequences. The regulatory protein is able to recognize the presence of the analyte (e.g., compounds with hormone-like activity, heavy metals…) and to consequently activate the expression of the reporter protein that can be readily measured and directly related to the analyte bioavailable concentration in the sample. Bioluminescence represents the ideal detection principle for miniaturized analytical devices and multiplexed assays thanks to high detectability in small sample volumes allowing an accurate signal localization and quantification. In the first chapter of this dissertation is discussed the obtainment of improved bioluminescent proteins emitting at different wavelenghts, in term of increased thermostability, enhanced emission decay kinetic and spectral resolution. The second chapter is mainly focused on the use of these proteins in the development of whole-cell based assay with improved analytical performance. In particular since the main drawback of whole-cell biosensors is the high variability of their analyte specific response mainly caused by variations in cell viability due to aspecific effects of the sample’s matrix, an additional bioluminescent reporter has been introduced to correct the analytical response thus increasing the robustness of the bioassays. The feasibility of using a combination of two or more bioluminescent proteins for obtaining biosensors with internal signal correction or for the simultaneous detection of multiple analytes has been demonstrated by developing a dual reporter yeast based biosensor for androgenic activity measurement and a triple reporter mammalian cell-based biosensor for the simultaneous monitoring of two CYP450 enzymes activation, involved in cholesterol degradation, with the use of two spectrally resolved intracellular luciferases and a secreted luciferase as a control for cells viability. In the third chapter is presented the development of a portable multianalyte detection system. In order to develop a portable system that can be used also outside the laboratory environment even by non skilled personnel, cells have been immobilized into a new biocompatible and transparent polymeric matrix within a modified clear bottom black 384 -well microtiter plate to obtain a bioluminescent cell array. The cell array was placed in contact with a portable charge-coupled device (CCD) light sensor able to localize and quantify the luminescent signal produced by different bioluminescent whole-cell biosensors. This multiplexed biosensing platform containing whole-cell biosensors was successfully used to measure the overall toxicity of a given sample as well as to obtain dose response curves for heavy metals and to detect hormonal activity in clinical samples (PCT/IB2010/050625: “Portable device based on immobilized cells for the detection of analytes.” Michelini E, Roda A, Dolci LS, Mezzanotte L, Cevenini L , 2010). At the end of the dissertation some future development steps are also discussed in order to develop a point of care (POCT) device that combine portability, minimum sample pre-treatment and highly sensitive multiplexed assays in a short assay time. In this POCT perspective, field-flow fractionation (FFF) techniques, in particular gravitational variant (GrFFF) that exploit the earth gravitational field to structure the separation, have been investigated for cells fractionation, characterization and isolation. Thanks to the simplicity of its equipment, amenable to miniaturization, the GrFFF techniques appears to be particularly suited for its implementation in POCT devices and may be used as pre-analytical integrated module to be applied directly to drive target analytes of raw samples to the modules where biospecifc recognition reactions based on ultrasensitive bioluminescence detection occurs, providing an increase in overall analytical output.

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17

Cevenini, Luca <1981&gt. "Development of muliplexed analytical methods based on bioluminescent whole-cell biosensors". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/2910/.

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The subject of this Ph.D. research thesis is the development and application of multiplexed analytical methods based on bioluminescent whole-cell biosensors. One of the main goals of analytical chemistry is multianalyte testing in which two or more analytes are measured simultaneously in a single assay. The advantages of multianalyte testing are work simplification, high throughput, and reduction in the overall cost per test. The availability of multiplexed portable analytical systems is of particular interest for on-field analysis of clinical, environmental or food samples as well as for the drug discovery process. To allow highly sensitive and selective analysis, these devices should combine biospecific molecular recognition with ultrasensitive detection systems. To address the current need for rapid, highly sensitive and inexpensive devices for obtaining more data from each sample,genetically engineered whole-cell biosensors as biospecific recognition element were combined with ultrasensitive bioluminescence detection techniques. Genetically engineered cell-based sensing systems were obtained by introducing into bacterial, yeast or mammalian cells a vector expressing a reporter protein whose expression is controlled by regulatory proteins and promoter sequences. The regulatory protein is able to recognize the presence of the analyte (e.g., compounds with hormone-like activity, heavy metals…) and to consequently activate the expression of the reporter protein that can be readily measured and directly related to the analyte bioavailable concentration in the sample. Bioluminescence represents the ideal detection principle for miniaturized analytical devices and multiplexed assays thanks to high detectability in small sample volumes allowing an accurate signal localization and quantification. In the first chapter of this dissertation is discussed the obtainment of improved bioluminescent proteins emitting at different wavelenghts, in term of increased thermostability, enhanced emission decay kinetic and spectral resolution. The second chapter is mainly focused on the use of these proteins in the development of whole-cell based assay with improved analytical performance. In particular since the main drawback of whole-cell biosensors is the high variability of their analyte specific response mainly caused by variations in cell viability due to aspecific effects of the sample’s matrix, an additional bioluminescent reporter has been introduced to correct the analytical response thus increasing the robustness of the bioassays. The feasibility of using a combination of two or more bioluminescent proteins for obtaining biosensors with internal signal correction or for the simultaneous detection of multiple analytes has been demonstrated by developing a dual reporter yeast based biosensor for androgenic activity measurement and a triple reporter mammalian cell-based biosensor for the simultaneous monitoring of two CYP450 enzymes activation, involved in cholesterol degradation, with the use of two spectrally resolved intracellular luciferases and a secreted luciferase as a control for cells viability. In the third chapter is presented the development of a portable multianalyte detection system. In order to develop a portable system that can be used also outside the laboratory environment even by non skilled personnel, cells have been immobilized into a new biocompatible and transparent polymeric matrix within a modified clear bottom black 384 -well microtiter plate to obtain a bioluminescent cell array. The cell array was placed in contact with a portable charge-coupled device (CCD) light sensor able to localize and quantify the luminescent signal produced by different bioluminescent whole-cell biosensors. This multiplexed biosensing platform containing whole-cell biosensors was successfully used to measure the overall toxicity of a given sample as well as to obtain dose response curves for heavy metals and to detect hormonal activity in clinical samples (PCT/IB2010/050625: “Portable device based on immobilized cells for the detection of analytes.” Michelini E, Roda A, Dolci LS, Mezzanotte L, Cevenini L , 2010). At the end of the dissertation some future development steps are also discussed in order to develop a point of care (POCT) device that combine portability, minimum sample pre-treatment and highly sensitive multiplexed assays in a short assay time. In this POCT perspective, field-flow fractionation (FFF) techniques, in particular gravitational variant (GrFFF) that exploit the earth gravitational field to structure the separation, have been investigated for cells fractionation, characterization and isolation. Thanks to the simplicity of its equipment, amenable to miniaturization, the GrFFF techniques appears to be particularly suited for its implementation in POCT devices and may be used as pre-analytical integrated module to be applied directly to drive target analytes of raw samples to the modules where biospecifc recognition reactions based on ultrasensitive bioluminescence detection occurs, providing an increase in overall analytical output.

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Jia, Yiming <1988&gt. "Exploring New Material and Analytical Method for Characterization and Conservation of Artifacts". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amsdottorato.unibo.it/9367/1/Thesis-Jiayiming-32cycle-Chemistry.pdf.

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In this dissertation, we focus on developing new green bio-based gel systems and evaluating both the cleaning efficiency and the release of residues on the treated surface, different micro or no destructive techniques, such as optical microscopy, TGA, FTIR spectroscopy, HS-SPME and micro-Spatially Offset Raman spectroscopy (micro-SORS) were tested, proposing advanced analytical protocols. In the first part, a ternary PHB-DMC/BD gel system composed by biodiesel, dimethyl carbonate and poly-3 hydroxybutyrate was developed for cleaning of wax-based coatings applied on indoor bronze. The evaluation of the cleaning efficacy of the gel was carried out on a standard bronze sample which covered a layer of beeswax by restores of Opificio delle Pietre Dure in Florence, and a real case precious indoor bronze sculpture Pulpito della Passione attributed to Donatello. Results obtained by FTIR analysis showed an efficient removal of the wax coating. In the second part, two new kinds of combined gels based on electrospun tissues (PVA and nylon) and PHB-GVL gel were developed for removal of dammar varnish from painting. The electrospun tissue combined gels exhibited good mechanical property, and showed good efficient in cleaning over normal gel. In the third part, green deep eutectic solvent which consists urea and choline chloride was proposed to produce the rigid gel with agar for the removal of proteinaceous coating from oil painting. Rabbit glue and whole egg decorated oil painting mock-ups were selected for evaluating its cleaning efficiency, results obtained by ATR analysis showed the DES-agar gel has good cleaning performance. Furthermore, we proposed micro-SORS as a valuable alternative non-destructive method to explore the DES diffusion on painting mock-up. As a result, the micro-SORS was successful applied for monitoring the liquid diffusion behavior in painting sub-layer, providing a great and useful instrument for noninvasive residues detection in the conservation field.

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19

Rossetto, Nicola. "Materials and methods for modular microfluidic devices". Doctoral thesis, Università degli studi di Padova, 2013. http://hdl.handle.net/11577/3422583.

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This thesis work concerns the investigation of materials and methods that can be applied to the realization of microfluidic devices (MFDs). In particular, the attention is placed on modular MFDs, as opposed to fully integrated ones. The reasons behind this choice are given in detail in Section 1.2 of this work, but they can be here summarized in the fact that while integrated MFDs offer great advantages in terms of portability, modular devices are more versatile, and so particularly well suited for research applications. The first part of the work here reported describes the microfabrication techniques employed for the realization of single-function microfluidic modules. Devices have been fabricated through PDMS replica molding from SU-8 masters. Masters have been in turn realized through masked UV-lithography or one- or two-photon direct laser writing, depending on the resolution requirements. The replica molding method is a very fast and efficient way to realize MFDs, but suffers from some limitations in the structure shapes that can be successfully replicated. In light of this, a photopolymerizable hybrid organic/inorganic sol-gel blend is proposed and tested as alternative material for MFDs fabrication. The characterization results reveal that this material is biocompatible and features better mechanical properties than PDMS, but structures with more than one dimension exceeding a few micrometers tend to crack during fabrication, making this blend unusable as bulk material. Still, this material could be efficiently employed to fabricate sub-structuration inside PDMS channels. Following this investigation on materials, a microfluidic mixing module is proposed and tested. Since laminar flow conditions dominate inside microchannels, efficient mixing in MFDs require the use of specifically designed mixers. The proposed module makes use of obstructions inside a microchannel to perturb the laminar flow and thus enhance mixing of two species. The most efficient geometries have been selected with the aid of numerical simulations, and two promising layouts have been fabricated and experimentally tested by measuring the dilution of a fluorophore (mixing between a fluorophore solution and pure solvent) through confocal fluorescence microscopy. Thirdly, the fabrication and characterization of an optofluidic light switching module is reported. This device employs a water/air segmented flow generated by a T-junction to alternatively transmit or total-reflect a laser beam. This deflection is proved to be periodical, and its frequency can be varied nonlinearly by adjusting the injection flow rates of air and water. The duty cycle of the module is also characterized, and a method to modulate it by increasing the water temperature is proposed and verified. Finally, a number of attempts to generate a nanoporous, low refractive index PDMS are described. The identification of an efficient procedure to fabricate this kind of material would lead to the possibility of using common microfluidic channels as water-core waveguides. To date, these attempts have not been totally successful, but critical points are identified, and viable strategies for future works on the subject are proposed.
Questo lavoro di tesi tratta dello studio di materiali e metodi che possono essere applicati alla realizzazione di dispositivi microfluidici (DMF). In particolare l’attenzione è rivolta ai dispositivi modulari, piuttosto che a quelli altamente integrati. Le ragioni dietro questa scelta sono spiegate in dettaglio nella Sezione 1.2 di questa tesi, ma possono essere qui sintetizzate nel fatto che anche se i DMF integrati offrono grandi vantaggi in termini di dimensioni finali, i dispositivi modulari sono più versatili, e quindi particolarmente utili per applicazioni nel campo della ricerca. La prima parte del lavoro qui riportato descrive le tecniche di microfabbricazione utilizzate per la realizzazione di moduli microfluidici monofunzionali. I dispositivi sono stati realizzati per replica molding in PDMS a partire da master in SU-8. I master sono stati a loro volta fabbricati tramite litografia UV con maschera oppure per scrittura laser diretta ad uno o due fotoni, a seconda dei requisiti di risoluzione. Il replica molding è un metodo molto rapido ed efficiente per realizzare DMF, ma presenta alcuni limiti per quanto riguarda la forma delle strutture che è possibile replicare con successo. Alla luce di questo, un sol-gel fotopolimerizzabile ibrido organico/inorganico viene qui proposto e testato come materiale alternativo per la fabbricazione di DMF. I risultati della caratterizzazione rivelano che questo materiale è biocompatibile e presenta proprietà meccaniche migliori di quelle del PDMS, ma strutture con più di una dimensione eccedente i pochi micrometri tendono a sviluppare cricche, cosa che impedisce l’utilizzo di questo sol-gel come materiale massivo. Ciononostante, questo sol-gel potrebbe venir efficacemente impiegato per la realizzazione di sottostrutturazioni all’interno di canali microfluidici. Dopo questo studio sui materiali, un modulo microfluidico per il mescolamento è proposto e testato. Dato che le condizioni di flusso laminare sono dominanti all’interno dei microcanali, per ottenere un mescolamento efficiente in un DMF è necessario includere nel dispositivo un miscelatore specificatamente progettato. Il modulo proposto utilizza delle ostruzioni all’interno del microcanale per perturbare il flusso laminare e quindi favorire il mescolamento. Con l’aiuto di alcune simulazioni numeriche, le geometrie più efficienti sono state individuate, e due layout particolarmente promettenti sono stati realizzati e caratterizzati sperimentalmente misurando la diluizione di un fluoroforo (mescolamento tra una soluzione del fluoroforo e puro solvente) attraverso la microscopia confocale di fluorescenza. A seguire, viene riportata la fabbricazione e caratterizzazione di un modulo optofluidico per la deflessione della luce. Questo dispositivo utilizza un flusso segmentato acqua/aria generato da una giunzione a T per trasmettere o riflettere (per riflessione totale interna) alternativamente un fascio laser. Questa alternanza è periodica, e la sua frequenza può essere controllata variando la portata dei flussi iniettati di aria e acqua. Inoltre, il duty cycle del modulo è stato caratterizzato, e viene proposto e verificato un metodo per modularlo attraverso un aumento della temperatura dell’acqua. Infine, vengono descritti alcuni tentativi di generare un PDMS nanoporoso con basso indice di rifrazione. La messa a punto di una procedura efficiente per la fabbricazione di questo genere di materiale porterebbe alla possibilità di usare i classici canali microfluidici come guide d’onda. Al momento questi tentativi hanno avuto solo parziale successo, ma i maggiori punti di criticità sono stati identificati, e vengono proposte alcune strategie per il loro futuro superamento.

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20

Musenga, Alessandro <1975&gt. "Innovative analytical methods for Central Nervous System Drug analysis in biological fluids". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amsdottorato.unibo.it/1448/1/Alessandro_musenga_tesi.pdf.

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During recent years a consistent number of central nervous system (CNS) drugs have been approved and introduced on the market for the treatment of many psychiatric and neurological disorders, including psychosis, depression, Parkinson disease and epilepsy. Despite the great advancements obtained in the treatment of CNS diseases/disorders, partial response to therapy or treatment failure are frequent, at least in part due to poor compliance, but also genetic variability in the metabolism of psychotropic agents or polypharmacy, which may lead to sub-therapeutic or toxic plasma levels of the drugs, and finally inefficacy of the treatment or adverse/toxic effects. With the aim of improving the treatment, reducing toxic/side effects and patient hospitalisation, Therapeutic Drug Monitoring (TDM) is certainly useful, allowing for a personalisation of the therapy. Reliable analytical methods are required to determine the plasma levels of psychotropic drugs, which are often present at low concentrations (tens or hundreds of nanograms per millilitre). The present PhD Thesis has focused on the development of analytical methods for the determination of CNS drugs in biological fluids, including antidepressants (sertraline and duloxetine), antipsychotics (aripiprazole), antiepileptics (vigabatrin and topiramate) and antiparkinsons (pramipexole). Innovative methods based on liquid chromatography or capillary electrophoresis coupled to diode-array or laser-induced fluorescence detectors have been developed, together with the suitable sample pre-treatment for interference removal and fluorescent labelling in case of LIF detection. All methods have been validated according to official guidelines and applied to the analysis of real samples obtained from patients, resulting suitable for the TDM of psychotropic drugs.

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21

Musenga, Alessandro <1975&gt. "Innovative analytical methods for Central Nervous System Drug analysis in biological fluids". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amsdottorato.unibo.it/1448/.

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During recent years a consistent number of central nervous system (CNS) drugs have been approved and introduced on the market for the treatment of many psychiatric and neurological disorders, including psychosis, depression, Parkinson disease and epilepsy. Despite the great advancements obtained in the treatment of CNS diseases/disorders, partial response to therapy or treatment failure are frequent, at least in part due to poor compliance, but also genetic variability in the metabolism of psychotropic agents or polypharmacy, which may lead to sub-therapeutic or toxic plasma levels of the drugs, and finally inefficacy of the treatment or adverse/toxic effects. With the aim of improving the treatment, reducing toxic/side effects and patient hospitalisation, Therapeutic Drug Monitoring (TDM) is certainly useful, allowing for a personalisation of the therapy. Reliable analytical methods are required to determine the plasma levels of psychotropic drugs, which are often present at low concentrations (tens or hundreds of nanograms per millilitre). The present PhD Thesis has focused on the development of analytical methods for the determination of CNS drugs in biological fluids, including antidepressants (sertraline and duloxetine), antipsychotics (aripiprazole), antiepileptics (vigabatrin and topiramate) and antiparkinsons (pramipexole). Innovative methods based on liquid chromatography or capillary electrophoresis coupled to diode-array or laser-induced fluorescence detectors have been developed, together with the suitable sample pre-treatment for interference removal and fluorescent labelling in case of LIF detection. All methods have been validated according to official guidelines and applied to the analysis of real samples obtained from patients, resulting suitable for the TDM of psychotropic drugs.

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22

Lanza, Tommaso <1979&gt. "Innovative methods for the generation and synthetic applications of organic free-radicals". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/2958/1/Lanza_Tommaso_tesi.pdf.

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23

Lanza, Tommaso <1979&gt. "Innovative methods for the generation and synthetic applications of organic free-radicals". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/2958/.

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24

Morganti, Emanuele <1980&gt. "Original analytical methods for the determination of psychoactive compounds in complex matrices". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/7189/1/morganti_emanuele_tesi_.pdf.

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This thesis work aims to develop original analytical methods for the determination of drugs with a potential for abuse, for the analysis of substances used in the pharmacological treatment of drug addiction in biological samples and for the monitoring of potentially toxic compounds added to street drugs. In fact reliable analytical techniques can play an important role in this setting. They can be employed to reveal drug intake, allowing the identification of drug users and to assess drug blood levels, assisting physicians in the management of the treatment. Pharmacological therapy needs to be carefully monitored indeed in order to optimize the dose scheduling according to the specific needs of the patient and to discourage improper use of the medication. In particular, different methods have been developed for the detection of gamma-hydroxybutiric acid (GHB), prescribed for the treatment of alcohol addiction, of glucocorticoids, one of the most abused pharmaceutical class to enhance sport performance and of adulterants, pharmacologically active compounds added to illicit drugs for recreational purposes. All the presented methods are based on capillary electrophoresis (CE) and high performance liquid chromatography (HPLC) coupled to various detectors (diode array detector, mass spectrometer). Biological samples pre-treatment was carried out using different extraction techniques, liquid-liquid extraction (LLE) and solid phase extraction (SPE). Different matrices have been considered: human plasma, dried blood spots, human urine, simulated street drugs. These developed analytical methods are individually described and discussed in this thesis work.

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25

Morganti, Emanuele <1980&gt. "Original analytical methods for the determination of psychoactive compounds in complex matrices". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/7189/.

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This thesis work aims to develop original analytical methods for the determination of drugs with a potential for abuse, for the analysis of substances used in the pharmacological treatment of drug addiction in biological samples and for the monitoring of potentially toxic compounds added to street drugs. In fact reliable analytical techniques can play an important role in this setting. They can be employed to reveal drug intake, allowing the identification of drug users and to assess drug blood levels, assisting physicians in the management of the treatment. Pharmacological therapy needs to be carefully monitored indeed in order to optimize the dose scheduling according to the specific needs of the patient and to discourage improper use of the medication. In particular, different methods have been developed for the detection of gamma-hydroxybutiric acid (GHB), prescribed for the treatment of alcohol addiction, of glucocorticoids, one of the most abused pharmaceutical class to enhance sport performance and of adulterants, pharmacologically active compounds added to illicit drugs for recreational purposes. All the presented methods are based on capillary electrophoresis (CE) and high performance liquid chromatography (HPLC) coupled to various detectors (diode array detector, mass spectrometer). Biological samples pre-treatment was carried out using different extraction techniques, liquid-liquid extraction (LLE) and solid phase extraction (SPE). Different matrices have been considered: human plasma, dried blood spots, human urine, simulated street drugs. These developed analytical methods are individually described and discussed in this thesis work.

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26

Pecchielan, Giulia <1985&gt. "Development of analytes' screening methods using voltammetric techniques and scanning electrochemical microscopy". Doctoral thesis, Università Ca' Foscari Venezia, 2015. http://hdl.handle.net/10579/8290.

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I numerosi vantaggi offerti dalla Microscopia Elettrochimica a Scansione (SECM) e dalle tecniche microcapillari (MC), hanno visto un grande interesse nello sviluppo di queste tecniche per studiare e caratterizzare una grande varietà di materiali all’interfase substrato/soluzione. Le tecniche vengono anche ampiamente utilizzate per modificare le superfici con funzionalità specifiche. In questa tesi, la SECM e la MC sono state usate per studiare fenomeni chimici che avvengono all’interfase solido/soluzione di sistemi costituiti da nano particelle di argento (AgNPs). Nella tesi, in particolare, sono presentate alcune strategie per fabbricare/caratterizzare le AgNPS. Lo studio è stato rivolto anche a materiali contenti AgNPs disponibili in commercio. Per razionalizzare alcuni risultati sperimentali ottenuti con la tecnica MC, è stata presentata e discussa un approccio teorico, basato sui metodi di simulazione digitale, mai riportato in precedenza in letteratura, per stabilire i fenomeni di trasporto di massa che si realizzano nella micro pipetta, il cui menisco è in contatto con un substrato conduttore recesso. Lo stato redox di Ag presente nelle AgNPS e la reattività locale delle AgNPS, incorporate in matrici solide o soft, quali Nafion®, esopolisaccaridi, poliammide e beni disponibili in commercio sono stati studiati utilizzando SECM e la voltammetria nella versione stripping. A causa delle peculiari proprietà chimico-fisiche e biologiche, le AgNPS rivestono interesse in quanto esse vengono utilizzate come sostanze antibatteriche. L'azione antibatterica di AgNPS sembra dipendere dalla quantità e cinetica di Ag+ rilasciata nei mezzi con esse a contatto. Le misure di rilascio sono state eseguite dopo aver immerso i substrati contenenti AgNPs in miscele acqua o acqua / etanolo. Queste miscele sono usate per simulare il comportamento di matrici alimentari. Infine, allo scopo di promuovere l'uso di nuovi materiali nanostrutturati nella tecnologia dei sensori, è stata effettuata un'indagine per stabilire le proprietà di ossidi grafene ridotto (GOs), preparati con una tecnica pressure/wax-based transferring, da utilizzare come materiali elettrodici. Strati sottili di GO sono stati depositati sotto forma di array di elettrodi a banda e quindi sono stati sottoposti ad indagine mediante SECM e voltammetria.

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27

Carnimeo, Ivan. "Computational methods for spectroscopic properties". Doctoral thesis, Scuola Normale Superiore, 2014. http://hdl.handle.net/11384/85802.

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28

Tartagni, Ottavia <1992&gt. "Advanced cell culture platforms: methods for drug testing with microfluidics and microstructured devices". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2022. http://amsdottorato.unibo.it/10234/1/Tartagni_Ottavia_Advanced%20cell%20culture%20platforms%20methods%20for%20drug%20testing.pdf.

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Advanced cell cultures are developing rapidly in biomedical research. Nowadays, various approaches and technologies are being used, however, these culturing systems present limitations from increasing complexity, requiring high costs, and not easily customization. We present two versatile and cost-effective methods for developing culturing systems that integrate 3D cell culture and microfluidic platforms. Firstly, for drug screening applications, many high-quality cell spheres of homogeneous size and shape are required. Conventional approaches usually have a dearth of control over the size and geometry of cell spheres and require sample collection and manipulation. To overcome this difficulty, in this study, hundreds of spheroids of several cell lines were generated using multi-well plates that housed our microdevices. Tumor spheroids grow at a uniform rate (in scaffolded or scaffold-free environments) and can be harvested at will. Microscopy imaging are done in real time during or after the culture. After in situ immunostaining, fluorescence imaging can be conducted while keeping the spatial distribution of spheroids in the microwells. Drug effects were successfully observed through viability, growth, and morphologic investigations. Also, we fabricated a microfluidic device suitable for directed and selective cell culture treatments. The microfluidic device was used to reproduce and confirm in vitro investigations carried out using normal culture methods, using a microglia cell line. The device layout and the syringe pump system, entirely designed in our lab, successfully allowed culture growth and medium flow regulation. Solution flows can be finely controlled, allowing treatments and immunofluorescence in one single chamber selectively. To conclude, we propose the development of two culturing platforms (microstructured well devices and in-flow microfluidic chip), which are the result of separate scientific investigations but have the primary goal of performing treatments in a reproducible manner. Our devices shall improve future studies on drug exposure testing, representing adjustable and versatile cell culture systems.

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29

Burgay, Francois Yves <1989&gt. "Development and application of new methods to perform iron speciation in ice cores". Doctoral thesis, Università Ca' Foscari Venezia, 2018. http://hdl.handle.net/10579/14963.

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Volcanic eruptions are widely used in ice core science to date or synchronize ice cores. Volcanoes emit large amounts of SO2 that is subsequently converted in the atmosphere into sulfuric acid and finally into sulphate. Its discrete and continuous quantification is currently used to determine the ice layers impacted by volcanic emissions. However, these methods struggle to achieve the sensitivity and the limits of detection needed for deep polar ice analyses. Volcanoes emit a wide variety of other chemical compounds, including large quantities of soluble and bioavailable iron which, especially at the low pH values of the volcanic aerosol, is present as Fe2+. Here, we present a new high-resolution method for the continuous determination of Fe2+ species in ice cores. The method, applied on a Greenland ice core, correctly identifies all volcanic eruptions from between 1588 to 1611 and from 1777 to 1850. The method has a detection limit of ∽5 pg g–1 and a quadratic polynomial calibration range of up to at least 1760 pg g–1. Our results show that Fe2+ is a suitable proxy for identifying past volcanic events.

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30

Fadanni, Jacopo <1994&gt. "Noises: a Nuisance and a Resource. Development of New Decomposition Methods of Noisy Data". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2022. http://amsdottorato.unibo.it/10309/1/Thesis_Fadanni_Jacopo.pdf.

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Noise is constant presence in measurements. Its origin is related to the microscopic properties of matter. Since the seminal work of Brown in 1828, the study of stochastic processes has gained an increasing interest with the development of new mathematical and analytical tools. In the last decades, the central role that noise plays in chemical and physiological processes has become recognized. The dual role of noise as nuisance/resource pushes towards the development of new decomposition techniques that divide a signal into its deterministic and stochastic components. In this thesis I show how methods based on Singular Spectrum Analysis have the right properties to fulfil the previously mentioned requirement. During my work I applied SSA to different signals of interest in chemistry: I developed a novel iterative procedure for the denoising of powder X-ray diffractograms; I “denoised” bi-dimensional images from experiments of electrochemiluminescence imaging of micro-beads obtaining new insight on ECL mechanism. I also used Principal Component Analysis to investigate the relationship between brain electrophysiological signals and voice emission.

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31

Locritani, Mirko <1983&gt. "Development of synthetic methods of silicon nanocrystals functionalized with photoactive molecules". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/7016/1/Locritani_Mirko_tesi.pdf.

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The thesis is focused on the development of a method for the synthesis of silicon nanocrystals with different sizes, narrow size distribution, good optical properties and stability in air. The resulting silicon nanocrystals have been covalently functionalized with different chromophores with the aim to exploit the new electronic and chemical properties that emerge from the interaction between silicon nanocrystal surface and ligands. The purpose is to use these chromophores as light harvesting antennae, increasing the optical absorption of silicon nanocrystals. Functionalized silicon nanocrystals have been characterized with different analytical techniques leading to a good knowledge of optical properties of semiconductor quantum dots.

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32

Locritani, Mirko <1983&gt. "Development of synthetic methods of silicon nanocrystals functionalized with photoactive molecules". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/7016/.

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The thesis is focused on the development of a method for the synthesis of silicon nanocrystals with different sizes, narrow size distribution, good optical properties and stability in air. The resulting silicon nanocrystals have been covalently functionalized with different chromophores with the aim to exploit the new electronic and chemical properties that emerge from the interaction between silicon nanocrystal surface and ligands. The purpose is to use these chromophores as light harvesting antennae, increasing the optical absorption of silicon nanocrystals. Functionalized silicon nanocrystals have been characterized with different analytical techniques leading to a good knowledge of optical properties of semiconductor quantum dots.

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33

OUMAROU, AMADOU AMADOU. "SELECTIVE SUSTAINABLE COBALT RECOVERING METHODS FROM HARDMETAL PRODUCTION BY-PRODUCTS". Doctoral thesis, Università degli Studi di Cagliari, 2020. http://hdl.handle.net/11584/294327.

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The aim of the present work is to study new sustainable solvometallurgical routes for the selective Co-leaching from WC-Co-based "HardMetals" (HM) recovery powders, with the view to turn these hazardous by-products of the HM manufacturing process in valued secondary materials to be directly re-employed for industrial purposes. An overview on HM, their peculiar properties as well as the criticalities related to their main constituents, W and Co, is provided in Chapter 1, besides the green chemistry-based approach this thesis would like to follow for pursuing the scope of a sustainable and profitable circular economy model in HM manufacturing, through the identification of sustainable leaching systems (PART I) and the design of sustainable processes for industrial application (PART II). Bio-derived organic acids for hydrometallurgy are described in Chapter 2. They are classified on the bases of the oxidizing specie involved in leaching process (H+ or O2) and tested on Co-metal powder as well as on the HM test specimens. Several of them demonstrated high leaching efficiency and selectivity in Co-dissolution from WC-Co powders, preserving WC for following application. A selection of acids working in non-water solvents like alcohols were studied in Chapter 3, maleic acid ethanolic solutions showing to be the most interesting for solvometallurgy. Chapter 4 investigates soft- and hard-donor ligand-based solvometallurgy in the presence of iodine as external, recyclable and safe oxidizing agent. S-donor organic ligand/I2 systems demonstrated to be the most powerful with Co-leaching times significantly shorter than those found in acidic-solvometallurgy. Very promising was lactate/I2 system that coupled high effectiveness and sustainability being based on the use of a low cost, biodegradable and bio-derived ligand. On the bases of the obtained results of PART I, PART II - Chapter 5 reports the scale-up of lactic, succinic and maleic acid-based leaching processes as well as the preliminary results on materials recovery for applicative HM production. Besides the confirmation of leaching efficiency and selectivity towards Co, the chapter points out the high quality of the recovered materials, prone to be used for industrial purposes. Supported by the successful experimentation, attempts of designing sustainable and profitable circular economy models in HM manufacturing, based on the use of dairy waste as source of lactic acid both for hydro- and solvo-metallurgical treatments, are proposed and discussed in Chapter 6 in the light of the idea that the greater the sustainability the greater the profitability of the model. The overall conclusions of the thesis are finally discussed in Chapter 7.

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34

Destefani, Marco <1996&gt. "Development of electrochemical methods for desalination of porous materials". Master's Degree Thesis, Università Ca' Foscari Venezia, 2021. http://hdl.handle.net/10579/20291.

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L'obiettivo della tesi è quello di ricercare efficaci metodi elettrochimici che possano essere utilizzati per ipotetiche operazioni di desalinizzazione e consolidamento di supporti lapidei. Tramite l'impiego di un sistema ad elettrodi artigianale realizzato in laboratorio, durante l'esperienza si eseguiranno sperimentazioni su supporti lapidei di varia natura. Da questi esperimenti si potrà notare l'efficacia del sistema in seguito al trattamento di materiali dalla diversa composizione chimica, fornendo importanti dati per eventuali migliorie nel campo della pulitura di materiali lapidei porosi della conservazione dei beni culturali.

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35

LANGASCO, ILARIA. "Toxic and trace elements in rice: analytical methods, bioconcentration, influence of irrigation techniques". Doctoral thesis, Università degli Studi di Cagliari, 2021. http://hdl.handle.net/11584/306898.

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The principal theme of this PhD thesis is focused on the effect that changes on the nature of the irrigation method of rice play on the bioaccumulation of some toxic elements (As, Cd, Cr, Sb, Hg, Pb, and Tl) or potentially toxic oligoelements (Al, Cu, Fe, Mn, Mo, Ni, Se, and Zn) in rice kernels. The bioaccumulation of harmful elements in rice grain is the most threatening reason of health concern for the strong consumers of this staple food for mankind. Three different irrigation methods have been considered (continuous flooding, periodical saturation, and sprinkler irrigation) as well as soils of different geopedological nature and pollution levels. Also, the effect has been evaluated on a large number of rice genotypes. The main goal reached is to find out the possibility that, working only on the nature of the irrigation method of the rice plant, it is possible to get environmentally friendly rice, characterized by both a smallest concentration of toxic elements and the highest level of food safety.

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36

Rambaldi, Diana Cristina <1981&gt. "Analytical challenges in the fields of Nanobioscience and Nanobiotecnology: integrated methods for separation and characterization". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/2900/1/Diana_Rambaldi_Tesi.pdf.

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Nano(bio)science and nano(bio)technology play a growing and tremendous interest both on academic and industrial aspects. They are undergoing rapid developments on many fronts such as genomics, proteomics, system biology, and medical applications. However, the lack of characterization tools for nano(bio)systems is currently considered as a major limiting factor to the final establishment of nano(bio)technologies. Flow Field-Flow Fractionation (FlFFF) is a separation technique that is definitely emerging in the bioanalytical field, and the number of applications on nano(bio)analytes such as high molar-mass proteins and protein complexes, sub-cellular units, viruses, and functionalized nanoparticles is constantly increasing. This can be ascribed to the intrinsic advantages of FlFFF for the separation of nano(bio)analytes. FlFFF is ideally suited to separate particles over a broad size range (1 nm-1 μm) according to their hydrodynamic radius (rh). The fractionation is carried out in an empty channel by a flow stream of a mobile phase of any composition. For these reasons, fractionation is developed without surface interaction of the analyte with packing or gel media, and there is no stationary phase able to induce mechanical or shear stress on nanosized analytes, which are for these reasons kept in their native state. Characterization of nano(bio)analytes is made possible after fractionation by interfacing the FlFFF system with detection techniques for morphological, optical or mass characterization. For instance, FlFFF coupling with multi-angle light scattering (MALS) detection allows for absolute molecular weight and size determination, and mass spectrometry has made FlFFF enter the field of proteomics. Potentialities of FlFFF couplings with multi-detection systems are discussed in the first section of this dissertation. The second and the third sections are dedicated to new methods that have been developed for the analysis and characterization of different samples of interest in the fields of diagnostics, pharmaceutics, and nanomedicine. The second section focuses on biological samples such as protein complexes and protein aggregates. In particular it focuses on FlFFF methods developed to give new insights into: a) chemical composition and morphological features of blood serum lipoprotein classes, b) time-dependent aggregation pattern of the amyloid protein Aβ1-42, and c) aggregation state of antibody therapeutics in their formulation buffers. The third section is dedicated to the analysis and characterization of structured nanoparticles designed for nanomedicine applications. The discussed results indicate that FlFFF with on-line MALS and fluorescence detection (FD) may become the unparallel methodology for the analysis and characterization of new, structured, fluorescent nanomaterials.

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37

Rambaldi, Diana Cristina <1981&gt. "Analytical challenges in the fields of Nanobioscience and Nanobiotecnology: integrated methods for separation and characterization". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/2900/.

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Nano(bio)science and nano(bio)technology play a growing and tremendous interest both on academic and industrial aspects. They are undergoing rapid developments on many fronts such as genomics, proteomics, system biology, and medical applications. However, the lack of characterization tools for nano(bio)systems is currently considered as a major limiting factor to the final establishment of nano(bio)technologies. Flow Field-Flow Fractionation (FlFFF) is a separation technique that is definitely emerging in the bioanalytical field, and the number of applications on nano(bio)analytes such as high molar-mass proteins and protein complexes, sub-cellular units, viruses, and functionalized nanoparticles is constantly increasing. This can be ascribed to the intrinsic advantages of FlFFF for the separation of nano(bio)analytes. FlFFF is ideally suited to separate particles over a broad size range (1 nm-1 μm) according to their hydrodynamic radius (rh). The fractionation is carried out in an empty channel by a flow stream of a mobile phase of any composition. For these reasons, fractionation is developed without surface interaction of the analyte with packing or gel media, and there is no stationary phase able to induce mechanical or shear stress on nanosized analytes, which are for these reasons kept in their native state. Characterization of nano(bio)analytes is made possible after fractionation by interfacing the FlFFF system with detection techniques for morphological, optical or mass characterization. For instance, FlFFF coupling with multi-angle light scattering (MALS) detection allows for absolute molecular weight and size determination, and mass spectrometry has made FlFFF enter the field of proteomics. Potentialities of FlFFF couplings with multi-detection systems are discussed in the first section of this dissertation. The second and the third sections are dedicated to new methods that have been developed for the analysis and characterization of different samples of interest in the fields of diagnostics, pharmaceutics, and nanomedicine. The second section focuses on biological samples such as protein complexes and protein aggregates. In particular it focuses on FlFFF methods developed to give new insights into: a) chemical composition and morphological features of blood serum lipoprotein classes, b) time-dependent aggregation pattern of the amyloid protein Aβ1-42, and c) aggregation state of antibody therapeutics in their formulation buffers. The third section is dedicated to the analysis and characterization of structured nanoparticles designed for nanomedicine applications. The discussed results indicate that FlFFF with on-line MALS and fluorescence detection (FD) may become the unparallel methodology for the analysis and characterization of new, structured, fluorescent nanomaterials.

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38

Marcheselli, Chiara <1981&gt. "Development of Original Analytical Methods for the Determination of Drugs of Abuse in Biological Samples". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amsdottorato.unibo.it/4710/1/marcheselli_chiara_tesi.pdf.

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Drug abuse is a major global problem which has a strong impact not only on the single individual but also on the entire society. Among the different strategies that can be used to address this issue an important role is played by identification of abusers and proper medical treatment. This kind of therapy should be carefully monitored in order to discourage improper use of the medication and to tailor the dose according to the specific needs of the patient. Hence, reliable analytical methods are needed to reveal drug intake and to support physicians in the pharmacological management of drug dependence. In the present Ph.D. thesis original analytical methods for the determination of drugs with a potential for abuse and of substances used in the pharmacological treatment of drug addiction are presented. In particular, the work has been focused on the analysis of ketamine, naloxone and long-acting opioids (buprenorphine and methadone), oxycodone, disulfiram and bupropion in human plasma and in dried blood spots. The developed methods are based on the use of high performance liquid chromatography (HPLC) coupled to various kinds of detectors (mass spectrometer, coulometric detector, diode array detector). For biological sample pre-treatment different techniques have been exploited, namely solid phase extraction and microextraction by packed sorbent. All the presented methods have been validated according to official guidelines with good results and some of these have been successfully applied to the therapeutic drug monitoring of patients under treatment for drug abuse.

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39

Marcheselli, Chiara <1981&gt. "Development of Original Analytical Methods for the Determination of Drugs of Abuse in Biological Samples". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amsdottorato.unibo.it/4710/.

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Drug abuse is a major global problem which has a strong impact not only on the single individual but also on the entire society. Among the different strategies that can be used to address this issue an important role is played by identification of abusers and proper medical treatment. This kind of therapy should be carefully monitored in order to discourage improper use of the medication and to tailor the dose according to the specific needs of the patient. Hence, reliable analytical methods are needed to reveal drug intake and to support physicians in the pharmacological management of drug dependence. In the present Ph.D. thesis original analytical methods for the determination of drugs with a potential for abuse and of substances used in the pharmacological treatment of drug addiction are presented. In particular, the work has been focused on the analysis of ketamine, naloxone and long-acting opioids (buprenorphine and methadone), oxycodone, disulfiram and bupropion in human plasma and in dried blood spots. The developed methods are based on the use of high performance liquid chromatography (HPLC) coupled to various kinds of detectors (mass spectrometer, coulometric detector, diode array detector). For biological sample pre-treatment different techniques have been exploited, namely solid phase extraction and microextraction by packed sorbent. All the presented methods have been validated according to official guidelines with good results and some of these have been successfully applied to the therapeutic drug monitoring of patients under treatment for drug abuse.

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40

D’Agostino, Simone <1981&gt. "Preparation of new crystal forms via photochemical, mechanochemical and sol-gel methods". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amsdottorato.unibo.it/4650/1/dagostino_simone_tesi.pdf.

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This work of thesis involves various aspects of crystal engineering. Chapter 1 focuses on crystals containing crown ether complexes. Aspects such as the possibility of preparing these materials by non-solution methods, i.e. by direct reaction of the solid components, thermal behavior and also isomorphism and interconversion between hydrates are taken into account. In chapter 2 a study is presented aimed to understanding the relationship between hydrogen bonding capability and shape of the building blocks chosen to construct crystals. The focus is on the control exerted by shape on the organization of sandwich cations such as cobalticinium, decamethylcobalticinium and bisbenzenchromium(I) and on the aggregation of monoanions all containing carboxylic and carboxylate groups, into 0-D, 1-D, 2-D and 3-D networks. Reactions conducted in multi-component molecular assemblies or co-crystals have been recognized as a way to control reactivity in the solid state. The [2+2] photodimerization of olefins is a successful demonstration of how templated solid state synthesis can efficiently synthesize unique materials with remarkable stereoselectivity and under environment-friendly conditions. A demonstration of this synthetic strategy is given in chapter 3. The combination of various types of intermolecular linkages, leading to formation of high order aggregation and crystalline materials or to a random aggregation resulting in an amorphous precipitate, may not go to completeness. In such rare cases an aggregation process intermediate between crystalline and amorphous materials is observed, resulting in the formation of a gel, i.e. a viscoelastic solid-like or liquid-like material. In chapter 4 design of new Low Molecular Weight Gelators is presented. Aspects such as the relationships between molecular structure, crystal packing and gelation properties and the application of this kind of gels as a medium for crystal growth of organic molecules, such as APIs, are also discussed.

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41

D’Agostino, Simone <1981&gt. "Preparation of new crystal forms via photochemical, mechanochemical and sol-gel methods". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amsdottorato.unibo.it/4650/.

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This work of thesis involves various aspects of crystal engineering. Chapter 1 focuses on crystals containing crown ether complexes. Aspects such as the possibility of preparing these materials by non-solution methods, i.e. by direct reaction of the solid components, thermal behavior and also isomorphism and interconversion between hydrates are taken into account. In chapter 2 a study is presented aimed to understanding the relationship between hydrogen bonding capability and shape of the building blocks chosen to construct crystals. The focus is on the control exerted by shape on the organization of sandwich cations such as cobalticinium, decamethylcobalticinium and bisbenzenchromium(I) and on the aggregation of monoanions all containing carboxylic and carboxylate groups, into 0-D, 1-D, 2-D and 3-D networks. Reactions conducted in multi-component molecular assemblies or co-crystals have been recognized as a way to control reactivity in the solid state. The [2+2] photodimerization of olefins is a successful demonstration of how templated solid state synthesis can efficiently synthesize unique materials with remarkable stereoselectivity and under environment-friendly conditions. A demonstration of this synthetic strategy is given in chapter 3. The combination of various types of intermolecular linkages, leading to formation of high order aggregation and crystalline materials or to a random aggregation resulting in an amorphous precipitate, may not go to completeness. In such rare cases an aggregation process intermediate between crystalline and amorphous materials is observed, resulting in the formation of a gel, i.e. a viscoelastic solid-like or liquid-like material. In chapter 4 design of new Low Molecular Weight Gelators is presented. Aspects such as the relationships between molecular structure, crystal packing and gelation properties and the application of this kind of gels as a medium for crystal growth of organic molecules, such as APIs, are also discussed.

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42

Godard, Antoine. "Etude numérique et expérimentale d'un compresseur aspiré". Phd thesis, Ecole Centrale de Lyon, 2010. http://tel.archives-ouvertes.fr/tel-00728814.

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Afin d'alléger les moteurs d'avions et diminuer la consommation de carburant, les industriels tendent à rendre plus compact le système de compression de leurs moteurs, qui représente environ 40% de la masse totale. Or, à taux de compression global égal, la réduction du nombre d'étages implique une charge aérodynamique plus élevée par étage. Cela augmente d'autant les risques de décollements sur les aubes et la dégradation des performances. L'aspiration de la couche limite sur les aubages s'est révélée très prometteuse pour supprimer ces décollements néfastes et satisfaire aux besoins de charge aérodynamique élevée. Cependant, l'aspiration modifie fortement la distribution de pression statique à la paroi des aubes, rendant les approches de conception traditionnelles inadaptées. L'objectif de ce travail de thèse est donc de proposer une nouvelle méthode et de nouveaux critères de conception d'aubages fortement chargés, intégrant l'aspiration de la couche limite. Cette méthode repose sur une stratégie d'aspiration en deux étapes. Dans un premier temps, un contrôle passif, par courbure et diffusion, de la position du point de décollement est effectué dans le but de la rendre insensible aux conditions de fonctionnement. Dans un second temps, un contrôle actif par aspiration vise à placer la fente d'aspiration par rapport au point de décollement de manière à minimiser le taux d'aspiration nécessaire au recollement de la couche limite. Afin de mettre en pratique cette stratégie, une technique de dessin d'aubages par prescription de la distribution de courbure de l'extrados et de la variation de section du canal inter-aubes, est ainsi développée. Associée à un outil de pré-dimensionnement rapide ainsi qu'une évaluation des pertes de pression totale incluant la présence d'aspiration, cette méthode permet ainsi de concevoir une grille de stator aspirée subsonique réalisant une déflexion fluide de 60 degrés, pour un nombre de Mach amont de 0,5, correspondant à un facteur de diffusion de 0,73. Cette performance au point nominal est obtenue avec un coefficient de pertes de pression totale de 2,5%, en aspirant 1,1% du débit entrant dans la grille. Ces valeurs peuvent néanmoins être réduites respectivement à 2,1% et 0,8% par l'emploi d'une fente d'aspiration à bords arrondis. Cette étude numérique bidimensionnelle est effectuée à l'aide du code de calcul elsA de l'ONERA. Afin de valider expérimentalement cette méthode de conception ainsi que les outils numériques associés, une grille d'aubes plane est construite et testée à basse vitesse au laboratoire de Mécanique de Fluides et d'Acoustique de l'Ecole Centrale de Lyon. A mi-envergure, les résultats issus de l'expérience et de simulations numériques 3D confirment la pertinence de la stratégie d'aspiration et la démarche de conception adoptée. Cette confrontation met alors en évidence l'impact de la distribution du taux d'aspiration suivant l'envergure sur l'efficacité de l'aspiration. Etant donné l'importance des écoulements tridimensionnels rencontrés, une généralisation en trois dimensions de la stratégie d'aspiration est proposée et est appliquée numériquement sur cette même grille d'aubes. En contrôlant simultanément les couches limites se développant sur l'aube et sur les parois latérales du canal de compression, il est alors possible de supprimer presque totalement les décollements de coins présents dans celui-ci. En contrepartie, le taux d'aspiration voit sa valeur augmenter très fortement, tempérant ce bénéfice. L'épaisseur des couches limites entrantes se révèle alors également être un facteur déterminant pour le succès du contrôle des couches limites par aspiration, dans un cadre tridimensionnel.

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43

DI, DONATO FRANCESCA. "Traceability and Authenticity of high-valued dairy products by combining Analytical and Chemometric methods". Doctoral thesis, Università degli Studi dell'Aquila, 2022. http://hdl.handle.net/11697/192077.

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An extended and updated list of analytical techniques for confirmation of food authentication and to support law enforcement is nowadays strongly demanded by food safety and quality control organizations all over the world, presiding over the farm to fork continuum of each specific sector of food. Analytical Chemistry can give a decisive answer in this direction playing an active role in restoring dignity to traditional food species, due to the potentiality of many available techniques to provide traceability and authenticity information. The scientific community is indeed offering proven, accurate and reliable methods to protect and clearly distinguish high-valued food products from any illegal substitutes setting-up applications as fast, efficient, cheap, and easily applicable (at custom level) as possible. Into an era of high-throughput analytical devices, Chemometrics, giving the necessary multivariate statistical-mathematical and computing expertise, is co-evolving fast together with Analytical Chemistry. From the food-traceability and authentication point of view, in particular, Chemometrics grants the need to extract only relevant information and obtain reliable models capable of inferring the underlying relationships which link the complex compositional profile of food products and processing conditions to very general end-properties of foodstuffs, such as healthiness, consumer perception, or to a specific territory. Authenticity and traceability, then, are inherently multivariate, covering many different aspects: chemical and physical characterization, adulteration, discrimination, mislabeling, and monitoring of the production process. Under these perspectives, the research studies the present PhD thesis lays on involve the development of new analytical methods reinforced by Chemometrics to handle different food traceability and authentication cases. The bulls-eye has been focused on the dairy sector, characterized by several decades of increased market disturbance. A number of intervention mechanisms have been indeed put in place to promote and protect the milk sector and give it back value. Nowadays, milk sector represents a significant proportion of the value of European Union-agricultural output. Total EU milk production is estimated to be second only to India; moreover, EU is a major exporter of dairy products and the biggest one in the world for cheese. More in details, the reader will be led through different applications handling several food-related issues, focusing on dairy products: from the authentication of cheeses labeled with quality schemes, to the contamination of niche products with cheaper one, and the monitoring of storage conditions. Both targeted analysis, giving information about singular molecular and atomic species, and fingerprinting techniques, providing convoluted profiles of foodstuffs, have been employed and compared in performances in this thesis. Exploratory multivariate analysis and different single- and multi-block supervised pattern recognition methods have been employed to interpret the instrumental outputs. The excellent results obtained in the reported applications support the effective and indispensable role of chemometric processing in the field of food control to handle such complex matrices, like dairy products are. For my own part I hope to have made a good service to the scientific community, providing another brick in the wall in such greatly discussed and of real-time-interest field of knowledge.

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44

LAMMI, Carmen. "Innovative Functional Methods Useful for New Cellular Target Identification and for Receptor Ligand Characterization". Doctoral thesis, Università degli Studi di Camerino, 2011. http://hdl.handle.net/11581/401858.

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G-protein coupled receptors (GPCRs) are a large family of receptor proteins that play important roles in many physiological and pathological conditions. In drug discovery, they are one of the most important drug targets. In particular, adenosine receptors, classified as A1, A2A, A2B and A3 (A1AR, A2AAR, A2BAR, and A3AR) subtypes, have been actively studied as potential therapeutic targets in several disorders such as cardiovascular and CNS pathologies. The aim of the present work is the development of innovative and non-radioactive screening systems in order to study a large number of adenosine P1 receptor ligands. On the other hand, since new assays could be useful to contribute to receptor deorphanization, the task work has been focused to characterize the putative guanosine receptor and the novel dual uracil nucleotide/cysteinyl-leukotriene receptor, GPR17. In particular, functional cAMP and DELFIA GTP-Eu binding assays were used. The cAMP immuno-competitive assay, performed in homogeneous time resolved fluorescence (HTRF), was optimized and validated using as reference agonists NECA at A2AAR and A2BAR, and Cl-IBMECA at A3AR. Hence, after this assay validation, the biological profile of a series of 8-substituted 9-ethyladenines was assessed at A2AAR. Results showed that all compounds behave as A2AAR antagonists. On the other hand, an innovative luminescence cAMP assay, that uses a genetically modified form of firefly luciferase containing a cAMP-binding protein moiety, was developed for ARs. Two new improved plasmids containing the gene for the modified form of firefly luciferase were optimized and validated at ARs in order to verify their efficacy at GÎ±s and GÎ±i systems. In particular, the experiments were carried out by transiently expressing these new vectors at CHO cell line stably transfected with A2A and A3 ARs. Results showed that both plasmids can be used at ARs and since this assay demonstrated to be robust and reproducible, it was used as new tool to investigate the novel ''dual'' GPR17. Furthermore, the better evaluation of the ''dual'' nature of the human GPR17 could be carried out in 1321N1 cells since they do not constitutively express nucleotide and cysteinyl-leukotriene receptors. In particular, different transient transfection methods such as calcium phosphate, lipofectamine, fugene, arrest-InTM and microporation, have been investigated. Experiments were performed using also in parallel GFP as reporter gene and results analyzed by RT-PCR suggested that microporator as well as Arrest-In are both the best method to promote an enriched hgpr17 delivery into 1321N1 cell line. Moreover, DELFIA GTP-Eu binding assay was carried out using CHO-A3 membranes. The standardization of DELFIA GTP-Eu assay is a long process, in which the determination of the specific receptor buffer stimulation was the first crucial step investigated. The assay validation was carried out using know ligands and subsequently, a new series of 2-alkynyl-N6-methyl-5'-N-methylcarboxamidoAdo derivatives were screened and results suggested that they are full agonists at A3AR. Subsequently, the assay potentialities were extended at native tissue. In particular, rat brain membranes were prepared from Male Wistar rat and used to investigate putative guanosine receptor by testing known and novel ligands. Results obtained suggested the presence of a G-protein coupled receptor able to be activated by guanosine and some guanosine derivatives. The AGC is a family of kinase that is composed of 60 different enzymes including PKC isoforms, PKB/AKT, S6K and their upstream kinase, the phosphoinositide-dependent protein kinase 1 (PDK1). In particular, located in the small loop of the kinase domain is present a pocket called PIF-binding pocket that is involved in the regulation of the intrinsic activity of these kinases. The molecular mechanism of allosteric activation of PDK1 by small molecular weight prodrugs and their effects in C2C12 cells were evaluated. In particular experiments were carried out incubating C2C12 with PS423 and PS0403, small chemical entities synthesized by the PhosphoSites research group, and after cell insulin stimulation the PDK1 pathway was investigated. Results obtained suggested that these compounds were able to bind the PIF-binding pocket inhibiting the S6K phosphorylation without affecting the PKB activity. On the other hand, the in cell western was optimized at C2C12, as new assay to screen and to evaluate in a throughput way the effects of several PS-compounds on the S6K phosphorylation by PDK1. Results demonstrated that the in cell western is a robust, reproducible and easy to use assay to screen directly in the cell several compounds in the same experiments.

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45

Maffucci, I. "OPTIMIZATION AND APPLICATION OF COMPUTATIONAL METHODS FOR THE DESIGN OF PROTEIN-PROTEIN INTERACTIONS MODULATORS". Doctoral thesis, Università degli Studi di Milano, 2015. http://hdl.handle.net/2434/344181.

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In the wide field of PPIs, this PhD project has been focused on the optimization and application of computational methods for the design of PPIs modulators, with a particular interest toward peptide modulators targeting PPIs involving helical motifs. In this contest, the first part of the project has been aimed to define the rationales behind the helical secondary structure stabilization and the helical screw sense selectivity exerted by chiral Cα-tetrasubstituted amino acids (cCTAAs) through REMD simulations and QTAIM analyses, and the mechanisms responsible of the helical screw sense inversion through PNEB simulations. In detail, it has been found that the helical motif is stabilized by two complementary mechanisms: the first depends on the steric hindrance exerted by the cCTAA in an area parallel to the peptide helix axis and downstream of the cCTAA itself, whereas the second consists in the strengthening of the helical H-bond network thanks to peculiar C-H···O=C interactions. Analogously, P-helical screw sense selectivity is ascribable to the cCTAA steric hindrance parallel to the peptide helix axis, without particular preferences for the region downstream and upstream of the cCTAA, together with quite strong noncovalent interactions, consisting of classical N – H···O=C H-bonds and weak C – H···O=C interactions. Furthermore, PNEB simulations performed on achiral peptides of different lengths suggest that the helical screw sense inversion requires the formation of γ-turns, although a preferential screw sense inversion direction was not found. Therefore, the knowledge gained from these studies could be helpful in designing stable helical peptides, having a preferential screw sense and that can be in principle activated in situ by inducing a conformational switch from P to M helix or vice versa. Conversely, the second part of the project has been focused on the optimization of an MMGBSA based method, called Nwat-MMGBSA, aimed to improve the correlation between predicted binding energies of PPI complexes and experimental data. This approach, consisting in the inclusion, as part of the receptor, of hydration shells around the ligand during the MMGBSA calculations, was initially tested on classical receptor-ligand complexes and, then, automatized, optimized and tested on PPI complexes. This approach turned out to be good for the evaluation of PPI modulators activities, from different points of view. First of all, when water played a significant role in mediating protein-ligand interactions, the application of Nwat-MMGBSA improved the correlation between predicted and experimental data. On the other hand, if the solvent does not explicitly participate to the interaction, it did not give detrimental results compared to those obtained with the standard approach. In addition, the protocol proved to be robust and reproducible, giving equivalent results by using different setups. Furthermore, although an optimal number of water molecules to include in the hydration shell could not be found, in the case of PPI interactions inhibited by small molecules the inclusion of 50 – 60 water molecules appears to be a good choice. A non-negligible advantage of this approach is represented by the possibility to automatize it, making it applicable for drug design/discovery purposes. Therefore, although further evaluations are needed, most of all on larger datasets, the knowledge coming from the combination of both parts of the project can be exploited for the design of stable non-natural peptides targeting PPIs.

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46

Satta, Alessio <1971&gt. "An index-based method to assess vulnerabilities and risks of Mediterranean coastal zones to multiple hazards". Doctoral thesis, Università Ca' Foscari Venezia, 2014. http://hdl.handle.net/10579/5594.

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Il presente lavoro di tesi ha sviluppato un indice per la valutazione integrata del rischio costiero generato da molteplici pericolosità con l'obiettivo di supportare le autorità costiere del Mediterraneo nel pianificare l'adattamento ai cambiamenti climatici. Con riferimento al quadro teorico definito da IPCC nel "Fifth Assessment Report" è stata costruita una funzione di rischio al fine di trasformare le definizioni teoriche in un metodo concreto di valutazione. Il rischio è stato definito come il risultato dell'azione congiunta delle forzanti climatiche e non climatiche sulle pericolosità naturali agenti sul sistema costiero, quest'ultimo caratterizzato dai fattori di vulnerabilità e di esposizione. Con riferimento al protocollo GIZC, questo lavoro di tesi propone una metodologia per definire le zone costiere di pericolosità (ZCP) per le singole pericolosità e per l'azione congiunta di molteplici pericolosità. In tal senso è stato sviluppato un indice di rischio per le tre pericolosità costiere (erosione, inondazione marina e intrusione salina) e per molteplici pericolosità (MHCRI). L'indice MHCRI è stato applicato a un caso concreto nella costa occidentale della Sardegna (Italia). I risultati includono le mappe di vulnerabilità e di rischio per ogni singola pericolosità e per molteplici pericolosità.

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47

Aieta, C. D. "QUANTUM AND SEMICLASSICAL METHODS FOR RATE CONSTANT CALCULATIONS". Doctoral thesis, Università degli Studi di Milano, 2018. http://hdl.handle.net/2434/546203.

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Chemical reactions are intrinsically dynamical processes. Reaction rate constants, and thus the understanding of chemical kinetics, can be in principle obtained at a very detailed level if one is able to compute the real time quantum dynamics for the reactive system. Unfortunately, the numerical implementation of real time quantum dynamics is very hard to perform, especially for high dimensional systems, because the computational effort scales exponentially with the number of degrees of freedom. In this Ph.D. thesis, two open problems in reaction rate theory have been addressed. The first one is to extend to high dimensional systems the inclusion of quantum effects in rate constant computations. The second issue deal with the inclusion of real time dynamics into very accurate rate constants calculations. The thesis is organized as follows. After a general Introduction, the second chapter is an overview of the state of the art in reaction rate theory. Then, in the third chapter, the derivation of Miller's Semiclassical Transition State Theory (SCTST) is recalled. SCTST is the method employed to obtain accurate and quantum-corrected rate constants for high dimensional reactions. In chapter 4, a novel parallel implementation of this theory (that has also been released as an open source code into J. R. Barker's MultiWell suite of codes) is described together with its application to high dimensional systems. In the following chapters, a new quantum rate approach able to include real time dynamics effects is presented. Derivation and applications of the latter are thoroughly described in chapter 6. The thesis ends with some perspectives about possible future developments.

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48

LAVARELLO, CHIARA. "Innovative analytical methods for the study of low and high weight molecules involved in diseases". Doctoral thesis, Università degli studi di Genova, 2021. http://hdl.handle.net/11567/1040103.

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Personalized or precision medicine is an emerging approach to the treatment and prevention of disease, which takes into account the individual variability of genes, environment and lifestyles of each person. High Resolution Mass Spectrometry (HRMS) coupled with Ultra High Performance Liquid Chromatography (UHPLC) plays a fundamental role in characterizing and quantifying proteins and metabolites involved in the disease. The proteomic and metabolomic approaches allow the global identification, not guided by a priori hypothesis, of thousands of proteins and hundreds of metabolites present in a biological fluid and the evaluation of how these can vary in the presence of a specific disease compared to a non-pathological condition, allowing to characterize and discriminate between different study groups. In the first part PhD project has been studied the proteomic profile of autoinflammatory diseases to understand the molecular mechanisms underlying genetic diseases. Here, we analyzed the proteomic signature of unstimulated and stimulated monocytes of patients with FMF, TRAPS and MKD, describing the dysregulated intracellular pathways associated with each condition for the identification of possible biomarkers and possible novel therapeutic targets. The objective of the second part of the project is to build, optimize and share spectral MSMS with Accurate Mass Retention Time (AMRT) database libraries, using different metabolic standards (MSMLS, IROA Technologies), involved in key biological processes, to develop robust identification and quantitative methods because the compound identification process being often challenging and requiring a high degree of confidence.

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49

Conti, Roberto <1986&gt. "Analytical Pyrolysis and Microextraction Methods to Characterize Oil and Biochar from Thermal and Catalytic Cracking of Biomass". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amsdottorato.unibo.it/7320/1/Conti_Roberto_Tesi.pdf.

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In this dissertation thermal and catalytic pyrolysis of protein-rich biomass was investigated. The study was focused on the liquid and solid products. This thesis was aimed to gather chemical information on the thermal behavior of proteinaceous substrates in the presence of zeolite and compare with lignocellulosic biomass. Furthermore, the thesis was focused on the development of reliable analytical methods by means of Py-GC-MS in order to predicting bio-oil composition and to investigating biochar structure and its correlation with thermal stability. In addition a sampling procedure for the direct analysis of pyrolysis vapours based on absorption onto a microfiber (SPME) was developed. Py-GC-MS was applied as screening method to study the effect of different catalysts (H-ZSM5, MCM-41) and biomass-catalyst weight ratio on aromatic hydrocarbons production. The obtained results demonstrated that Py-GC-MS enable the selection of pyrolysis conditions. H-ZSM5 confirmed to be the catalyst with the best performance in terms of hydrocarbon production. In addition, the chemical composition observed by Py-GC-MS significantly reflects that obtained on bench scale. However, some difference has been found. Indeed, formation of high molecular weight PAHs have been observed only on bench scale and nitrogen-containing compounds and oxygenated compounds exhibited some difference related to condensation step. Problems during condensation step led to using SPME as at-line monitoring technique during the process capable of hot gas phase analysis. Strong similarity between GC-MS analysis of hot vapours and bio-oil from condensation traps were found. Finally, Py-GC-MS was applied to the chemical characterization of biochars obtained under different pyrolysis conditions or from different feedstock. Py-GC-MS can provide molecular indices useful to gather information on biochar thermal stability and to predicting the biochar carbonization degree. Furthermore, the molecular pattern resulting from Py-GC-MS could be utilized to infer information on the nature of the initial substrate and differentiate biochars.

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50

Conti, Roberto <1986&gt. "Analytical Pyrolysis and Microextraction Methods to Characterize Oil and Biochar from Thermal and Catalytic Cracking of Biomass". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amsdottorato.unibo.it/7320/.

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In this dissertation thermal and catalytic pyrolysis of protein-rich biomass was investigated. The study was focused on the liquid and solid products. This thesis was aimed to gather chemical information on the thermal behavior of proteinaceous substrates in the presence of zeolite and compare with lignocellulosic biomass. Furthermore, the thesis was focused on the development of reliable analytical methods by means of Py-GC-MS in order to predicting bio-oil composition and to investigating biochar structure and its correlation with thermal stability. In addition a sampling procedure for the direct analysis of pyrolysis vapours based on absorption onto a microfiber (SPME) was developed. Py-GC-MS was applied as screening method to study the effect of different catalysts (H-ZSM5, MCM-41) and biomass-catalyst weight ratio on aromatic hydrocarbons production. The obtained results demonstrated that Py-GC-MS enable the selection of pyrolysis conditions. H-ZSM5 confirmed to be the catalyst with the best performance in terms of hydrocarbon production. In addition, the chemical composition observed by Py-GC-MS significantly reflects that obtained on bench scale. However, some difference has been found. Indeed, formation of high molecular weight PAHs have been observed only on bench scale and nitrogen-containing compounds and oxygenated compounds exhibited some difference related to condensation step. Problems during condensation step led to using SPME as at-line monitoring technique during the process capable of hot gas phase analysis. Strong similarity between GC-MS analysis of hot vapours and bio-oil from condensation traps were found. Finally, Py-GC-MS was applied to the chemical characterization of biochars obtained under different pyrolysis conditions or from different feedstock. Py-GC-MS can provide molecular indices useful to gather information on biochar thermal stability and to predicting the biochar carbonization degree. Furthermore, the molecular pattern resulting from Py-GC-MS could be utilized to infer information on the nature of the initial substrate and differentiate biochars.

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