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Applications of Mass Spectrometry in Proteomics and Pharmacokinetics
No full textTremendous technology improvements of the last decades has given mass
spectrometry a more and more expanding role in the study of a wide range of
molecules: from the identification and quantification of small molecular weight
molecules to the structural determination of biomacromolecules. Many are the
fields of application for this technique and the various versions of it.
In the present study three different applications have been explored.
The first application is a pharmacokinetics study of anticancer drug Gemcitabine
and its principal metabolite, where the role of the LC-MS/MS is essential both for
the selectivity of the detection of the small analytes and the sensitivity enhanced
by multi-reaction monitoring experiments. The design of the study involved the
collection of several blood samples at selected times and from patients that
would have met certain eligibility criteria. The ESI demonstrated to be the most
suitable approach and it provided the necessary data to conclude that toxicity of
Gemcitabine did not increase when administered at FDR (Fixed Dose Rate)
infusion in patients with impaired hepatic function.
The second application describes an example of how MS represents a powerful
tool in cancer research, from serum profiling study with high resolution MALDITOF
and bioinformatic analysis, to the identification of potential biomarker
through peak identification. Almost 400 serum sample – homogeneously
distributed between biopsy confirmed ovarian cancer and high risk serum
samples – were analyzed on a high resolution MALDI-TOF instrument after
automated reverse phase magnetic beads separation. The high throughput data
have undergone sophisticated bioinformatic procedures that lead to a list of upand
down-regulated peaks, although identification studies were possible only for
those peaks that showed a good reproducibility. One down-regolated peak has
been identified using the LC-MS/MS technique. The identified peak confirmed a
basic role of fibrinogen in the ovarian cancer; the other four peaks that have been identified as down-regulated showed an absolutely not satisfactory ionization in
electro-spray, therefore further analysis will be performed on these analytes in
order to determinate their amino acidic sequence. The most suitable technique
seems to be MALDI-TOF/TOF mass spectrometry, since the peptides already
showed a good degree of ionization in MALDI.
The third and last study belongs to a quite new field, which is the combination of
immuno precipitation assays with MALDI-TOF (Immuno Precipitation Mass
Spectrometry, IPMS) experiments in order to evaluate the specificity of a series
of monoclonal antibodies to specific antigen. The automated assay that has been
developed provides structural information about the antigen that binds the
monoclonal antibody to be tested and previously conjugated to the surface of
magnetic beads, ideal support for robotic automation. IPMS showed its potential
as a complementary tool of crucial importance in the selection of the monoclonal
antibody for the development of ELISA based assay to be applied in the
screening of a consistent number of human specimens for the clinical validation
of proteins indicated in literature as potential biomarkers.
Mass spectrometry in association with fractionation techniques, such as liquid or
magnetic beads chromatography, is a very flexible tool in the cancer research
field. Further improvement in the instrumentation and in the technology will bring
always more and more results to be confident in.Thesis submitted
for the degree of Philosophiæ Doctor
Faculty of Pharmacy
Sapienza Università di Roma, Italy
200
Visual Estimation and Control of Robot Manipulating Systems
No full textWith this sentence from his Metaphysica, Aristotle perfectly introduces us to the
importance of eyesight for humans, as well as for any advanced living being. Since, to
a large extent, robotics is concerned with the emulation of human skills in an artificial
context, a natural requirement is to cope with vision for a full interaction with the world. In this
respect, this Thesis explores the problem of exploiting visual information to control the motion
of robotic systems equipped with onboard cameras. We build our proposals upon the Visual
Servoing paradigm, which bridges Computer Vision (image processing, scene interpretation,
feature extraction, etc.) with topics proper to the Control Theory field. Indeed, within Visual
Servoing, a camera is modeled as a nonlinear function of the scene, i.e., of 3D states subject to
rigid body kinematics. Therefore, visual pose control reduces to a problem of output regulation,
or task realization if we conform to the robotic nomenclature. Once this view is adopted, any
task realization algorithm can be used to fulfill a visual task, and, more in general, the problem
can be tackled with the tools of Control Theory.
In order to fully exploit this formulation, however, a suitable task-oriented modeling of robot
manipulators is required. Therefore, in the first part of the Thesis, we develop a theoretical
framework for kinematic modeling and control of such systems. While keeping the treatment at
the most general level, we place some emphasis on the cases of fixed and nonholonomic mobile
manipulators. Indeed, the former class is ubiquitous in robotics, and the latter conveniently
merges dexterity with extended ( unlimited) workspace capabilities. A special attention is
also devoted to the exploitation of possible redundancy with respect to a given task, in terms
of both improvement of overall performance, and satisfaction of secondary constraints.
Such modeling framework is then combined with the schemes proper to Visual Servoing
to obtain a unique formulation for visual task control. Again, the two cases of fixed-base
and nonholonomic mobile manipulators are explicitly considered, and any inherent peculiarity
is pointed out. We also show how a suitable use of redundancy can effectively improve the
fulfillment of Visual Servoing tasks. For instance, it can allow realization of tasks that would
be close to singularity when addressed altogether. Another contribution to this topic is the
possibility to estimate online several unmeasurable 3D quantities that are lost through the
projective mapping performed by a camera. To this end, a set of estimation tools based on the
nonlinear observation theory is proposed, so as to recover at runtime any 3D information needed
by Visual Servoing schemes. With respect to other possible approximations, this solution takes
advantage of the observation convergence in order to improve the overall closed-loop stability.
Finally, the theoretical claims and simulation results presented in the Thesis are further
validated by a number of experiments run on real robots equipped with cameras. The proposed
methodology is also exploited within an industrial application involving pick-and-assemble
tasks. A fixed-base manipulator carrying a camera on the gripper must (i) autonomously
locate a set of planar parts on a table, (ii) pick them up, (iii) locate the corresponding
holes on a movable plate, and (iv) insert the parts. Robot motion during the approaching
phases to parts/holes is governed by Visual Servoing techniques, so as to obtain the needed
degree of robustness and reactivity with respect to external ‘disturbances’, such as unexpected
displacements of the target items
SUPERCONDUCTIVITY IN STRONGLY CORRELATED ELECTRON SYSTEMS: ANALYTICAL APPROACHES BEYOND DYNAMICAL MEAN FIELD THEORY
No full textThe present thesis presents a systematic study of the possible cluster extensions of the dynamical mean field theory (DMFT). In particular, the role of the cluster geometry is investigated analytically in the relevant case of two-dimensional lattices with d-wave superconducting order
The ruled surfaces and the developable surfaces: a re-reading through the virtual laboratory
No full textThe objective of this study is to reveal the properties of ruled surfaces and developable surfaces through Virtual laboratory and, overall, to be a contribution to the renewal of descriptive geometry. The basis of the research lies within the scientic foundations of drawing and of mathematical representation method. The study’s structure can be divided into two essential moments: - the historical recognition on ruled surfaces from the point of view of solid geometry and descriptive and projective geometry, going from the treaty of J.N. P. Hachette (1828) to the texts of G. Fiedler (1878), F. Aschieri (1888) and G. Fano (1925); - the rereading of theoretical propositions concerning this two type of surfaces, through a series of experiments carried out within the virtual laboratory of new descriptive geometry. A virtual laboratory can be de_ ned as a digital workshop, where it is possible to control directly in a three-dimensional space the problems of shapes’ generation that may be found in geometry and architecture. As a matter of fact, computer, besides its limits in modeling, has proved to be an essential tool for the display of some properties of ruled surfaces. Several theoretical concepts I have analyzed are only enunciated in literature, but were never represented. The reason is the complexity of these drawings that could only be realized with the rule and compasses at that time. I am referring to some properties explained by J. N. P. Hachette and G. Fano, but not only these. Hachette was a mathematician, as was Monge before him. Most of his thoughts on ruled surfaces are the result of analytical studies or geometrical intuitions; as a consequence, when the representation becomes too complex it is left to the readers’ imagination. In conclusion, the objective of this research is also to reveal through representation what was only enunciated with words on theoretical basis. In this respect, I believe that the greatest contribution of informatics revolution to the study of descriptive geometry is the consolidation of drawing as an instrument of the logic, in other words as a tool for discovery and verication of geometrical thoughts
Idrocarburi clorurati volatili in aria Determinazione del rapporto di concentrazione atmosfera/ambiente acquatico
No full textOgni anno centinaia di migliaia di tonnellate di idrocarburi clorurati volatili (VCHC) sono immesse in atmosfera, a causa del largo impiego che tali composti trovano in vari processi industriali e commerciali. Grazie alle loro proprietà chimico-fisiche (in particolare volatilità e persistenza) e al loro tempo di vita medio moderatamente lungo, i VCHC si diffondono dalle aree industrializzate e raggiungono le zone più remote della Terra come il continente antartico. Questa diffusione su larga scala avviene attraverso un trasporto a lungo raggio veicolato dall'atmosfera e dalle correnti oceaniche, in particolare attraverso un processo noto come ciclo di distillazione e frazionamento globale. Alla luce della riscontrata tossicità e ubiquità dei VCHC appare evidente l’importanza di un monitoraggio continuato in atmosfera e in ambiente acquatico e di uno studio puntuale della distribuzione di queste sostanze tra i compartimenti ambientali. Informazioni rilevanti soprattutto quando si riferiscono alla presenza e al comportamento dei VCHC in zone remote e caratterizzate da particolari condizioni ambientali come l’Antartide dove, a causa delle basse temperature, i contaminanti restano intrappolati e possono dar luogo a fenomeni di accumulo.
In questo lavoro di dottorato è stata pertanto realizzata e ottimizzata una linea analitica per la determinazione dei VCHC in aria a livello pptV (10-12 L/L) basata sull'accoppiamento di un cryofocusing trap injector con un gascromatografo a sua volta interfacciato con uno spettrometro di massa operante in modalità SIM (CTI-GC-MS). Inoltre è stato messo a punto un metodo di campionamento di aria adatto a determinazioni a livello di tracce e compatibile con le condizioni climatiche antartiche.
Con tali metodi sono stati prelevati e analizzati campioni di aria di differente origine, sia italiani che antartici; i VCHC sono stati rinvenuti in tutti i campioni con concentrazioni che variano da unità a centinaia di pptV. Impiegando poi anche la tecnica adatta all'analisi dei VCHC nelle matrici acquose sono stati analizzati campioni di aria, acqua e neve prelevati contemporaneamente allo scopo di determinare oltre alla composizione, il rapporto di concentrazione atmosfera/ambiente acquatico dei VCHC. È stato inoltre studiato come tale rapporto cambi passando da una zona temperata e industrializzata come l’Italia a una zona polare e remota come l’Antartide. In tal senso tale lavoro ha lo scopo di portare un notevole contributo alla comprensione del comportamento ambientale dei composti in studio, dei loro meccanismi di trasporto e distribuzione tra atmosfera e ambiente acquatico. Tra l’altro attualmente non esiste uno studio specifico sul comportamento dei VCHC relativamente alle caratteristiche climatiche antartiche, di conseguenza tali dati potrebbero essere un utile supporto all'elaborazione teorica dei modelli di distribuzione e destino ambientale.PNRA Progetto Nazionale di Ricerche in Antartid
MESSA A PUNTO, VALIDAZIONE E VALUTAZIONE SU CAMPO DI INNOVATIVI SISTEMI DI CAMPIONAMENTO
No full textCOMPORTAMENTO DI GRANDI FRANE IN ARGILLE
No full textFrancesco Silvestri, Federica Cotecchia, Cristina Jomm
Modeling of Ablation Phenomena in Space Applications
No full textGuido Colasurdo, Maria Vittoria Salvetti, Walter d'Ambrogi
Gcn5p plays an important role in centromere-kinetochore function in budding yeast
No full textMarco Tripodi, Paolo Ascenzi, Federico da Settimo, David Modian