A phase I randomized, double-blind, controlled trial of 2009 influenza A (H1N1) inactivated monovalent vaccines with different adjuvant systems

Methods We conducted a phase I, multicenter, randomized, double-blind, placebo-controlled, multi-arm (10) parallel study involving healthy adults to evaluate the safety and immunogenicity of influenza A (H1N1) 2009 non-adjuvanted and adjuvanted candidate vaccines. Subjects received two intramuscular injections of one of the candidate vaccines administered 21 days apart. Antibody responses were measured by means of hemagglutination-inhibition assay before and 21 days after each vaccination. The three co-primary immunogenicity end points were the proportion of seroprotection >70%, seroconversion >40%, and the factor increase in the geometric mean titer >2.5. Results A total of 266 participants were enrolled into the study. No deaths or serious adverse events were reported. The most commonly solicited local and systemic adverse events were injection-site pain and headache, respectively. Only three subjects (1.1%) reported severe injection-site pain. Four 2009 influenza A (H1N1) inactivated monovalent candidate vaccines that met the three requirements to evaluate influenza protection, after a single dose, were identified: 15 μg of hemagglutinin antigen without adjuvant; 7.5 μg of hemagglutinin antigen with aluminum hydroxide, MPL and squalene; 3.75 μg of hemagglutinin antigen with aluminum hydroxide and MPL; and 3.75 μg of hemagglutinin antigen with aluminum hydroxide and squalene. Conclusions Adjuvant systems can be safely used in influenza vaccines, including the adjuvant monophosphoryl lipid A (MPL) derived from Bordetella pertussis with squalene and aluminum hydroxide, MPL with aluminum hydroxide, and squalene and aluminum hydroxide.

Experimental Investigation of Three-Dimensional Single and Double optical Lattices

A complete laser cooling setup was built, with focus on threedimensional near-resonant optical lattices for cesium. These consist of regularly ordered micropotentials, created by the interference of four laser beams. One key feature of optical lattices is an inherent ”Sisyphus cooling” process. It efficiently extracts kinetic energy from the atoms, leading to equilibrium temperatures of a few µK. The corresponding kinetic energy is lower than the depth of the potential wells, so that atoms can be trapped. We performed detailed studies of the cooling processes in optical lattices by using the time-of-flight and absorption-imaging techniques. We investigated the dependence of the equilibrium temperature on the optical lattice parameters, such as detuning, optical potential and lattice geometry. The presence of neighbouring transitions in the cesium hyperfine level structure was used to break symmetries in order to identify, which role “red” and “blue” transitions play in the cooling. We also examined the limits for the cooling process in optical lattices, and the possible difference in steady-state velocity distributions for different directions. Moreover, in collaboration with ´Ecole Normale Sup´erieure in Paris, numerical simulations were performed in order to get more insight in the cooling dynamics of optical lattices. Optical lattices can keep atoms almost perfectly isolated from the environment and have therefore been suggested as a platform for a host of possible experiments aimed at coherent quantum manipulations, such as spin-squeezing and the implementation of quantum logic-gates. We developed a novel way to trap two different cesium ground states in two distinct, interpenetrating optical lattices, and to change the distance between sites of one lattice relative to sites of the other lattice. This is a first step towards the implementation of quantum simulation schemes in optical lattices.

Studio Sperimentale e Modellazione della Separazione di Proteine con Membrane di Affinità

Chromatography represents one of the most important and widely used unit operation in the biotechnology industry. However this technique suffers from several limitations such as high pressure drop, slow mass transfer through the diffusive pores and strong dependence of the binding capacity on flow rate. In this work, affinity membranes with improved capacity have been considered as an alternative technology for the capturing step in antibody manufacturing. Several affinity membranes have been prepared starting from various membrane supports. Different affinity ligands have been utilized like Protein A, the natural ligand of choice for antibodies, as well as synthetic ligands that exhibit affinity for the Fc portion of antibodies. The membranes have been characterized in detail: binding and elution performance was evaluated in adsorption experiments using pure IgG solutions, while membrane selectivity was evaluated using complex solutions like a cell culture supernatant. The most promising affinity membranes were extensively tested in dynamic experiments. The effects of operating parameters like feed concentration and flow rate on separation performances like binding capacity, selectivity and process yield have been studied in detail in order to find the optimal conditions for binding and elution steps. The membranes have been used over several complete chromatographic cycles to evaluate the effects of ageing and of membrane regeneration on dynamic binding capacity. A novel mathematical model is proposed that can describe all the chromatographic steps involved in the membrane affinity chromatography process for protein purification. The mathematical description is based on the species continuity equation coupled with a proper binding kinetic equation, and suitable to describe adequately the dispersion phenomena occurring both in the micro-porous membranes as well as in the extra-column devices used in the system. The model considers specifically all the different chromatographic steps, namely adsorption, washing and elution. The few relevant fitting parameters of the model were derived from a calibration with the experimental affinity cycles performed with pure IgG solutions, then the model is used to describe experimental data obtained in chromatographic cycles carried out with complex feeds as the cell culture supernatant. Simulations reveal a good agreement with experimental data in all the chromatography steps, both in the case of pure IgG solutions and for the cell culture supernatant considered.

Spin polarized transport in manganese oxide double-perovskite thin films

Gegenstand dieser Arbeit war die Untersuchung von metallischen gemischtvalenten Manganaten und magnetischen Doppelperowskiten. Aufgrund ihres großen negativen Magnetowiderstandes (MW) sind diese halbmetallischen Oxide interessant für mögliche technische Anwendungen, z.B. als Leseköpfe in Festplatten. Es wurden die kristallographischen, elektronischen und magnetischen Eigenschaften von epitaktischen Dünnschichten und polykristallinen Pulverproben bestimmt.Epitaktische Dünnschichten der Verbindungen La_0.67Ca_0.33MnO₃ und La_0.67Sr_0.33MnO₃ wurdenmit Kaltkathodenzerstäubung und Laserablation auf einkristallinen Substraten wie SrTiO₃abgeschieden. Mit Hall-Effekt Messungen wurde ein Zusammenbruch der Ladungsträgerdichte bei der Curie-Temperatur T_C beobachtet.Mit dem Wechsel des Dotierungsatoms A von Ca (T_C=232 K) zu Sr (T_C=345 K)in La_0.67A_0.33MnO₃ konnte die Feldsensitivität des Widerstandes bei Raumtemperatur gesteigert werden. Um die Sensitivität weiter zu erhöhen wurde die hohe Spinpolarisation von nahezu 100% in Tunnelexperimenten ausgenutzt. Dazu wurden biepitaktische La_0.67Ca_0.33MnO₃ Schichten auf SrTiO₃ Bikristallsubstraten hergestellt. Die Abhängigkeit des Tunnelmagnetowiderstandes (TMW) vom magnetischen Feld, Temperatur und Strum war ein Schwerpunkt der Untersuchung. Mittels spinpolarisierten Tunnelns durch die künstliche Korngrenze konnte ein hysteretischer TMW von 70% bei 4 K in kleinen Magnetfeldern von 120 Oe gemessen werden. Eine weitere magnetische Oxidverbindung, der Doppelperowskit Sr₂FeMoO₆ miteine Curie-Temperatur oberhalb 400 K und einem großen MW wurde mittels Laserablation hergestellt. Die Proben zeigten erstmals das Sättigunsmoment, welches von einer idealen ferrimagnetischen Anordnung der Fe und Mo Ionen erwartet wird. Mit Hilfe von Magnetotransportmessungen und Röntgendiffraktometrie konnte eine Abhängigkeit zwischen Kristallstruktur (Ordnung oder Unordnung im Fe, Mo Untergitter) und elektronischem Transport (metallisch oder halbleitend) aufgedeckt werden.Eine zweiter Doppelperowskit Ca₂FeReO₆ wurde im Detail als Pulverprobe untersucht. Diese Verbindung besitzt die höchste Curie-Temperatur von 540 K, die bis jetzt in magnetischen Perowskiten gefunden wurde. Mit Neutronenstreuung wurde eine verzerrte monoklinische Struktur und eine Phasenseparation aufgedeckt.

Double-stimulus sensitive (temperature and pH) self-assemblable polymers

The rheological properties of block co-polymers in water solution at different pH have been investigated. The block copolymers are based on different architectures containing poly(ethylene glycol), poly(propylene glycol) and different blocks of polymer that change their hydrophobic/hydrophilic behavior as a function of pH. The polymer chains of the starting material were extended at their functional ends with the pH-sensitive units using ATRP; this mechanism of controlled radical polymerization was chosen because of the need to minimize polydispersity and avoid transfer reactions possibly leading to homopolymeric inpurities. The starting material were modified in order to use them as macroinitiator for ATRP. The kinetic of each ATRP reaction has been investigated, in order to be able to synthesize polymers with different degree of polymerization, stopping the reaction when the desired polymers chain length has been reached. We will use polymer chains with different basicity and degree of polymerization to link any possible effect of their presence to the conditions under which they become hydrophobic. It has been shown that the rate of polymerization changes changing the type of macroinitiator and the type of monomer synthesized. The slowest rate of polymerization is the one with the most hindered monomer synthesized using the macroinitiator with the highest molecular weight. The water solubility of the synthesized polymers changes depending on the pH of the solution and on the structure of the polymers. It has been shown using 1H-NMR that some of the synthesized polymers are capable to self-aggregation in water solution. The self-aggregation and the type of aggregation is influenced from the structure of the polymer and from the pH of the solution. Changing the structure of the polymers and the pH it is possible to obtain different type of aggregates in solution. This aggregates differ for the volume occupied from them, and for their hardness. Rheological measurements have been demonstrated that the synthesized polymers are capable to form gel phases. The gelation temperature changes changing the structure of the aggregates in solution and it is possible to correlate the changing in the gelation temperature with the changing in the structure of the polymer.

Color/kinematic duality, double copies and scalar matrix models

In questa tesi presentiamo una descrizione autoconsistente della dualità Colore/Cinematica nelle teorie di gauge e al processo di Double Copy. Particolare attenzione viene data all'approccio alla dualità con il formalismo di cono-luce, in quanto semplifica notevolmente sia il calcolo sia l'interpretazione fisica: vengono indagati i settori duale e self-duale per poi passare al modello di Chalmers e Siegel per l'estensione alla teoria generale. Proponiamo quindi uno Scalar Matrix Model, che può essere un buon modello per generare ampiezze ottenibili da una Double Copy `inversa', e ne studiamo un'eventuale dualità a la Colore/Cinematica. Vengono illustrati alcuni casi particolari di rottura spontanea di simmetria. In appendice riportiamo un notebook di Mathematica per il calcolo di ampiezze tree level di puro gauge, utile per i calcoli necessari allo studio della dualità.

Espressione della proteina CRM197 in escherichia coli e purificazione mediante cromatografia di affinità

In questo lavoro di tesi sono stati confrontati diversi protocolli per la purificazione della proteina CRM197 mediante cromatografia di affinità a cationi divalenti. Il CRM197 è una variante della tossina difterica caratterizzata da stessa massa molecolare e struttura. A causa di un’unica mutazione (G52E), tale variante è atossica e presenta numerose applicazioni in campo farmaceutico (in particolare nella preparazione di vaccini coniugati). Fino ad ora, per la produzione del CRM197 è stato utilizzato il ceppo originale di derivazione, cioè Corynebacterium diphteriae, e la produzione eterologa nel batterio Escherichia coli ha mostrato notevoli difficoltà. In particolare, mentre è stato possibile definire un valido protocollo di sovraespressione e di estrazione proteica, le fasi successive di purificazione e di refolding (rinaturazione) sono ancora problematiche e causano basse rese finali, ostacolando le prospettive di scale-up su scala industriale. Il CRM197, infatti, per le sue caratteristiche strutturali, come l’elevata percentuale di amminoacidi idrofobici e la presenza di foglietti β esposti al solvente, è suscettibile alla formazione di aggregati insolubili che impone, lungo tutto il processo, il controllo delle interazioni idrofobiche (con agenti denaturanti e/o detergenti). In un precedente lavoro di tesi, è stato sviluppato un protocollo valido per ottenere un’elevata espressione proteica intracellulare. Il primo passaggio di purificazione prevede una cromatografia di affinità su colonna che viene sfruttata anche per eseguire il refolding proteico. Tuttavia, durante la messa a punto di tale processo, sono stati osservati evidenti fenomeni di aggregazione della proteina, oltre all’instaurarsi di legami aspecifici proteina-proteina o proteina-resina cromatografica. In questo lavoro di tesi sono state affrontate alcune problematiche legate a tale passaggio di purificazione per cercare di individuare le condizioni ottimali per ottenere il CRM197 in forma nativa e biologicamente attiva.

Sintesi e caratterizzazione di nuovi politiofeni double-cable per applicazioni fotovoltaiche

In questo lavoro di tesi è stato sintetizzato un nuovo copolimero contenente il gruppo fullerenico in catena laterale. Il copolimero è risultato solubile nei comuni solventi organici e ha dato una efficienza di conversione fotovoltaica in un sistema BHJ del 2.19%.

La struttura della double bubble di area minima

In questa tesi viene presentata una scelta dei passaggi fondamentali per arrivare alla dimostrazione della congettura della double bubble, dovuta ad Hutchings, Morgan, Ritoré e Ros. Questa dimostrazione assicura l'esistenza e l'unicità della superficie minima che permette di racchiudere due volumi nello spazio reale tridimensionale; si tratta quindi di un caso particolare del problema delle bolle di sapone, che ha richiesto la messa a punto di strumenti sofisticati di teoria geometrica della misura, calcolo delle variazioni ed equazioni differenziali non lineari.

Gpu-based many-core architecture emulation: A double level approach

The efficient emulation of a many-core architecture is a challenging task, each core could be emulated through a dedicated thread and such threads would be interleaved on an either single-core or a multi-core processor. The high number of context switches will results in an unacceptable performance. To support this kind of application, the GPU computational power is exploited in order to schedule the emulation threads on the GPU cores. This presents a non trivial divergence issue, since GPU computational power is offered through SIMD processing elements, that are forced to synchronously execute the same instruction on different memory portions. Thus, a new emulation technique is introduced in order to overcome this limitation: instead of providing a routine for each ISA opcode, the emulator mimics the behavior of the Micro Architecture level, here instructions are date that a unique routine takes as input. Our new technique has been implemented and compared with the classic emulation approach, in order to investigate the chance of a hybrid solution.

Simulazione numerica di incollaggi double-strap joint

Esposizione di comportamenti e caratteristiche principali dei giunti incollati. Il metodo agli elementi finiti è stato studiato in modo da realizzare un modello accurato di un sistema fisico. L’analisi agli elementi finiti è stata utilizzata per effettuare una simulazione numerica di un double-strap joint in alluminio e in CFRP sotto un carico di trazione assiale. L’effetto di una modifica della distanza tra le lastre è stato studiato e i risultati confrontati.

A new double laser pulse pumping scheme for transient collisionally excited plasma soft X-ray lasers

Within this thesis a new double laser pulse pumping scheme for plasma-based, transient collisionally excited soft x-ray lasers (SXRL) was developed, characterized and utilized for applications. SXRL operations from ~50 up to ~200 electron volt were demonstrated applying this concept. As a central technical tool, a special Mach-Zehnder interferometer in the chirped pulse amplification (CPA) laser front-end was developed for the generation of fully controllable double-pulses to optimally pump SXRLs.rnThis Mach-Zehnder device is fully controllable and enables the creation of two CPA pulses of different pulse duration and variable energy balance with an adjustable time delay. Besides the SXRL pumping, the double-pulse configuration was applied to determine the B-integral in the CPA laser system by amplifying short pulse replica in the system, followed by an analysis in the time domain. The measurement of B-integral values in the 0.1 to 1.5 radian range, only limited by the reachable laser parameters, proved to be a promising tool to characterize nonlinear effects in the CPA laser systems.rnContributing to the issue of SXRL pumping, the double-pulse was configured to optimally produce the gain medium of the SXRL amplification. The focusing geometry of the two collinear pulses under the same grazing incidence angle on the target, significantly improved the generation of the active plasma medium. On one hand the effect was induced by the intrinsically guaranteed exact overlap of the two pulses on the target, and on the other hand by the grazing incidence pre-pulse plasma generation, which allows for a SXRL operation at higher electron densities, enabling higher gain in longer wavelength SXRLs and higher efficiency at shorter wavelength SXRLs. The observation of gain enhancement was confirmed by plasma hydrodynamic simulations.rnThe first introduction of double short-pulse single-beam grazing incidence pumping for SXRL pumping below 20 nanometer at the laser facility PHELIX in Darmstadt (Germany), resulted in a reliable operation of a nickel-like palladium SXRL at 14.7 nanometer with a pump energy threshold strongly reduced to less than 500 millijoule. With the adaptation of the concept, namely double-pulse single-beam grazing incidence pumping (DGRIP) and the transfer of this technology to the laser facility LASERIX in Palaiseau (France), improved efficiency and stability of table-top high-repetition soft x-ray lasers in the wavelength region below 20 nanometer was demonstrated. With a total pump laser energy below 1 joule the target, 2 mircojoule of nickel-like molybdenum soft x-ray laser emission at 18.9 nanometer was obtained at 10 hertz repetition rate, proving the attractiveness for high average power operation. An easy and rapid alignment procedure fulfilled the requirements for a sophisticated installation, and the highly stable output satisfied the need for a reliable strong SXRL source. The qualities of the DGRIP scheme were confirmed in an irradiation operation on user samples with over 50.000 shots corresponding to a deposited energy of ~ 50 millijoule.rnThe generation of double-pulses with high energies up to ~120 joule enabled the transfer to shorter wavelength SXRL operation at the laser facility PHELIX. The application of DGRIP proved to be a simple and efficient method for the generation of soft x-ray lasers below 10 nanometer. Nickel-like samarium soft x-ray lasing at 7.3 nanometer was achieved at a low total pump energy threshold of 36 joule, which confirmed the suitability of the applied pumping scheme. A reliable and stable SXRL operation was demonstrated, due to the single-beam pumping geometry despite the large optical apertures. The soft x-ray lasing of nickel-like samarium was an important milestone for the feasibility of applying the pumping scheme also for higher pumping pulse energies, which are necessary to obtain soft x-ray laser wavelengths in the water window. The reduction of the total pump energy below 40 joule for 7.3 nanometer short wavelength lasing now fulfilled the requirement for the installation at the high-repetition rate operation laser facility LASERIX.rn