Study of the antioxidant fraction in edible olive oils obtained from different technological systems and parameters

Questo lavoro di tesi è stato suddiviso in tre parti. L’argomento principale è stato lo “Studio della componente antiossidante di oli ottenuti da olive mediante l’utilizzo di diversi sistemi e parametri tecnologici”. E’ ben noto come la qualità ossidativa di un olio di oliva dipenda oltre che dalla sua composizione in acidi grassi, dalla presenza di composti caratterizzati da un elevata attività antiossidante, ovvero le sostanze fenoliche. I composti fenolici contribuiscono quindi in maniera preponderante alla shelf life dell’olio extravergine di oliva. Inoltre sono state riscontrate delle forti correlazione tra alcune di queste sostanze e gli attributi sensoriali positivi di amaro e piccante. E’ poi da sottolineare come il potere antiossidante dei composti fenolici degli oli vergini di oliva, sia stato negli ultimi anni oggetto di considerevole interesse, poiché correlato alla protezione da alcune patologie come ad esempio quelle vascolari, degenerative e tumorali. Il contenuto delle sostanze fenoliche negli oli di oliva dipende da diversi fattori: cultivar, metodo di coltivazione, grado di maturazione delle olive e ovviamente dalle operazioni tecnologiche poiché possono variare il quantitativo di questi composti estratto. Alla luce di quanto appena detto abbiamo valutato l’influenza dei fattori agronomici (metodi di agricoltura biologica, integrata e convenzionale) e tecnologici (riduzione della temperatura della materia prima, aggiunta di coadiuvanti in fase di frangitura e di gramolatura, confronto tra tre oli extravergini di oliva ottenuti mediante diversi sistemi tecnologici) sul contenuto in composti fenolici di oli edibili ottenuti da olive (paper 1-3-4). Oltre alle sostanze fenoliche, negli oli di oliva sono presenti altri composti caratterizzati da proprietà chimiche e nutrizionali, tra questi vi sono i fitosteroli, ovvero gli steroli tipici del mondo vegetale, che rappresentano la frazione dell’insaponificabile quantitativamente più importante dopo gli idrocarburi. La composizione quali-quantitativa degli steroli di un olio di oliva è una delle caratteristiche analitiche più importanti nella valutazione della sua genuinità; infatti la frazione sterolica è significativamente diversa in funzione dell’origine botanica e perciò viene utilizzata per distinguere tra di loro gli oli e le loro miscele. Il principale sterolo nell’olio di oliva è il β- sitosterolo, la presenza di questo composto in quantità inferiore al 90% è un indice approssimativo dell’aggiunta di un qualsiasi altro olio. Il β-sitosterolo è una sostanza importante dal punto di vista della salute, poiché si oppone all’assorbimento del colesterolo. Mentre in letteratura si trovano numerosi lavori relativi al potere antiossidante di una serie di composti presenti nell’olio vergine di oliva (i già citati polifenoli, ma anche carotenoidi e tocoferoli) e ricerche che dimostrano invece come altri composti possano promuovere l’ossidazione dei lipidi, per quanto riguarda il potere antiossidante degli steroli e dei 4- metilsteroli, vi sono ancora poche informazioni. Per questo è stata da noi valutata la composizione sterolica in oli extravergini di oliva ottenuti con diverse tecnologie di estrazione e l’influenza di questa sostanza sulla loro stabilità ossidativa (paper 2). E’ stato recentemente riportato in letteratura come lipidi cellulari evidenziati attraverso la spettroscopia di risonanza nucleare magnetica (NMR) rivestano una importanza strategica da un punto di vista funzionale e metabolico. Questi lipidi, da un lato un lato sono stati associati allo sviluppo di cellule neoplastiche maligne e alla morte cellulare, dall’altro sono risultati anche messaggeri di processi benigni quali l’attivazione e la proliferazione di un normale processo di crescita cellulare. Nell’ambito di questa ricerca è nata una collaborazione tra il Dipartimento di Biochimica “G. Moruzzi” ed il Dipartimento di Scienze degli Alimenti dell’Università di Bologna. Infatti, il gruppo di lipochimica del Dipartimento di Scienze degli Alimenti, a cui fa capo il Prof. Giovanni Lercker, da sempre si occupa dello studio delle frazioni lipidiche, mediante le principali tecniche cromatografiche. L’obiettivo di questa collaborazione è stato quello di caratterizzare la componente lipidica totale estratta dai tessuti renali umani sani e neoplastici, mediante l’utilizzo combinato di diverse tecniche analitiche: la risonanza magnetica nucleare (1H e 13C RMN), la cromatografia su strato sottile (TLC), la cromatografia liquida ad alta prestazione (HPLC) e la gas cromatografia (GC) (paper 5-6-7)

Ultrafeine Aerosolpartikel in der Stratosphäre

Ein neu konstruierter Kondensationskernzähler COPAS (COndensation PArticle counting System) für in-situ-Messungen der Konzentration von Aitken-Teilchen und ultrafeinen Aerosolpartikeln wurde im Rahmen dieser Arbeit erstmals erfolgreich bei Flugzeugmessungen eingesetzt. COPAS ist ein für flugzeuggestützte Messungen an Bord des Forschungsflugzeuges „Geophysica“ in der oberen Troposphäre und unteren Stratosphäre angepaßtes und voll automatisiertes System. Die Verfahrensweise, die Aerosolpartikel des Größenbereichs mit Durchmessern d < 100 nm zum Anwachsen zu bringen, um sie mittels optischer Detektion zu erfassen, ist im COPAS durch das Prinzip der thermischen Diffusion realisiert, wodurch eine kontinuierliche Messung der Aerosolkonzentration mit der untersten Nachweisgrenze für Partikeldurchmesser von d = 6 nm gewährleistet ist. Durch die Verwendung einer Aerosolheizung ist die Unterscheidung von volatilem und nichtvolatilem Anteil des Aerosols mit COPAS möglich. In umfassenden Laborversuchen wurde das COPAS-System hinsichtlich der unteren Nachweisgrenze in Abhängigkeit von der Betriebstemperatur und bei verschiedenen Druckbedingungen charakterisiert sowie die Effizienz der Aerosolheizung bestimmt. Flugzeuggestützte Messungen fanden in mittleren und polaren Breiten im Rahmen des EUPLEX-/ENVISAT-Validierungs–Projektes und in den Tropen während der TROCCINOX/ENVISAT-Kampagne statt. Die Messungen der vertikalen Konzentrationsverteilung des Aerosols ergaben in polaren Breiten eine Zunahme der Konzentration oberhalb von 17 km innerhalb des polaren Vortex mit hohem Anteil nichtvolatiler Partikel von bis zu 70 %. Als Ursache hierfür wird der Eintrag von meteoritischen Rauchpartikeln aus der Mesosphäre in die obere und mittlere Stratosphäre des Vortex angesehen. Ferner konnte in der unteren Stratosphäre des polaren Vortex der Einfluß troposphärischer Luft aus niedrigen Breiten festgestellt werden, die sich in einer hohen Variabilität der Aerosolpartikelkonzentration manifestiert. In tropischen Breiten wurde die Tropopausenregion untersucht. Dabei wurden Konzentrationen von bis zu 104 ultrafeiner Aerosolpartikel mit 6 nm < d < 14 nm pro cm-3 Luft gemessen, deren hoher volatiler Anteil einen sicheren Hinweis darauf gibt, daß die Partikel durch den Prozeß der homogenen Nukleation gebildet wurden. Damit konnte erstmals die Schlußfolgerungen von Brock et al. (1995) durch direkte Messungen der ultrafeinen Partikelkonzentration weitergehend belegt werden, daß in der tropischen Tropopausenregion die Neubildung von Aerosolpartikeln durch homogene Nukleation stattfindet. Die vertikalen Verteilungen der stratosphärischen Aerosolpartikelkonzentration mittlerer Breiten verdeutlichen die Ausbildung einer über 6 Jahre hinweg nahezu konstanten Hintergrundkonzentration des stratosphärischen Aerosols unter vulkanisch unbeeinflußten Bedingungen. Ferner gibt die vergleichende Untersuchung der stratosphärischen Aerosolpartikelkonzentration aus polaren, mittleren und tropischen Breiten Aufschluß über den Transport und die Prozessierung des stratosphärischen Aerosols und insbesondere über den Austausch von Luftmassen zwischen der Stratosphäre und der Troposphäre.

Constraints on neutrino mass fraction using Redshift Space Distortions

Redshift Space Distortions (RSD) are an apparent anisotropy in the distribution of galaxies due to their peculiar motion. These features are imprinted in the correlation function of galaxies, which describes how these structures distribute around each other. RSD can be represented by a distortions parameter $\beta$, which is strictly related to the growth of cosmic structures. For this reason, measurements of RSD can be exploited to give constraints on the cosmological parameters, such us for example the neutrino mass. Neutrinos are neutral subatomic particles that come with three flavours, the electron, the muon and the tau neutrino. Their mass differences can be measured in the oscillation experiments. Information on the absolute scale of neutrino mass can come from cosmology, since neutrinos leave a characteristic imprint on the large scale structure of the universe. The aim of this thesis is to provide constraints on the accuracy with which neutrino mass can be estimated when expoiting measurements of RSD. In particular we want to describe how the error on the neutrino mass estimate depends on three fundamental parameters of a galaxy redshift survey: the density of the catalogue, the bias of the sample considered and the volume observed. In doing this we make use of the BASICC Simulation from which we extract a series of dark matter halo catalogues, characterized by different value of bias, density and volume. This mock data are analysed via a Markov Chain Monte Carlo procedure, in order to estimate the neutrino mass fraction, using the software package CosmoMC, which has been conveniently modified. In this way we are able to extract a fitting formula describing our measurements, which can be used to forecast the precision reachable in future surveys like Euclid, using this kind of observations.

Complementary mass spectrometric techniques for the characterization of the organic fraction in atmospheric aerosols

Aerosol particles are strongly related to climate, air quality, visibility and human health issues. They contribute the largest uncertainty in the assessment of the Earth´s radiative budget, directly by scattering or absorbing solar radiation or indirectly by nucleating cloud droplets. The influence of aerosol particles on cloud related climatic effects essentially depends upon their number concentration, size and chemical composition. A major part of submicron aerosol consists of secondary organic aerosol (SOA) that is formed in the atmosphere by the oxidation of volatile organic compounds. SOA can comprise a highly diverse spectrum of compounds that undergo continuous chemical transformations in the atmosphere.rnThe aim of this work was to obtain insights into the complexity of ambient SOA by the application of advanced mass spectrometric techniques. Therefore, an atmospheric pressure chemical ionization ion trap mass spectrometer (APCI-IT-MS) was applied in the field, facilitating the measurement of ions of the intact molecular organic species. Furthermore, the high measurement frequency provided insights into SOA composition and chemical transformation processes on a high temporal resolution. Within different comprehensive field campaigns, online measurements of particular biogenic organic acids were achieved by combining an online aerosol concentrator with the APCI-IT-MS. A holistic picture of the ambient organic aerosol was obtained through the co-located application of other complementary MS techniques, such as aerosol mass spectrometry (AMS) or filter sampling for the analysis by liquid chromatography / ultrahigh resolution mass spectrometry (LC/UHRMS).rnIn particular, during a summertime field study at the pristine boreal forest station in Hyytiälä, Finland, the partitioning of organic acids between gas and particle phase was quantified, based on the online APCI-IT-MS and AMS measurements. It was found that low volatile compounds reside to a large extent in the gas phase. This observation can be interpreted as a consequence of large aerosol equilibration timescales, which build up due to the continuous production of low volatile compounds in the gas phase and/or a semi-solid phase state of the ambient aerosol. Furthermore, in-situ structural informations of particular compounds were achieved by using the MS/MS mode of the ion trap. The comparison to MS/MS spectra from laboratory generated SOA of specific monoterpene precursors indicated that laboratory SOA barely depicts the complexity of ambient SOA. Moreover, it was shown that the mass spectra of the laboratory SOA more closely resemble the ambient gas phase composition, indicating that the oxidation state of the ambient organic compounds in the particle phase is underestimated by the comparison to laboratory ozonolysis. These observations suggest that the micro-scale processes, such as the chemistry of aerosol aging or the gas-to-particle partitioning, need to be better understood in order to predict SOA concentrations more reliably.rnDuring a field study at the Mt. Kleiner Feldberg, Germany, a slightly different aerosol concentrator / APCI-IT-MS setup made the online analysis of new particle formation possible. During a particular nucleation event, the online mass spectra indicated that organic compounds of approximately 300 Da are main constituents of the bulk aerosol during ambient new particle formation. Co-located filter analysis by LC/UHRMS analysis supported these findings and furthermore allowed to determine the molecular formulas of the involved organic compounds. The unambiguous identification of several oxidized C 15 compounds indicated that oxidation products of sesquiterpenes can be important compounds for the initial formation and subsequent growth of atmospheric nanoparticles.rnThe LC/UHRMS analysis furthermore revealed that considerable amounts of organosulfates and nitrooxy organosulfates were detected on the filter samples. Indeed, it was found that several nitrooxy organosulfate related APCI-IT-MS mass traces were simultaneously enhanced. Concurrent particle phase ion chromatography and AMS measurements indicated a strong bias between inorganic sulfate and total sulfate concentrations, supporting the assumption that substantial amounts of sulfate was bonded to organic molecules.rnFinally, the comprehensive chemical analysis of the aerosol composition was compared to the hygroscopicity parameter kappa, which was derived from cloud condensation nuclei (CCN) measurements. Simultaneously, organic aerosol aging was observed by the evolution of a ratio between a second and a first generation biogenic oxidation product. It was found that this aging proxy positively correlates with increasing hygroscopicity. Moreover, it was observed that the bonding of sulfate to organic molecules leads to a significant reduction of kappa, compared to an internal mixture of the same mass fractions of purely inorganic sulfate and organic molecules. Concluding, it has been shown within this thesis that the application of modern mass spectrometric techniques allows for detailed insights into chemical and physico-chemical processes of atmospheric aerosols.rn

The gas mass fraction and the dynamical state in x-ray luminous clusters of galaxies at low redshift

Gli ammassi di galassie sono le strutture gravitazionalmente legate con le più profonde buche di potenziale, pertanto è previsto che questi contengano una frazione di barioni non molto diversa da quella cosmologica. Con l’introduzione di modelli sempre più accurati di fisica barionica all’interno di simulazioni idrodinamiche è stato possibile predire la percentuale cosmica di barioni presente negli ammassi di galassie. Unendo questi modelli previsionali con misure della frazione di gas in ammassi e informazioni sulla densità di barioni dell’Universo si può ottenere una stima della densità di materia cosmica Ωm. L'obiettivo di questo lavoro di Tesi è la stima di Ωm a partire dalla frazione di gas osservata in questi sistemi. Questo lavoro era stato già fatto in precedenza, ma tenendo in considerazione solo gli ammassi più massivi e dinamicamente rilassati. Usando parametri che caratterizzano la morfologia della distribuzione di brillanza superficiale nei raggi X, abbiamo classificato i nostri oggetti come rilassati o disturbati, laddove presentassero evidenze di recenti attività di interazione. Abbiamo dunque valutato l’impatto degli oggetti disturbati sulla stima del parametro cosmologico Ωm, computando il Chi2 tra la frazione di massa barionica nell’Universo e quella da noi ricavata. Infine abbiamo investigato una relazione tra il valore della frazione di gas degli ammassi rilassati e quello dei disturbati, in modo da correggere quindi questi ultimi, riportandoli nei dintorni del valore medio per i rilassati e usarli per ampliare il campione e porre un vincolo più stringente su Ωm. Anche con il limitato campione a nostra disposizione, è stato possibile porre un vincolo più stretto su Ωm, utilizzando un maggior numero di oggetti e riducendo così l’errore statistico.

Synthesis, characterization and catalytic performances of ruthenium-based catalysts for the acceptorless dehydrogenative coupling of butanol

A growing interest towards new sources of energy has led in recent years to the development of a new generation of catalysts for alcohol dehydrogenative coupling (ADC). This green, atom-efficient reaction is capable of turning alcohol derivatives into higher value and chemically more attractive ester molecules, and it finds interesting applications in the transformation of the large variety of products deriving from biomass. In the present work, a new series of ruthenium-PNP pincer complexes are investigated for the transformation of 1-butanol, one of the most challenging substrates for this type of reactions, into butyl butyrate, a short-chain symmetrical ester widely used in flavor industries. Since the reaction kinetics depends on hydrogen diffusion, the study aimed at identifying proper reactor type and right catalyst concentration to avoid mass transfer interferences and to get dependable data. A comparison between catalytic activities and productivities has been made to establish the role of the different ligands bonded both to the PNP binder and to the ruthenium metal center, and hence to find the best catalyst for this type of reaction.

Assessment of right ventricular systolic function: Comparison between cardiac magnetic resonance derived ejection fraction and pulsed-wave tissue Doppler imaging of the tricuspid annulus

Systolic right ventricular (RV) function is an important predictor in the course of various congenital and acquired heart diseases. Its practical determination by echocardiography remains challenging. We compared routine assessment of lateral tricuspid annular systolic motion velocity (TV(lat), cm/s) using pulsed-wave tissue Doppler imaging from the apical 4-chamber view with cardiac magnetic resonance (CMR) as reference method.

Clinical outcome of high-risk patients with severe aortic stenosis and reduced left ventricular ejection fraction undergoing medical treatment or TAVI

Introduction Reduced left ventricular function in patients with severe symptomatic valvular aortic stenosis is associated with impaired clinical outcome in patients undergoing surgical aortic valve replacement (SAVR). Transcatheter Aortic Valve Implantation (TAVI) has been shown non-inferior to SAVR in high-risk patients with respect to mortality and may result in faster left ventricular recovery. Methods We investigated clinical outcomes of high-risk patients with severe aortic stenosis undergoing medical treatment (n = 71) or TAVI (n = 256) stratified by left ventricular ejection fraction (LVEF) in a prospective single center registry. Results Twenty-five patients (35%) among the medical cohort were found to have an LVEF≤30% (mean 26.7±4.1%) and 37 patients (14%) among the TAVI patients (mean 25.2±4.4%). Estimated peri-interventional risk as assessed by logistic EuroSCORE was significantly higher in patients with severely impaired LVEF as compared to patients with LVEF>30% (medical/TAVI 38.5±13.8%/40.6±16.4% versus medical/TAVI 22.5±10.8%/22.1±12.8%, p <0.001). In patients undergoing TAVI, there was no significant difference in the combined endpoint of death, myocardial infarction, major stroke, life-threatening bleeding, major access-site complications, valvular re-intervention, or renal failure at 30 days between the two groups (21.0% versus 27.0%, p = 0.40). After TAVI, patients with LVEF≤30% experienced a rapid improvement in LVEF (from 25±4% to 34±10% at discharge, p = 0.002) associated with improved NYHA functional class at 30 days (decrease ≥1 NYHA class in 95%). During long-term follow-up no difference in survival was observed in patients undergoing TAVI irrespective of baseline LVEF (p = 0.29), whereas there was a significantly higher mortality in medically treated patients with severely reduced LVEF (log rank p = 0.001). Conclusion TAVI in patients with severely reduced left ventricular function may be performed safely and is associated with rapid recovery of systolic left ventricular function and heart failure symptoms.

Value of age, creatinine, and ejection fraction (ACEF score) in assessing risk in patients undergoing percutaneous coronary interventions in the 'All-Comers' LEADERS trial

Background— The age, creatinine, and ejection fraction (ACEF) score (age/left ventricular ejection fraction+1 if creatinine >2.0 mg/dL) has been established as an effective predictor of clinical outcomes in patients undergoing elective coronary artery bypass surgery; however, its utility in “all-comer” patients undergoing percutaneous coronary intervention is yet unexplored. Methods and Results— The ACEF score was calculated for 1208 of the 1707 patients enrolled in the LEADERS trial. Post hoc analysis was performed by stratifying clinical outcomes at the 1-year follow-up according to ACEF score tertiles: ACEFlow ≤1.0225, 1.0225< ACEFmid ≤1.277, and ACEFhigh >1.277. At 1-year follow-up, there was a significantly lower number of patients with major adverse cardiac event–free survival in the highest tertile of the ACEF score (ACEFlow=92.1%, ACEFmid=89.5%, and ACEFhigh=86.1%; P=0.0218). Cardiac death was less frequent in ACEFlow than in ACEFmid and ACEFhigh (0.7% vs 2.2% vs 4.5%; hazard ratio=2.22, P=0.002) patients. Rates of myocardial infarction were significantly higher in patients with a high ACEF score (6.7% for ACEFhigh vs 5.2% for ACEFmid and 2.5% for ACEFlow; hazard ratio=1.6, P=0.006). Clinically driven target-vessel revascularization also tended to be higher in the ACEFhigh group, but the difference among the 3 groups did not reach statistical significance. The rate of composite definite, possible, and probable stent thrombosis was also higher in the ACEFhigh group (ACEFlow=1.2%, ACEFmid=3.5%, and ACEFhigh=6.2%; hazard ratio=2.04, P<0.001). Conclusions— ACEF score may be a simple way to stratify risk of events in patients treated with percutaneous coronary intervention with respect to mortality and risk of myocardial infarction.

Fluctuation phenotyping based on daily fraction of exhaled nitric oxide values in asthmatic children

Fraction of exhaled nitric oxide (Feno), a marker of airway inflammation, has been proposed to be useful for asthma management, but conclusions are inconsistent. This might be due to the failure of mean statistics to characterize individual variability in Feno values, which is possibly a better indicator of asthma control than single measurements.

Effects of right ventricular pacing on left ventricular ejection fraction in a pacemaker clinic

The aim of this study was to evaluate whether a change of left ventricular ejection fraction (LVEF) depending on percentage of right ventricular pacing is found in a real-life setting of a pacemaker clinic.

Importance of the sampled milk fraction for the prediction of total quarter somatic cell count

This study investigated the changes in somatic cell counts (SCC) in different fractions of milk, with special emphasis on the foremilk and cisternal milk fractions. Therefore, in Experiment 1, quarter milk samples were defined as strict foremilk (F), cisternal milk (C), first 400 g of alveolar milk (A1), and the remaining alveolar milk (A2). Experiment 2 included 6 foremilk fractions (F1 to F6), consisting of one hand-stripped milk jet each, and the remaining cisternal milk plus the entire alveolar milk (RM). In Experiment 1, changes during milking indicated the importance of the sampled milk fraction for measuring SCC because the decrease in the first 3 fractions (F, C, and A1) was enormous in milk with high total quarter SCC. The decline in SCC from F to C was 50% and was 80% from C to A1. Total quarter SCC presented a value of approximately 20% of SCC in F or 35% of SCC in C. Changes in milk with low or very low SCC were marginal during milking. Fractions F and C showed significant differences in SCC among different total SCC concentrations. These differences disappeared with the alveolar fractions A1 and A2. In Experiment 2, a more detailed investigation of foremilk fractions supported the findings of Experiment 1. A significant decline in the foremilk fractions even of F1 to F6 was observed in high-SCC milk at concentrations >350 x 10(3) cells/mL. Although one of these foremilk fractions presented only 0.1 to 0.2% of the total milk, the SCC was 2- to 3-fold greater than the total quarter milk SCC. Because the trait of interest (SCC) was measured directly by using the DeLaval cell counter (DCC), the quality of measurement was tested. Statistically interesting factors (repeatability, recovery rate, and potential matrix effects of milk) proved that the DCC is a useful tool for identifying the SCC of milk samples, and thus of grading udder health status. Generally, the DCC provides reliable results, but one must consider that SCC even in strict foremilk can differ dramatically from SCC in the total cisternal fraction, and thus also from SCC in the alveolar fraction.