Development and validation of a shipboard system for measuring high-resolution vertical profiles of aqueous dimethylsulfide concentrations using chemical ionization mass spectrometry

A sampling and analytical system has been developed for shipboard measurements of high-resolution vertical profiles of the marine trace gas dimethylsulfide (DMS). The system consists of a tube attached to a CTD with a peristaltic pump on deck that delivers seawater to a membrane equilibrator and atmospheric pressure chemical ionization mass spectrometer (Eq-APCIMS). This allows profiling DMS concentrations to a depth of 50 m, with a depth resolution of 1.3-2 m and a detection limit of nearly 0.1 nmol L-1. The seawater is also plumbed to allow parallel operation of additional continuous instruments, and simultaneous collection of discrete samples for complementary analyses. A valve alternates delivery of seawater from the vertical profiler and the ship�s underway intake, thereby providing high-resolution measurements in both the vertical and horizontal dimensions. Tests conducted on various cruises in the Mediterranean Sea, Atlantic, Indian, and Pacific Oceans show good agreement between the Eq-APCIMS measurements and purge and trap gas chromatography with flame photometric detection (GC-FPD) and demonstrate that the delivery of seawater from the underway pump did not significantly affect endogenous DMS concentrations. Combination of the continuous flow DMS analysis with high-frequency hydrographic, optical, biological and meteorological measurements will greatly improve the spatial/temporal resolution of seagoing measurements and improve our understanding of DMS cycling.

Friedel-Crafts Benzoylation of Anisole in Ionic Liquids: Catalysis, Separation, and Recycle Studies

The comparison of three ionic liquid-mediated catalytic processes for the benzoylation of anisole with benzoic anhydride is presented. A detailed understanding of the mechanism by which the zeolite and metal triflate reactions in bis{trifluoromethanesulfonyl}imide-based ionic liquids has been reported previously, and these routes are considered together with an indium chloride-based ionic liquid system. Solvent extraction and vacuum/steam distillation have been assessed as possible workup procedures, and an overall preliminary economic evaluation of each overall process is reported. Although the predominant activity is associated with the in situ formation of a homogeneous acid catalyst, the low cost and facile separation of the zeolite-catalysed process leads to this route being the most economically viable overall option. The results of a continuous flow miniplant based on the zeolite catalyst are also presented and compared with the reaction using a small plug How reactor.

Validation of the CDC Biofilm Reactor as a Dynamic Model for Assessment of Encrustation Formation on Urological Device Materials

Contemporary medical science is reliant upon the rational selection and utilization of devices, and therefore, an increasing need has developed for in vitro systems aimed at replicating the conditions to which urological devices will be subjected to during their use in vivo. We report the development and validation of a novel continuous flow encrustation model based on the commercially available CDC biofilm reactor. Proteus mirabilis-induced encrustation formation on test biomaterial sections under varying experimental parameters was analyzed by X-ray diffraction, infrared- and Raman spectroscopy and by scanning electron microscopy. The model system produced encrusted deposits similar to those observed in archived clinical samples. Results obtained for the system are highly reproducible with encrustation being rapidly deposited on test biomaterial sections. This model will have utility in the rapid screening of encrustation behavior of biomaterials for use in urological applications. (C) 2010 Wiley Periodicals. Inc. J Biomed Mater Res Part B: Appl Biomater 93B: 128-140, 2010

Diastereoselective 1,3-dipolar cycloaddition of pyrylium ylides with chiral enamides

Chiral enamides5f-i were found to react with pyrylium ylides to give cycloadducts 6d-i in good yields with an excellent level of stereoselectivity. The chiral auxiliary was successfully removed on hydrogenolysis of compound 6f in continuous flow (H-Cube) resulting in the first asymmetric synthesis of complex amine 8.

Accounting for the effects of lipids in stable isotope (δ13C and δ15N values) analysis of skin and blubber of balaenopterid whales

RATIONALE Stable isotope values (d¹³C and d¹⁵N) of darted skin and blubber biopsies can shed light on habitat use and diet of cetaceans, which are otherwise difficult to study. Non-dietary factors affect isotopic variability, chiefly the depletion of C due to the presence of C-rich lipids. The efficacy of post hoc lipid-correction models (normalization) must be tested. METHODS For tissues with high natural lipid content (e.g., whale skin and blubber), chemical lipid extraction or normalization is necessary. C:N ratios, d¹³C values and d¹⁵N values were determined for duplicate control and lipid-extracted skin and blubber of fin (Balaenoptera physalus), humpback (Megaptera novaeangliae) and minke whales (B. acutorostrata) by continuous-flow elemental analysis isotope ratio mass spectrometry (CF-EA-IRMS). Six different normalization models were tested to correct d¹³C values for the presence of lipids. RESULTS Following lipid extraction, significant increases in d¹³C values were observed for both tissues in the three species. Significant increases were also found for d¹⁵N values in minke whale skin and fin whale blubber. In fin whale skin, the d¹⁵N values decreased, with no change observed in humpback whale skin. Non-linear models generally out-performed linear models and the suitability of models varied by species and tissue, indicating the need for high model specificity, even among these closely related taxa. CONCLUSIONS Given the poor predictive power of the models to estimate lipid-free d13C values, and the unpredictable changes in d N values due to lipid-extraction, we recommend against arithmetical normalization in accounting for lipid effects on d13C values for balaenopterid skin or blubber samples. Rather, we recommend that duplicate analysis of lipid-extracted (d13C values) and non-treated tissues (d15N values) be used. Copyright © 2012 John Wiley & Sons, Ltd.

Catalysis in Ionic Liquid-Supercritical CO2 Systems

The combination of ionic liquids (ILs) and supercritical CO2 (scCO2) allows efficient catalytic processes to be developed. Catalyst separation is generally a major challenge when enzymes or homogeneous organometallic catalysts are utilised for reactions, and IL–scCO2 systems address these separation problems, facilitating the recycling or continual use of the catalyst. Typically these systems involve a catalyst being dissolved in an IL and this is where it remains during the process, with scCO2 extracting the products from the IL (catalyst) phase. ILs and many catalysts are not soluble in scCO2 and this facilitates the clean separation of products from the catalyst and IL. When the pressure is reduced in a collection chamber, the scCO2 returns to CO2 gas and products can be obtained without contamination of catalyst or solvents. It is possible to operate IL–scCO2 systems in a continuous flow manner and this further improves the efficiency and industrial potential of these systems. This chapter will introduce the fundamental properties of these multiphase catalytic systems. It will also highlight key examples of catalytic processes from the academic literature which illustrate the benefits of utilising this combination of solvents for catalysis

Relative Contribution of P5 and Hap Surface Proteins to Nontypable Haemophilus influenzae Interplay with the Host Upper and Lower Airways

Nontypable Haemophilus influenzae (NTHi) is a major cause of opportunistic respiratory tract disease, and initiates infection by colonizing the nasopharynx. Bacterial surface proteins play determining roles in the NTHi-airways interplay, but their specific and relative contribution to colonization and infection of the respiratory tract has not been addressed comprehensively. In this study, we focused on the ompP5 and hap genes, present in all H. influenzae genome sequenced isolates, and encoding the P5 and Hap surface proteins, respectively. We employed isogenic single and double mutants of the ompP5 and hap genes generated in the pathogenic strain NTHi375 to evaluate P5 and Hap contribution to biofilm growth under continuous flow, to NTHi adhesion, and invasion/phagocytosis on nasal, pharyngeal, bronchial, alveolar cultured epithelial cells and alveolar macrophages, and to NTHi murine pulmonary infection. We show that P5 is not required for bacterial biofilm growth, but it is involved in NTHi interplay with respiratory cells and in mouse lung infection. Mechanistically, P5NTHi375 is not a ligand for CEACAM1 or α5 integrin receptors. Hap involvement in NTHi375-host interaction was shown to be limited, despite promoting bacterial cell adhesion when expressed in H. influenzae RdKW20. We also show that Hap does not contribute to bacterial biofilm growth, and that its absence partially restores the deficiency in lung infection observed for the ΔompP5 mutant. Altogether, this work frames the relative importance of the P5 and Hap surface proteins in NTHi virulence.

Characterization of nontypable Haemophilus influenzae isolates recovered from adult patients with underlying chronic lung disease reveals genotypic and phenotypic traits associated with persistent infection

Nontypable Haemophilus influenzae (NTHi) has emerged as an important opportunistic pathogen causing infection in adults suffering obstructive lung diseases. Existing evidence associates chronic infection by NTHi to the progression of the chronic respiratory disease, but specific features of NTHi associated with persistence have not been comprehensively addressed. To provide clues about adaptive strategies adopted by NTHi during persistent infection, we compared sequential persistent isolates with newly acquired isolates in sputa from six patients with chronic obstructive lung disease. Pulse field gel electrophoresis (PFGE) identified three patients with consecutive persistent strains and three with new strains. Phenotypic characterisation included infection of respiratory epithelial cells, bacterial self-aggregation, biofilm formation and resistance to antimicrobial peptides (AMP). Persistent isolates differed from new strains in showing low epithelial adhesion and inability to form biofilms when grown under continuous-flow culture conditions in microfermenters. Self-aggregation clustered the strains by patient, not by persistence. Increasing resistance to AMPs was observed for each series of persistent isolates; this was not associated with lipooligosaccharide decoration with phosphorylcholine or with lipid A acylation. Variation was further analyzed for the series of three persistent isolates recovered from patient 1. These isolates displayed comparable growth rate, natural transformation frequency and murine pulmonary infection. Genome sequencing of these three isolates revealed sequential acquisition of single-nucleotide variants in the AMP permease sapC, the heme acquisition systems hgpB, hgpC, hup and hxuC, the 3-deoxy-D-manno-octulosonic acid kinase kdkA, the long-chain fatty acid transporter ompP1, and the phosphoribosylamine glycine ligase purD. Collectively, we frame a range of pathogenic traits and a repertoire of genetic variants in the context of persistent infection by NTHi.

Avaliação técnica e econômica de um biodigestor de fluxo tubular: estudo de caso do modelo implantado na etec "orlando quagliato" em Santa Cruz do Rio Pardo, SP

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Estudo e desenvolvimento de sistema de cobrança de portagens baseado em NFC

Tese para obter o grau de Mestre em Engenharia Electrónica e Telecomunicações

In situ evaluation of single-cell lysis by cytosol extraction observation through fluorescence decay and dielectrophoretic trapping time

We present a new method for lysis of single cells in continuous flow, where cells are sequentially trapped, lysed and released in an automatic process. Using optimized frequencies, dielectrophoretic trapping allows exposing cells in a reproducible way to high electrical fields for long durations, thereby giving good control on the lysis parameters. In situ evaluation of cytosol extraction on single cells has been studied for Chinese hamster ovary (CHO) cells through out-diffusion of fluorescent molecules for different voltage amplitudes. A diffusion model is proposed to correlate this out-diffusion to the total area of the created pores, which is dependent on the potential drop across the cell membrane and enables evaluation of the total pore area in the membrane. The dielectrophoretic trapping is no longer effective after lysis because of the reduced conductivity inside the cells, leading to cell release. The trapping time is linked to the time required for cytosol extraction and can thus provide additional validation of the effective cytosol extraction for non-fluorescent cells. Furthermore, the application of one single voltage for both trapping and lysis provides a fully automatic process including cell trapping, lysis, and release, allowing operating the device in continuous flow without human intervention.

Mechanical circulatory support for destination therapy.

Patients with chronic heart failure who are not eligible for heart transplant and whose life expectancy depends mainly on the heart disease may benefit from mechanical circulatory support. Mechanical circulatory support restores adequate cardiac output and organ perfusion and eventually improves patients' clinical condition, quality of life and life expectancy. This treatment is called destination therapy (DT) and we estimate that in Switzerland more than 120 patients per year could benefit from it. In the last 10 years, design of the devices, implantation techniques and prognoses have changed dramatically. The key to successful therapy with a left ventricular assist device is appropriate patient selection, although we are still working on the definition of reliable inclusion and exclusion criteria and optimal timing for surgical implantation. Devices providing best long-term results are continuous flow, rotary or axial blood pumps implanted using minimally invasive techniques on a beating heart. These new devices (Thoratec HeartMate II and HeartWare HVAD) have only a single moving part, and have improved durability with virtually 10 years freedom from mechanical failure. In selected patients, the overall actuarial survival of DT patients is 75% at 1 year and 62% at 2 years, with a clear improvement in quality of life compared with medical management only. Complications include bleeding and infections; their overall incidence is significantly lower than with previous devices and their management is well defined. DT is evolving into an effective and reasonably cost-effective treatment option for a growing population of patients not eligible for heart transplant, showing encouraging survival rates at 2 years and providing clear improvement in quality of life. The future is bright for people suffering from chronic heart failure.

Hydroxylation d’halogénures d’aryle utilisant la chimie en flux continu et développement d’une nouvelle méthodologie de synthèse de 3-aminoindazoles

L’attrait des compagnies pharmaceutiques pour des structures cycliques possédant des propriétés biologiques intéressantes par les compagnies pharmaceutiques a orienté les projets décrits dans ce mémoire. La synthèse rapide, efficace, verte et économique de ces structures suscite de plus en plus d’attention dans la littérature en raison des cibles biologiques visées qui deviennent de plus en plus complexes. Ce mémoire se divise en deux projets ciblant la synthèse de deux structures aromatiques importantes dans le monde de la chimie médicinale. Dans un premier temps, l’amélioration de la synthèse de dérivés phénoliques a été réalisée. L’apport de la chimie en flux continu dans le développement de voies synthétiques plus vertes et efficaces sera tout d’abord discuté. Ensuite, une revue des antécédents concernant l’hydroxylation d’halogénure d’aryle sera effectuée. Finalement, le développement d’une nouvelle approche rapide de synthèse des phénols utilisant la chimie en flux continu sera présenté, suivi d’un survol de ses avantages et ses limitations. Dans un deuxième temps, le développement d’une nouvelle méthodologie pour la formation de 3-aminoindazoles a été réalisé. Tout d’abord, un résumé de la littérature sur la synthèse de différents indazoles sera présenté. Ensuite, une présentation de deux méthodes efficaces d’activation de liens sera effectuée, soit l’activation d’amides par l’anhydride triflique et l’activation de liens C–H catalysée par des métaux de transition. Finalement, le développement d’une nouvelle méthodologie pour la synthèse de 3-aminoindazole utilisant ces deux approches sera discuté.

Réaction de photocyclodéshydrogénation par catalyse photorédox

Cette thèse présente une nouvelle méthode pour accomplir la réaction de Mallory en utilisant la lumière visible. Pour atteindre ce but, la chimie photorédox qui s'est développée ces dernières années permettra une utilisation efficace de la lumière visible. De plus, la chimie en flux continu sera utilisé afin d'augmenter la surface irradiée du mélange réactionnel. Au cours de ces travaux, une nouvelle méthodologie photochimique utilisant un photocatalyseur de cuivre avec la lumière visible a été efficace pour la synthèse du 5hélicène. Un mécanisme de désactivation oxydante est proposé pour cette réaction. Par ailleurs, cette nouvelle méthodologie a été utilisée pour la synthèse d'un dérivé du 5hélicène et d'un 4hélicène-pyrène hybride. Par la suite, la méthodologie photochimique utilisant un photocatalyseur de cuivre avec la lumière visible a servi à la synthèse de divers carbazoles substitués au niveau de l'azote par des groupements aryles et alkyles. Au cours de cette synthèse, la réaction a révélé un problème de régiosélectivité. Ce dernier a été étudié par la synthèse de nouvelles triarylamines. Finalement, il a été découvert que l'utilisation d'un photocatalyseur de fer peut remplacer le photocatalyseur de cuivre en utilisant l'oxygène comme oxydant pour la synthèse de 9-phénylcarbazole.

Development of a Phase Separation Strategy in Macrocyclization Reactions

La réaction de macrocyclisation est une transformation fondamentale en chimie organique de synthèse. Le principal défi associcé à la formation de macrocycles est la compétition inhérente avec la réaction d’oligomérisation qui mène à la formation de sousproduits indésirables. De plus, l’utilisation de conditions de dilutions élevées qui sont nécessaires afin d’obtenir une cyclisation “sélective”, sont souvent décourageantes pour les applications à l’échelle industrielle. Malgré cet intérêt pour les macrocycles, la recherche visant à développer des stratégies environnementalement bénignes, qui permettent d’utiliser des concentrations normales pour leur synthèse, sont encore rares. Cette thèse décrit le développement d’une nouvelle approche générale visant à améliorer l’efficacité des réactions de macrocyclisation en utilisant le contrôle des effets de dilution. Une stratégie de “séparation de phase” qui permet de réaliser des réactions à des concentrations plus élevées a été developpée. Elle se base sur un mélange de solvant aggrégé contrôlé par les propriétés du poly(éthylène glycol) (PEG). Des études de tension de surface, spectroscopie UV et tagging chimique ont été réalisées afin d’élucider le mécanisme de “séparation de phase”. Il est proposé que celui-ci fonctionne par diffusion lente du substrat organique vers la phase ou le catalyseur est actif. La nature du polymère co-solvant joue donc un rôle crutial dans le contrôle de l’aggrégation et de la catalyse La stratégie de “séparation de phase” a initiallement été étudiée en utilisant le couplage oxidatif d’alcynes de type Glaser-Hay co-catalysé par un complexe de cuivre et de nickel puis a été transposée à la chimie en flux continu. Elle fut ensuite appliquée à la cycloaddition d’alcynes et d’azotures catalysée par un complexe de cuivre en “batch” ainsi qu’en flux continu.