Cigarette smoke displays both immunoactivating and immunosuppressive activities. Although the health risks of cigarette smoke are widely reported, the impact and mechanism of cigarette smoke exposure on inflammatory diseases are still unclear. Innate immune responses could be activated shortly after influenza A virus infection and then trigger inflammation in the lung. Until now, the effect of prior cigarette smoke on the inflammation caused by the following influenza A virus infection has not been fully understood and there is no study about the role of cigarette smoke in 2009 pandemic H1N1 (pdmH1N1) and avian H9N2 (H9N2/G1) infection. In this study, C57/B6N mice were whole body exposed to 4% cigarette smoke 4 hours per day for 21 days and then infected with pdmH1N1 or H9N2 virus. Some mice were exposed to room air in parallel as the control. Nicotine was also used to mimic the effect of the cigarette smoke. Human lung adenocarcinoma epithelial cell line A549 or human monocyte-derived macrophages were pre-treated with 10μM nicotine, and then infected with pdmH1N1 or H9N2 virus. The expression of cytokines and chemokines was examined in the supernatant. C57/B6N mice were treated with 24mg/kg/day nicotine or sterile water subcutaneously for 21 days and then infected with pdmH1N1 or H9N2 virus. Survival, body weight changes, lung viral loads, inflammatory responses and immune cells that infiltrated into the lung were analyzed. Cigarette smoke exposure alone significantly up-regulated the lung inflammation, confirmed by the dramatically decreased body weight gain and increased inflammatory response compared with the control mice. Such prior cigarette smoke exposure significantly reduced the disease severity induced by subsequent pdmH1N1 or H9N2 virus infection. For pdmH1N1 infection, cigarette smoke exposure group had a significantly lower mortality than the control group, which might be due to the lower inflammatory response at day 5 post virus infection. Similarly, after H9N2 virus infection, the mice in cigarette smoke exposure group displayed a significantly milder disease, as evidenced by less weight loss, weaker inflammatory response as well as lower number of immune cells infiltrating into the lung compared to the control group. There was no difference for the lung viral loads between the two groups upon both pdmH1N1 and H9N2 virus infection. Besides, pre-treating the A549 and primary human macrophages with nicotine decreased the expression of some cytokines and chemokines after pdmH1N1 or H9N2 virus infection. The mice treated with nicotine displayed significantly less weight loss and lower inflammatory response than control mice treated with sterile water upon pdmH1N1 or H9N2 virus infection. Collectively, our study demonstrated that the immunosuppressive effect of cigarette smoke was responsible for amelioration of pdmH1N1 and H9N2 pathogenicity by dampening the hyper-reaction of inflammatory response without any direct effect on viral replication. Nicotine, an anti-inflammatory factor, was the key component in cigarette smoke that was responsible for this immunosuppressive effect. Our study provided the first in vivo evidence that cigarette smoke, mostly due to nicotine, could protect against the pathogenicity of not only pdmH1N1, but also H9N2 virus. / published_or_final_version / Paediatrics and Adolescent Medicine / Doctoral / Doctor of Philosophy

In recent years, much attention has been focused on the application of alternutive gaseoas fuels, particularly natural gas (lVG), to diesel engines. This is due to the promisiog results obtained from the resesrch on NG as an internal combustion engine fuel throughout the world which hus shown that there is potential fo, minimizing air pollution and noise by replacing diesel fuel in existing engines by lfc fuel. For partial substitution of diesel fuel with IfG fuel in a diesel engine, a mixed combustion process called daal-fuelling approach has been adopted. Dual fuelling is the method whereby an alternative gaseous fuel such as IYG is induced into the cylinder as a primary fuel, with oir, and is subsequently ignited with a pilot injection of diesel fael. Extensive tests on emissions, performonce and dilferent umounts of NG substitution in a direct injection (DI) diesel engine have been carried out fo, both diesel fuel only and dual fuel (DF) operations. The results show that 86 % NG could be substituted for diesel fuel at low speeds over the whole load range. Maximum IfG operotion showed higher corbon monoxide (CO) emissions than the diesel fuel only operution while smoke was reduced with DF operation. The maximum vulues of smoke emission were 30 Hutridge smoke numbers (HSIV) with the maximum IfG and 28.5 HSIY in diesel fael only opeFation

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La compréhension des écoulements de fumées issus d’un foyer d’incendie au sein d’une station souterraine de métropolitain, en présence d’accès passagers et d’une ventilation mécanique forcée,constitue l’objectif principal de ce présent mémoire. Deux maquettes basées sur le nombre de Froude (Fr) et sur le rapport de quantité de mouvement (r) sont mises en place. La première, préexistante,représente une station complète à échelle 1/30e et l’incendie y est simulé par un brûleur air-butane. Cependant, l’analyse y est limitée à une approche globale et le manque d’information sur le développement des écoulements internes est préjudiciable. Une seconde maquette adonc été développée, version simplifiée de la précédente, permettant d’étudier finement (vitesse,température) la confrontation entre un jet chaud vertical et un écoulement froid traversier. Cette approche expérimentale est complétée par des simulations numériques LES permettant d’accéder aux champs 3D. Les études réalisées ont mis en évidence 4 paramètres influents couplés : la différence de hauteur station-tunnel (H/H0), le débit de ventilation, le nombre et la position des accès et le réseau hydraulique du tunnel amont. Quelle que soit la configuration, un débit d’extraction« critique » peut-être mis en place pour contrer la contamination thermique des accès, définissant ainsi un facteur r « critique ». De plus, les écoulements dans les accès et dans la station sont dépendants de leur nombre et de leur position : suivant les configurations, deux ou trois régimes sont obtenus. Enfin, la représentativité du réseau présente une forte influence sur les écoulements internes. / Smoke spreading in an underground subway station is analyzed and studied by taking into account parameters such as passenger accesses and forced ventilation systems. Two sub-scale models are considered to arise such analysis ; based on the Froude number (Fr) or momentum ratio(r). The first experiment based on Froude number conservation is conducted on a 1/30e scale modelof a realistic subway station with fire provided from an air-butane burner. Due to restricted access to local temperature and velocity measurements, a second model was entirely developed during the course of this work ; the main issue is to study momentum ratio and thermal spreading. Numerical studies were in parallel carried out from an house-code LES turbulent model.Four main parameters were thus identified : tunnel/station height ratio (H/H0), ventilation massflowrate, number and position of accesses and hydraulic network in which the subway station islocated. « Critical » flowrate can be imposed in order to avoid thermal speading within the passenger accesses and consequently a critical factor was defined. The air/smoke flow is strongly linked to the number and position of accesses and also of the geometrical configuration. Two or three regimes can be identified. Finally internal flows in the accesses and in the station are also strongly influenced by the pressure drop of the hydraulic network.

beta-Carbolines are tricyclic compounds deriving from the condensation of indoleamines or tryptophan with fairly electrophilic carbonylic compounds to form a fused benzene-pyrrole-pyridine ring system (Pictet-Spengler reaction). Previous investigation carried out with model systems proved the facile formation of various tetrahydro-beta-carboline-3-carboxylic acids (beta-CCA) from tryptophan and reactive carbonyls present in wood smoke, under conditions simulating those of foods during their smoking process. The present work has been undertaken to investigate and confirm the actual occurence of such compounds in real smoked foodstuffs of animal origin. Five representative beta-CCA were selected taking into account the high content of their precursor aldehydes in smoke (formaldehyde, acetaldehyde, glycolaldehyde) and/or the facility of their formation during the model system experiments (benzaldehyde and salicylaldehyde derivatives). They were synthesized following methods based on the Pictet-Spengler reaction as they were described in the literature, or by slightly modifying and altering them. The structure of the synthesised products was confirmed using spot tests, melting points, elemental analysis and spectrometric methods such as fluorescence, UV, 1HNMR, MS and 13CNMR spectroscopy. A method was developed for the isolation of these compounds from smoked solid foods. The samples were extracted with an aqueous acidic medium containing semicarbazide to prevent artifactual formation of beta-CCA. The extract was purified on an XAD-4 resin containing, clean-up column. The eluate was concentrated, further purified by extraction with CHaCla and analysed by high performance liquid chromatography on a Spherisorb ODS1 reversed phase column with gradient elution and fluorescence detection. The quantitation was based on calculating the ratio of the peek area of each compound to the peak area of the internal standard (serotonin creatinine sulphate). The mean recovery of the method was about 76% for the more hydrophilic derivatives of formaldehyde, acetaldehyde and glycol aldehyde and 11% for the more hydrophobic derivatives of benzaldehyde and salicylaldehyde. Higher concentrations of analytes in the samples led to decreased recoveries. The detection limit was lower than 25 mug/kg for the more hydrophilic and 2 mg/kg for the more hydrophobic group of compounds. Thirty four samples of miscellaneous smoked food products such as dry salamis, heat processed comminuted meat products, cured meats (heat processed or not), raw or heat processed fish, hard cheese, were analysed. The beta-CCA concentration in them was variable depending on many factors such as pH value, heavy or light smoking and maturation time. Dry, fermented comminuted meat products contained the higher concentrations. Tetrahydro-beta-carboline-3-carboxylic acid prevailed in all samples examined and was detected at a level of 0.86 up to 22.63 mg/kg in dry salamis, whereas in other samples it ranged from 16 to 680 mug/kg. The levels of 1-methyl- and 1- hydroxymethyl-tetrahydro-beta-carboline-3-carboxylic acids were much lower (0-881 mug/kg and 0-444 mug/kg respectively). The occurence of benzaldehyde and salicylaldehyde derivatives was not definitely proved. The synthesised beta-CCA were tried for mutagenicity using the Ames test. None of them was mutagenic to Salmonella typhimurium TA-100, TA-98, TA-97 strains with and without metabolic activation, end without preincubation. At concentrations higher than 100 mug/plate, 1-hydroxymethyl- and unsubstituted tetrahydro-beta-carboline-3-carboxylic acids were toxic to strains TA-98 and TA-100. B-Carbolines are biologically active compounds and their detection in smoked foods might help to prevent potential implications to the consumers' health.

Orientador: Caio Glauco Sanchez / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-14T13:31:19Z (GMT). No. of bitstreams: 1 Cavani_ClaudiaSantos_M.pdf: 4106954 bytes, checksum: 66d24da856b3915d0d3c8e3129673957 (MD5) Previous issue date: 2008 / Resumo: Os materiais poliméricos vêem sendo empregados em diversas aplicações. A versatilidade de monômeros existentes, além da possibilidade de síntese de copolímeros, formulação de blendas poliméricas e confecção de compósitos e nanocompósitos favorecem a obtenção de um amplo número de materiais, cada qual com propriedades específicas e de interesse para diferentes áreas de aplicação. No entanto, apesar da reconhecida possibilidade de uso, a grande maioria dos polímeros apresenta caráter inflamável e pode facilmente pegar fogo, além de manter a propagação da chama com liberação de gases tóxicos e fumaça. Considerando o crescente uso dos materiais poliméricos, torna-se de interesse das indústrias e da comunidade científica, o estudo das características de inflamabilidade dos mesmos. O objetivo deste trabalho é estudar as características de inflamabilidade dos seguintes materiais: resina de poliéster insaturado do tipo ortoftálica, nanocompósito de resina ortoftálica e argila, poli(cloreto de vinila) rígido (PVC), copolímero de acrilonitrila-butadieno-estireno (ABS), blenda de policarbonato e poli(tereftalato de etileno) (PC/PBT). Foram realizados ensaios de queima vertical, queima horizontal, índice de oxigênio, ponto de fulgor, ponto de auto-ignição, densidade de fumaça e análises termogravimétricas. O nanocompósito de resina ortoftálica e argila apresentou maior tempo de permanência de chama, maior velocidade de queima, maior taxa de densidade de fumaça, menor índice de oxigênio e menor ponto de fulgor, quando comparado à resina pura; e as curvas termogravimétricas não mostraram alterações de estabilidade térmica da resina pela argila. Para os materiais PVC, a adição de retardante de chama e/ou supressor de fumaça resultou em melhor desempenho quanto às características de inflamabilidade; especialmente para o PVC contendo retardante de chama e supressor de fumaça, que mostrou o maior índice de oxigênio e a menor taxa densidade de fumaça. Os materiais ABS e PC/PBT apresentaram comportamento intermediário aos materiais de resina e PVC, nos ensaios de queima vertical e ponto de auto-ignição; e nos testes de ponto de fulgor, índice de oxigênio e taxa de densidade de fumaça mostraram resultados similares aos de resina pura e nanocompósito. / Abstract: The polymer materials are being used in several applications. The great number of existent monomers, as well as the possibility of copolymers synthesis, polymeric alloys formulation and the composites and nanocomposites show that it is possible to obtain materials with different specific properties and for being used in different application areas. However, besides the recognized possibility of application, the majority of polymers show inflammable character and are able to keep fire propagation with the releasing of smoke and toxic gases. Considering that the use of these materials is increasing, the study of their flammability characteristics became important for the industries and the scientific community. The aim of this work is to study the flammability properties of the following materials: unsaturated polyester resin, nanocomposite of unsaturated polyester resin and clay, rigid poly(vinyl chloride) (PVC), copolymer acrylonitrile-butadiene-styrene (ABS), alloy polycarbonate and poly(ethylene terephthalate) (PC/PBT). Vertical burning, horizontal burning, oxygen index, flash ignition point, self-ignition point, density of smoke tests and thermalgravimetric analysis were performed. The clay nanocomposite showed higher flame time, higher burning speed, higher smoke index, lower oxygen index and lower flash ignition point, when compared to neat resin; and the thermal analysis didn't show considerable differences of the thermal stability between neat resin and nanocomposite. For PVC materials, the flame retardant and/or smoke suppressant addition improved the flammability properties of PVC, especially for PVC with flame retardant and smoke suppressant addition, which showed the highest oxygen index and the lowest smoke index. Copolymer ABS and PC/PBT blends showed a behavior between resin and PVC materials for the vertical burning and selfignition point tests; for the flash ignition point, oxygen index and smoke index tests, ABS and PC/PBT showed similar behavior to neat resin and nanocomposites. / Mestrado / Termica e Fluidos / Mestre em Engenharia Mecânica

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Meteorology, 1973. / Microfiche copy available in Archives and Science / Includes bibliographical references. / by John S. Lague. / M.S.