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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
161

Detecção de bactérias redutoras de sulfato em efluente e sedimento de mina de urânio

Sheila Kênia de Almeida 17 August 2005 (has links)
Um dos graves problemas ambientais oriundos da indústria de mineração é a drenagem ácida de mina que ocorre quando a pirita e outros minerais sulfetados são oxidados devido à presença de oxigênio e água, produzindo ácido sulfúrico que solubiliza metais presentes no solo/rocha. Em uma planta das Indústrias Nucleares do Brasil INB, na Unidade de Tratamento de Minérios (UTM) este problema tem se pronunciado de forma preocupante levando a dissolução de espécies radioativas e metálicas presentes. O tratamento da água ácida usando bactérias redutoras de sulfato, proporciona decréscimo da acidez que é decorrente da redução do sulfato a sulfito e precipitação dos metais como sulfetos. Nesse contexto, o presente estudo foi realizado visando a caracterizar sazonalmente e espacialmente populações de bactérias redutoras de sulfato (BRS) nos efluentes líquidos e amostras de sedimento da cava da mina (CM) e nos bota-foras 4 e 8 (BF4 e BF8) coletadas na UTM. Tais informações poderão permitir posteriormente, estudar mecanismos de biomanipulação a fim de remediar situações impactantes. Menores valores de pH , abaixo de 3,5, foram medidos no período de março a abril em amostras de água da cava da mina e a maior população de BRS (2,8 NMP. mL-1) foi observada em fevereiro em amostras do BF8. Os valores encontrados para matéria orgânica na água foram menores do que aqueles encontrados no sedimento. A concentração de oxigênio dissolvido na água variou de 0,65 g/L a 13,3 g/L. As amostras de sedimento apresentaram maiores valores de BRS (10,2 NMP/mL), quando comparadas com amostras de água (0,63 NMP/mL). Tais resultados eram esperados uma vez que, nas amostras de água coletadas próximas ao sedimento foram observadas menores concentrações de oxigênio dissolvido (7,10g/L) e maiores concentrações de matéria orgânica disponível (17,0 mg/L) quando os resultados foram comparados com aqueles obtidos para amostras de água coletadas na superfície (0,004mg/L). Os resultados mostram, portanto, que o efluente ácido gerado apresenta altos teores de metais estáveis e radioativos, sulfato, baixo pH e presença de bactérias redutoras de sulfato. / One of the most serious environmental problems created by the mining industry is acid mine drainage. In one plant of Nuclear Industries of Brazil - INB, this problem is a matter of concern. The presence of iron sulfites, such as pyrite, generates water with acidity above the levels allowed by the legislation and therefore, inappropriate for releasing straight into the environment. The industry maintain a high cost treatment in acid water from mines and waste disposal which consists in neutralizing and precipitating heavy metals. The treatment of acid water using SRB (sulfate-reducing bacteria) has been used in other countries with quite good technical results as well as economical advantages and thus, the object of this research. The use Sulfate Reducing Bacteria takes to a decreasing of the acidity by reducing sulfate to sulfite and precipitating the stable metals as sulfides. A seasonal study was carried out on the sulfate-reducing bacteria present in the liquid effluent discharged from two wastes disposal of the uranium mine, in phase of decommission, in Caldas/MG. This study shows the presence of SRB in the analyzed environmental, as well as some factors that are related with the amount of SRB presents, such as: dissolved oxygen, pH and organic matter. SRB was presented in water samples with high concentrations of heavy metals and low pH values, as well as in samples with high oxygen levels. The sediment samples were the preferential place for SRB occurrence and site BF8 presented the highest values of SRB.
162

Isolation, characterization and exploitation of soil micro-organisms for bioremediation of benzo(a)pyrene contamination.

January 2005 (has links)
by Ho, Kai-Man. / Thesis submitted in: December 2004. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 158-179). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstracts --- p.ii / Contents --- p.vii / List of figures --- p.xiv / List of tables --- p.xvii / Abbreviations --- p.xx / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Poly cyclic Aromatic Hydrocarbons (PAHs) / Chapter 1.1.1 --- Characteristics of PAHs --- p.1 / Chapter 1.1.2 --- Sources of PAHs --- p.3 / Chapter 1.1.3 --- Environmental fates of PAHs --- p.5 / Chapter 1.1.4 --- Effects of PAHs on living organisms --- p.7 / Chapter 1.1.5 --- Summary --- p.10 / Chapter 1.2 --- Target PAH: Benzo[a]pyrene (BaP) --- p.10 / Chapter 1.3 --- PAH contamination in Hong Kong --- p.14 / Chapter 1.4 --- Remediation for PAHs contaminated soils --- p.15 / Chapter 1.4.1 --- Chemical/ Physical methods --- p.15 / Chapter 1.4.2 --- Bioremediation --- p.16 / Chapter 1.5 --- Biodegradation of PAHs by bacteria and fungi --- p.18 / Chapter 1.5.1 --- Tolerance and degradation --- p.18 / Chapter 1.5.2 --- Biodegradation of PAHs by microorganisms --- p.20 / Chapter 1.5.2.1 --- Bacteria --- p.22 / Chapter 1.5.2.2 --- Fungi --- p.23 / Chapter 1.6 --- Environmental standards --- p.26 / Chapter 1.7 --- Strategies of soil sampling and microbial isolation --- p.26 / Chapter 1.7.1 --- Contaminated soil vs. uncontaminated soil --- p.26 / Chapter 1.7.2 --- Native species vs. foreign species --- p.29 / Chapter 1.7.3 --- Background of the sampling areas --- p.30 / Chapter 1.7.3.1 --- North Tsing Yi shipyard --- p.30 / Chapter 1.7.3.2 --- "Tsam Chuk Wan, Sai Kung" --- p.33 / Chapter 1.8 --- Objectives of this study --- p.33 / Chapter 2. --- Materials and Methods --- p.35 / Chapter 2.1 --- Soil Collection --- p.35 / Chapter 2.1.1 --- Abandoned shipyard soil and its sediment soil --- p.35 / Chapter 2.1.2 --- "Tsam Chuk Wan, Sai Kung" --- p.35 / Chapter 2.2 --- Characterization of soils --- p.35 / Chapter 2.2.1 --- Sample preparation --- p.36 / Chapter 2.2.2 --- Soil pH --- p.36 / Chapter 2.2.3 --- Electrical conductivity --- p.36 / Chapter 2.2.4 --- Salinity --- p.36 / Chapter 2.2.5 --- Total organic carbon contents --- p.38 / Chapter 2.2.6 --- Metal analys --- p.is / Chapter 2.2.7. --- Oil and grease content --- p.38 / Chapter 2.2.8 --- Soil texture --- p.39 / Chapter 2.2.9 --- Available ammoniacal nitrogen and oxidized nitrogen --- p.39 / Chapter 2.2.10 --- Available Phosporus --- p.40 / Chapter 2.2.11 --- Total Nitrogen and total Phosporus --- p.40 / Chapter 2.2.12 --- Moisture / Chapter 2.2.13 --- DTPA-extractable metals --- p.41 / Chapter 2.2.14 --- Extraction of PAHs and organic pollutants --- p.41 / Chapter 2.2.14.1 --- Extraction procedures --- p.41 / Chapter 2.2.14.2 --- GC-MSD conditions --- p.41 / Chapter 2.2.14.3 --- Extraction efficiency --- p.43 / Chapter 2.2.15 --- Soil colour --- p.43 / Chapter 2.3 --- Screening and selection of microorganismms --- p.43 / Chapter 2.3.1 --- Isolation of potential BaP-degrading microorganisms --- p.44 / Chapter 2.3.1.1 --- Isolation of bacteria --- p.44 / Chapter 2.3.1.2 --- Isolation of fungi --- p.44 / Chapter 2.3.2 --- Cultures preserving microorganisms --- p.46 / Chapter 2.3.3 --- Screening and selection of microbes --- p.46 / Chapter 2.3.3.1 --- Bacteria --- p.46 / Chapter 2.3.3.2 --- Fungi --- p.46 / Chapter 2.3.4 --- Survival test --- p.47 / Chapter 2.3.5 --- Removal efficiency (RE) towards BaP by the microorganisms --- p.47 / Chapter 2.3.5.1 --- Bacteria --- p.47 / Chapter 2.3.5.2 --- Fungi --- p.48 / Chapter 2.3.6 --- Removal efficiency (RE) --- p.48 / Chapter 2.3.7 --- Relationship of absorbance of bacterial culture and bacterial biomass --- p.49 / Chapter 2.4 --- Identification of selected microorganisms --- p.49 / Chapter 2.4.1 --- Identification of bacterium --- p.49 / Chapter 2.4.1.1 --- 16S rDNA sequencing --- p.49 / Chapter 2.4.1.1.1 --- Primers --- p.49 / Chapter 2.4.1.1.2 --- DNA extraction --- p.51 / Chapter 2.4.1.1.3 --- Specific PCR --- p.51 / Chapter 2.4.1.1.4 --- Gel electrophoresis --- p.51 / Chapter 2.4.1.1.5 --- Purification of PCR products --- p.52 / Chapter 2.4.1.1.6 --- DNA sequencing --- p.52 / Chapter 2.4.1.2 --- Midi Sherlock® Microbial Identification System (MIDI) --- p.53 / Chapter 2.4.1.3 --- Biolog MicroLog´ёØ system (Biolog) --- p.55 / Chapter 2.4.2 --- Identification of fungi --- p.56 / Chapter 2.4.2.1 --- ITS DNA sequencing --- p.56 / Chapter 2.4.2.2 --- Observation under electronic microscope --- p.58 / Chapter 2.5 --- Growth curve of the microorganism --- p.58 / Chapter 2.5.1 --- Bacterium --- p.58 / Chapter 2.5.2 --- Fungi --- p.58 / Chapter 2.6 --- Preparation of Benzo[a]pyrene (BaP) stock solution --- p.58 / Chapter 2.7 --- Comparison of isolated bacterium and fungi --- p.60 / Chapter 2.8 --- Optimization of BaP degradation by selected fungus --- p.60 / Chapter 2.8.1 --- Preparation of straw compost inoculated with selected fungus --- p.60 / Chapter 2.8.2 --- Effect of incubation time --- p.61 / Chapter 2.8.3 --- Effect of initial BaP concentration --- p.61 / Chapter 2.8.4 --- Effect of inoculum size / Chapter 2.8.5 --- Effect of temperature --- p.61 / Chapter 2.8.6 --- Effect of soil pH --- p.62 / Chapter 2.8.7 --- Study of BaP degradation pathway by the microorganisms using GC-MSD --- p.62 / Chapter 2.9 --- Chitin Assay --- p.62 / Chapter 2.10 --- Enzyme assay --- p.63 / Chapter 2.10.1 --- Laccase assay --- p.63 / Chapter 2.10.2 --- Manganese peroxidase assay --- p.63 / Chapter 2.10.3 --- Lignin peroxidase assay --- p.64 / Chapter 2.11 --- Toxicity of treated soil --- p.64 / Chapter 2.12 --- Statistical analysis --- p.65 / Chapter 3. --- Results --- p.66 / Chapter 3.1 --- Soil Collection --- p.66 / Chapter 3.1.1 --- North Tsing Yi shipyard --- p.66 / Chapter 3.1.2 --- "Tsam Chuk Wan, Sai Kung" --- p.66 / Chapter 3.2 --- Characterization of soil samples --- p.71 / Chapter 3.3 --- Extraction efficiency of Benzo[a]pyrene --- p.79 / Chapter 3.4 --- Screening and selection of microorganisms --- p.79 / Chapter 3.4.1 --- Isolation ofpotential BaP-degrading microorganisms --- p.79 / Chapter 3.4.2 --- Screening and selection of microbes --- p.87 / Chapter 3.4.2.1 --- Bacteria --- p.87 / Chapter 3.4.2.2 --- Fungi --- p.93 / Chapter 3.4.3 --- Growth curve of the microorganisms --- p.95 / Chapter 3.4.3.1 --- Bacterium --- p.95 / Chapter 3.4.3.2 --- Fungi --- p.99 / Chapter 3.5 --- Comparison of isolated bacterium and fungi --- p.99 / Chapter 3.6 --- Identification of selected microorganisms --- p.102 / Chapter 3.6.1 --- Identification of bacterium --- p.103 / Chapter 3.6.1.1 --- 16S rDNA sequencing --- p.103 / Chapter 3.6.1.2 --- Midi Sherlock® Microbial Identification System (MIDI) --- p.103 / Chapter 3.6.1.3 --- Biolog MicroLog´ёØ system (Biolog) --- p.107 / Chapter 3.6.2 --- Identification of fungi --- p.107 / Chapter 3.6.2.1 --- ITS DNA sequencing --- p.107 / Chapter 3.6.2.2 --- Observation under electronic microscope --- p.113 / Chapter 3.7 --- Optimization of BaP degradation by the selected fungus: Trichoderma asperellum --- p.107 / Chapter 3.7.1 --- Effect of incubation time --- p.107 / Chapter 3.7.2 --- Effect of inoculum size --- p.113 / Chapter 3.7.3 --- Effect of initial BaP concentration --- p.113 / Chapter 3.7.4 --- Effect of soil pH --- p.113 / Chapter 3.7.5 --- Effect of temperature --- p.117 / Chapter 3.8 --- Determination of breakdown products of BaP by BaP-degrading microorganisms --- p.117 / Chapter 3.9 --- Enzyme assay --- p.117 / Chapter 3.10 --- Evaluation of toxicity by using indigenous bacteria --- p.121 / Chapter 4. --- Discussion --- p.128 / Chapter 4.1 --- Physico-chemical properties of soil samples --- p.128 / Chapter 4.2 --- Determination of BaP and other organic compounds --- p.131 / Chapter 4.3 --- Identification of the microorganisms --- p.132 / Chapter 4.3.1 --- Bacteria --- p.132 / Chapter 4.3.2 --- Fungi --- p.134 / Chapter 4.4 --- Biodegradation by BaP-degrading microorganisms --- p.135 / Chapter 4.4.1 --- Isolation and screening of BaP-degrading microorganisms --- p.135 / Chapter 4.4.2 --- Biodegradation of BaP --- p.137 / Chapter 4.4.2.1 --- Bacteria --- p.137 / Chapter 4.4.2.2 --- Fungi --- p.138 / Chapter 4.4.3 --- BaP degradation pathway --- p.140 / Chapter 4.4.3.1 --- Bacteria --- p.140 / Chapter 4.4.3.2 --- Fungi --- p.140 / Chapter 4.5 --- Optimization of PAH degradation by T. asperellum --- p.143 / Chapter 4.5.1 --- Effect of incubation time --- p.143 / Chapter 4.5.2 --- Effect of initial BaP concentration --- p.144 / Chapter 4.5.3 --- Effect of inoculum size fungus --- p.144 / Chapter 4.5.4 --- Effect of soil pH --- p.145 / Chapter 4.5.5 --- Effect of temperature --- p.146 / Chapter 4.6 --- Comparison the selected bacterium and fungi --- p.146 / Chapter 4.7 --- Evaluation of toxicity by using in indigenous bacteria --- p.148 / Chapter 4.8 --- Post treatment by crude enzyme of Pleurotus pulmonarius --- p.149 / Chapter 4.9 --- Limiting factors for BaP degradation --- p.150 / Chapter 4.10 --- Further Investigations --- p.152 / Chapter 5. --- Conclusion --- p.155 / Chapter 6. --- References --- p.158
163

Multifunctional photocatalytic substrates and textiles constructed via Layer-by-Layer self-assembly of Ag and TiO2 nanoparticles / Substrats et textiles multifonctionnels construits par assemblage couche-par-couche de nanoparticules d’Ag et TiO2

Motay, Marvin 03 July 2018 (has links)
Des films multicouches à base de nanoparticules de TiO2 et d’Ag ont été construits sur des substrats modèles et des textiles via la technique du Layer-by-Layer (LbL). Les films à base de nanoparticules de TiO2 construits sur substrats modèles ont montré un comportement photocatalytique non conventionnel pour la minéralisation de l’acide formique en phase gaz sous irradiation UV-A, et une minéralisation très importante a été obtenue avec un film possédant une unique couche de nanoparticule de TiO2. Ces films ont également montré des propriétés biocides sous irradiation UV-A. La mise en œuvre d’une méthode one-pot, combinant la synthèse photo-induite des nanoparticules d’Ag et dépôt de la couche de TiO2 par LbL, a permis la synthèse de nanoparticules d’Ag directement au sein des films et une exaltation très importante des propriétés photocatalytiques des films. Les méthodes de constructions ont été transférées avec succès sur textiles. Les films restent photocatalytiquement actifs et biocides sous irradiation UV-A après plusieurs cycles de lavages. / TiO2 and Ag nanoparticle multilayered films were constructed on model substrates and textiles via Layer-by-Layer (LbL) assembly. The TiO2 nanoparticle based films constructed on model substrates showed a non-conventional photocatalytic behaviour for gas phase formic acid mineralisation upon UV-A irradiation, and a high mineralisation was obtained for a single layer TiO2 nanoparticle film. These films also showed biocidal properties upon UV-A irradiation. The elaboration of a one-pot method, combining the photo-induced synthesis of Ag nanoparticles and the LbL deposition of TiO2 nanoparticle layer, allowed the direct synthesis of Ag nanoparticles within the films and a high enhancement of the film photocatalytic properties. The construction methods were successfully transfered on textile surfaces. The films were photocatalytically active and biocidal under UV-A irradiation after several washing treatment cycles.
164

Mode d'action biocide de nouveaux procédés de décontamination sur deux formes de résistances bactériennes / Foam biocidal mechanisms for biological decontamination of two bacterial resistances : spores and biofilms

Le Toquin, Esther 16 November 2018 (has links)
Il existe de nombreuses technologies de décontamination, néanmoins les spores et les biofilms bactériens demeurent une préoccupation majeure dans de nombreux domaines, tels que le secteur hospitalier, alimentaire et de la biodéfense car elles sont résistantes. Une mousse novatrice contenant un biocide (l’hypochlorite de sodium ou le peroxyde d’hydrogène) et un agent stabilisant (le Xanthane) a été étudiée pour répondre à ce besoin. Cette mousse a la capacité d’être mise en oeuvre de différentes façons sur le terrain par : pulvérisation au sol ; talochage et pulvérisation sur les murs ; remplissage de pièces entières (murs et sols). Le travail de thèse est d’évaluer les modes d’action biocide de ces mousses sur les spores et les biofilms. Afin d’étudier le mode d’action de ces mousses des protocoles expérimentaux ont été mis au point sur les spores et les biofilms suivant leurs futures mises en oeuvre (horizontale, verticale et remplissage) et suivant différents facteurs environnementaux pouvant influencer leur efficacité de décontamination (températures, salissures, matériaux, …). L’ensemble de ce travail de thèse a permis de distinguer l’intérêt de la mousse au Xanthane contenant NaOCl 5% par rapport à celle H2O2 12% pour répondre aux besoins spécifiques de la décontamination des agents de la menace biologique. Cette mousse permet une décontamination rapide de 7 logs de spores en 30 minutes pour chacune des trois voies de mise en oeuvre à 20°C. De plus, elle permet la destruction de biofilms contenant 107 de bactéries/cm² en 1 heure maximum sur un support horizontal et par remplissage. Cette mousse NaOCl est suffisamment mature pour pouvoir réaliser un futur transfert industriel. / Several decontamination technologies exist, however bacterial spores and biofilms remain a concern in a lot of fields, like hospital, alimentary and military. A new foam containing a biocide (sodium hypochlorite or hydrogen peroxide) and a stabilizing agent (Xanthan) has been studied to answer this problematic. This foam can be used in different ways on the field following contaminations: grounds’ spraying, walls’ covering and spraying, full pieces’ filling (walls and ground). The goal of this thesis is to evaluate the biocide efficiency of these foams on spores and biofilms. We optimized experimental protocols in order to study mechanisms of foams’ action on spores and biofilms based on theirs future applications (horizontal, vertical and filling) and depending on different environmental factors which may impact foam decontamination efficiencies (materials, temperatures, soil, …). This thesis work enabled to highlight the Xanthan foam containing 5% NaOCl from the one including 12% H2O2 in military sector. This foam allows a rapid decontamination, about 7 logs of spores in 30 minutes, for each of the three ways of use at 20°C. Moreover, the destruction of biofilms containing 107 logs of bacteria/cm² was achieved in 1 hour on a horizontal support by filling. This NaOCl foam is ready to be used for industrials.
165

Avaliação da microbiota fúngica e presença de micotoxinas em amostras de plantas medicinais irradiadas, adquiridas no comércio varejista e atacadista / Evaluation of fungal bioburden and micotoxins presence in irradiated samples of medicinal plants purchased from wholesale and retail market

Simone Aquino 13 November 2007 (has links)
O presente estudo analisou os efeitos da radiação gama na sobrevivência de fungos em plantas medicinais embaladas, adquiridas do comércio atacadista e varejista, em diferentes períodos (0 e 30 dias) após o tratamento por irradiação. Cinco tipos de plantas medicinais [Peumus boldus, Cameilia sinensis, Maytenus ilicifolia, Pauilinia cupana and Cássia angustifolia), foram coletadas de diferentes municípios do Estado de São Paulo e submetidas ao tratamento por irradiação, utilizando-se uma fonte 60Co (tipo Gammacell 220), com doses de 5,0 kGy e 10 kGy e taxa de dose de 3,0 kGy/h. Amostras não irradiadas (grupo controle) foram usadas na contagem de fungos e diluições seriadas de 10-1 a 10-6 das amostras foram semeadas em duplicata e plaqueadas usando o método de cultura em superfície, em ágar Dicloran Glicerol 18% (DG18) e contadas após cinco dias a 25°C. O grupo controle revelou a presença dos gêneros Aspergilius e Penicillium, os quais são conhecidos como fungos toxigênicos e poucas amostras do grupo controle estavam dentro dos limites seguros, estabelecidos pela Organização Mundial de Saúde (OMS, 1998) para plantas medicinais. Em resposta a resistência do tratamento por ionização, na dose de 5 kGy, foi obsen/ado que os gêneros Aspergilius, Piioma e Syncephalastrum foram radiorresistentes, após o processo (dia 0 e 30° dia). O tratamento por radiação gama foi efetivo na descontaminação de todas as amostras de plantas medicinais, após 30 dias, com a dose de 10 kGy e mantidas em condições de vedação. Não foram detectadas aflatoxinas nas amostras do grupo controle, ainda que estas amostras estivessem intensamente contaminadas com Aspergilius flavus. / This present study evaluated the effect of gamma radiation on the fungal survival in packed medicinal plants, purchased from wholesale and retail market, in different period (0 and 30 days) after the treatment. Five kind of medicinal plants (Peurnus boldus, Camellia sinensis, Maytenus ilicifolia, Pauilinia cupana and Cassia angustifolia), were collected from different cities of São Paulo State, and submitted to irradiation treatment using a 60Co source (type Gammacell 220) with doses of 5,0 kGy and 10 kGy and at dose rate of 3.0 kGy/h. Non-irradiated samples (control group) were used for fungal counts and serial dilutions from 10-1 to 10-6 of the samples were seeded in duplicates and plated using the surface culture method in Dichloran 18% Glycerol Agar (DG 18) and were counted after five days at 25°C. The control group revealed the presence of genera Aspergillus and Penicillium, which are known as toxigenic fungi and a few samples of control group were within the safety limits of World Health Organization (WHO, 1998) to medicinal plants. In response to resistance of ionizing treatment, in the dose of 5 kGy, it was obsen/ed that the genera Aspergillus, Phoma and Syncephalastrum were radio-resistant after the process (day 0 and 30° day). The treatment by gamma radiation was effective in decontamination of all irradiated samples of medicinal plants, after 30 days, with the dose of 10 kGy and kept of veiled conditions. It was not detected aflatoxins in samples of control group, even though these samples were heavily contaminated with Aspergillus flavus.
166

Avaliação da contaminação microbiológica de drogas vegetais e potencial descontaminação por plasma / Evaluation of microbiologic contamination of vegetable drugs and decontamination potential by plasma

Siliane Bertoni Kalkaslief de Souza 24 August 2007 (has links)
A qualidade, eficácia e segurança no emprego de drogas vegetais dependem, entre outras questões, de sua qualidade sanitária. Sua origem e manuseio, em condições no geral inadequadas, propiciam biocarga elevada e abrangente, o que implica riscos para saúde. O presente trabalho objetivou conhecimento da microbiota das plantas estudadas e o desenvolvimento de estudos de sua descontaminação por plasma, tendo-se analisado os parâmetros físicos que influenciaram este processo. O projeto possibilitou a descontaminação de drogas vegetais com alta carga microbiana. Estudou-se a alcachofra (Cynara scolymus L.), camomila (Chamomilla recutita (L.) Rauschert.), ginco (Ginkgo biloba L.) e guaraná (Paullinia cupana Kunth), adotando parâmetros de processo que alegadamente permitem a integridade dos princípios ativos termossensíveis. Para isso, foi empregado reator disponível no Laboratório de Sistemas Integráveis, pertecente à Escola Politécnica da Universidade de São Paulo, em sistema com acoplamento capacitivo modo RIE (Reactive Ion Etching). Neste sistema, trabalhou-se com oxigênio adicionado de peróxido de hidrogênio. Todos os processos de descontaminação foram desenvolvidos a temperatura ambiente, sob diferentes parâmetros físicos complementares. A eficácia do processo foi investigada, empregando-se contagem de microrganismos heterotróficos, assim como pesquisa de indicadores de patogênicos (Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella spp, Escherichia coli). As avaliações microbiológicas, quantitativas e qualitativas, assim como os estudos decorrentes dos dados obtidos, foram desenvolvidos no Laboratório de Controle Biológico da Faculdade de Ciências Farmacêuticas - USP. Os resultados obtidos após a descontaminação por plasma de oxigênio (100%), a potência de 150 W, evidenciaram redução de até 4 ciclos de aeróbicos totais. No processo por plasma peróxido de hidrogênio (20%) e oxigênio (80%), a uma potência de 150 W, observou-se a redução de até 4 ciclos log de aeróbios totais para as drogas vegetais deste estudo. A presença de substâncias químicas complexas da camomila, que contêm óleo volátil, flavonóides, aminoácidos, ácidos graxos, sais minerais, cumarinas, mucilagens e ácidos orgânicos, interferem no processo por plasma provavelmente em decorrência de a mucilagem formar um filme protetor, impedindo a difusão gasosa em ambos os processos por plasma. Assim, não só a camomila mas também o guaraná, com biocargas iniciais respectivamente de 6,6x106 UFC/g e 2,7x106 UFC/g, mantiveram-se com níveis de contaminação da mesma ordem de grandeza, após os desafios com plasma. A contagem bacteriana da alcachofra (fornecedor B), que foi submetida ao processo de descontaminação através do plasma O2 (100%), (potência de 150 W, pressão de 100 mTorr e vazão de 200 sccm), sofreu redução de dez vezes, independentemente do tempo do processo. Possivelmente este resultado, que aparenta inconsistência, decorre da ação apenas superficial do plasma. A descontaminação por processo de plasma de oxigênio e de peróxido de hidrogênio para a alcachofra (fornecedor B) não foi eficaz, devido à predominância de elementos lignificados. As amostras de alcachofra (fornecedor C), com baixa percentagem de vasos de xilema lignificados e fibras lignificadas evidenciaram a maior eficácia do processo por plasma, pois possibilitou grande difusão gasosa sobre as amostras. O estudo permitiu ainda concluir que à aplicabilidade do plasma na descontaminação de drogas vegetais depende da resistência dos microrganismos, mas igualmente das características da planta, sejam aquelas de natureza morfoanatômica, enzimática ou química. Estudos específicos devem ser desenvolvidos para cada situação. / The quality, effectiveness and safety of vegetal drugs usage depend, among others issues, on their sanitary quality. Their origin and handling, usually under inadequate conditions, propitiate high bioburden, what presents risks to health. This project aimed at the evaluation of the microbiota of the plants studied and the development of studies concerning their decontamination by plasma, after the analysis of the physical parameters that influence this process. This project made the vegetal drugs decontamination with high microbiana load possible. Artichoke (Cynara scolymus L.), chamomile (Chamomilla recufifa (L.) Rauschert), ginco (Ginkgo biloba L.) and guaraná (Paullinia cupana Kunth) were studied through parameters that allowed the integrity of thermal sensible active principies. The achievement of our purpose depended on the use of a reactor with RIE (Reactive Ion Etching) capacitive coupled systems, available in the Laboratory of Integrating Systems from Escola Politécnica, University of São Paulo. In this system we worked whith oxygen, whith hydrogen peroxide addition. All decontamination processes were developed at room temperature, under different complementary physical parameters. The process effectiveness was investigated using counting of heterotropic microorganisms, aswell as pathogenic register research (Sfaphylococcus aureus, Pseudomonas aeruginosa, Salmonella spp, Escherichia coll). The microbiological, quantitative and qualitative evaluations, as well as the studies of the data obtained were developed in the Laboratory of Biological Control of Pharmaceutical Sciences Faculty - USP. The results obtained after decontamination by plasma , oxygen (100%) at 150 W potency, evidenced reduction of up to 4 cycles of total aerobics. In the process by plasma hydrogen peroxide (20%) and oxygen (80%) at 150 W potency, a reduction of up to 4 cycles of total aerobics was observed in vegetal drugs. The presence of chamomile chemical complex substances, which contain volatile oil, flavonoids, aminoacids, fatty acids, mineral salts, coumarins, mucilages and organic acids, interfere in the process by plasma, probably due to the fact that the muclilage forms a protective film, preventing the gaseous diffusion in both processes by plasma. Thus no only chamomile but also guaraná, whith initial bioburden of respectively 6,6x106 UFC/g and 2,7x106 UFC/g, kept similar contamination levels after the challenges whith plasma. The bacterial count of artichoke (supolier B), which was sumitted to decontamination process by plasma 02 (100%), (150 W potency, 100mTorr pressure and 200sccm) was reduced ten times, independently of the time of process. This apparently inconsistent result is possibly a consequence of a superficid plasma action. The decontamination by Oxygen and Hydrogen Peroxide plasma process for artichoke (supplier B) was not efficient due to the predominance of lignitic elements. The samples of artichoke from supplier C, whith low percentage of liginitic xylem vessels and fibres evidenced higer efficacy of the process by plasma, what eased great gaseous diffusion over thesamples of artichoke leaves (supplier C). Thus the study of plasma aplicability in vegetal drug decontamination depends not only of microorganisms resistence but also of the plant characteristics, either the morphopanatomic, enzymatic, or chemical ones. A specific study must then be developed for each situation.
167

Entrapment of mobile radioactive elements with coordination polymers and supported nanoparticles / Non traduit

Massasso, Giovanni 13 October 2014 (has links)
La production d'énergie nucléaire nécessite des systèmes avancés pour améliorer les procédures de stockage et de confinement des déchets radioactifs. Par ailleurs, la capture d'éléments radioactifs mobiles dans les effluents des centrales nucléaires demande une amélioration de la capacité et de la sélectivité. L'iode 129-I est un des produits les plus critiques à confiner et il est produit pendant les procédés de recyclage des déchets nucléaires. Dans ce travail de thèse, la classe de matériaux moléculaires, dénommée structures de type Hofmann, a été étudiée en tant que matériaux massifs et nanoparticules supportées pour la capture sélective de l'iode moléculaire. En premier lieu, les matériaux M'(L)[M''(CN)4] ont été précipités sous la forme de poudres microcristallines. L'insertion d'iode dans le réseau des matériaux massifs a été effectuée par différents protocoles: 1) adsorption d'iode dans des solutions de cyclohexane à température ambiante; 2) adsorption d'iode en phase gazeuse à 80 °C; 3) adsorption de vapeurs d'iode en phase gazeuse à 80 °C et en présence de vapeurs d'eau. Les différents protocoles pour l'insertion d'iode n'ont pas influencé la nature de l'iode confiné. Pour la capture en solution, les structures NiII(pz)[NiII(CN)4], NiII(pz)[PdII(CN)4] et CoII(pz)[NiII(CN)4] ont montré une capacité d'une molécule d'iode par unité de maille. L'iode confiné est physisorbé en tant qu'iode moléculaire en interaction avec le réseau. Les modélisations GCMC ont confirmé la capacité maximale et ils ont indiqué que l'iode interagit avec la pyrazine et avec les cyanures. Sur la base des données expérimentales, la modulation des métaux dans le réseau a montré une légère différence dans la force d'interaction entre l'iode et le réseau et une adaptation de la maille spécifique pour chaque composition. Une complète régénération du réseau a été possible, puisque l'iode était complètement désorbé avant la décomposition du réseau. Pour le réseau NiII(pz)[PtII(CN)4], on a observé un mécanisme différent de capture puisque ce réseau contenant Pt a réagi avec l'iode en donnant le complexe de coordination NiII(pz)[PtII/IV(CN)4].I-. La formation de ce type de complexe était déjà observée dans la littérature par Ohtani et al. lesquels avaient préparé le complexe via une synthèse in-situ. Ensuite, le changement du ligand organique pyrazine avec d'autres ligands plus longs, c'est-à-dire la 4,4'-bipyridine (bpy) ou 4,4'-azopyridine (azpy), pour avoir des cages plus grandes a montré une diminution de la capacité maximale de capture d'iode. Les données expérimentales ont suggéré que pour un confinement d'iode optimisé, le réseau doit disposer de cages avec une dimension très proche de la molécule d'iode (0.5 nm). Après l'étude des matériaux massifs, nous avons considéré la préparation de nanoparticules supportées de NiII(pz)[NiII(CN)4] pour la capture d'iode. Nous avons obtenu les nanoparticules via un procédé étape par étape, par imprégnation d'une série de silices mésoporeuses greffées avec un ligand diamine, puis avec les précurseurs de NiII(pz)[NiII(CN)4]. Nous avons utilisé en tant que supports, une silice SBA-15 modifiée et des billes de verre poreux pour obtenir respectivement les nanocomposites Sil@NP and Glass@NP. Par microscopie électronique à transmission, nous avons détecté pour Sil@NP des nanoparticules de diamètre moyen 2.8 nm. L'adsorption d'iode dans les nanoparticules a été confirmée par spectroscopie FT-IR. Les traitements thermiques ont indiqué que la portion d'iode dans les nanoparticules pouvait être désorbé dans l'intervalle 150-250 °C. Nous avons pu estimer que la capacité de capture des nanoparticles était très proche de la capacité du massif NiII(pz)[NiII(CN)4]@I2. / Nuclear power industry still demands further research to improve the methods for the storage and the confinement of the hazardous radioactive wastes coming from the fission of radionuclide 235U. The volatile radioactive 129I (half-life time 15x107 years) is one of the most critical products coming from the reprocessing plants in the fuel-closed cycles. In the present thesis the family of coordination solid networks, known as Hofmann-type structures, was studied in the form as both bulk and supported nanoparticles for the selective entrapment of the molecular iodine. This set of investigated materials exhibited a general formula M'(L)[M''(CN)4] where M' = NiII or CoII; L = pyrazine, 4,4'-bipyridine, 4,4'-azopyridine; M'' = NiII, PdII or PtII. Initially, the material NiII(pz)[NiII(CN)4] and its analogue structures were precipitated as microcrystalline bulky compounds and fully characterized. The insertion of the iodine in the bulky host structures was performed with different methods: 1) adsorption of iodine in solutions of cyclohexane at room temperature; 2) adsorption of iodine vapours at 80 °C; 3) adsorption of iodine vapours at 80 °C in presence of water steam (for few selected materials). The different methods did not affect the nature of the confined iodine. For the entrapment in solution, results indicated that the Hofmann-type structures NiII(pz)[NiII(CN)4], NiII(pz)[PdII(CN)4] and CoII(pz)[NiII(CN)4] could host one I2 molecule per unit cell. The iodine resulted physisorbed as molecular iodine in interaction with the host structure. GCMC simulations confirmed the maximal capacities and indicated that iodine could interact with both the pyrazine and the coordinated cyanides. Experimentally, however, the modulation of the metals showed a slightly different strength of interaction I2-lattice bringing to a different lattice adaptation. The materials also could be fully regenerated since the complete desorption of iodine occurred before the decomposition of the host structure. Reiterated adsorption-desorption steps (3 cycles) on the networks NiII(pz)[NiII(CN)4] and NiII(pz)[PdII(CN)4] indicated an excellent structural resistance to cycling and a maintained high capacity. A different mechanism of confinement was detected for the structure NiII(pz)[PtII(CN)4] which reacted with iodine giving complex NiII(pz)[PtII/IV(CN)4].I-. Finally, the modulation of the organic ligand L indicated that the replacement of the ligand pyrazine with longer ligands, to obtain larger pores, had a detrimental effect on the maximal iodine loading due to a weaker confinement. After the study of the bulk materials, we considered the preparation of supported nanoparticles of NiII(pz)[NiII(CN)4] for the entrapment of iodine. The nanoparticles were obtained by a step-by-step method, impregnating a set of diammine-grafted mesoporous silicas with the precursors of NiII(pz)[NiII(CN)4]. We detected nanoparticles with mean size 2.8 nm by transmission electronic microscopy. The insertion of iodine in the nanoparticles was confirmed by FT-IR. Thermal treatments indicated that the portion of iodine inside the nanoparticles could be reversibly desorbed in the range 150-250 °C and reintroduced in a cyclic process. It was estimated that the amount of physisorbed iodine in the NPs, with respect to the amount of deposited NPs matched with the maximal capacity NiII(pz)[NiII(CN)4]@I2.
168

Synthèse des matériaux nanoporeux pour la décontamination moléculaire et le stockage d'énergie / Synthesis of nanoporous materials for molecular decontamination and energy storage

Kabalan, Ihab 05 January 2016 (has links)
Les composés organiques volatiles (COVs) sont les polluants organiques atmosphériques les plus abondants. Parmi les différentes solutions pour combattre cette pollution, l'utilisation d'adsorbants moléculaires tels que les zéolithes semble être efficace. Cependant les synthèses classiques de zéolithes aboutissent généralement à des tailles de cristaux de l'ordre de plusieurs dizaines de micromètres. Les capacités et les cinétiques de piégeage, sensibles aux phénomènes de diffusion et de surface pourraient potentiellement être améliorées par l'utilisation de nanocristaux ou de produits zéolithiques hiérarchisés (micro/mésoporeux). Dans ce travail de thèse, nous avons synthétisé des zéolithes aluminosiliciques ou purement siliciques de type structural FAU, MFI et *BEA. Ces dernières sont synthétisées avec différentes morphologies et tailles de particules telles que les nanocristaux et les zéolithes hiérarchisées (nanofeuillets et/ou nanoéponges en utilisant des agents structurants bifonctionnels). Ces matériaux sont comparés aux zéolithes conventionnelles, afin d'étudier l'influence de la morphologie sur la cinétique et la capacité de piégeage de COVs. Les caractéristiques structurales et texturales des zéolithes synthétisées ont été étudiées par ORX, MEB, manométrie d'adsorption/désorption de diazote, ATG-ATD, RMN du solide. Enfin, la capacité d'adsorption d'une molécule modèle, le n-hexane, au sein de ces zéolithes a été étudiée par thermogravimétrie. Dans le cas des zéolithes de type MFI et *BEA, les zéolithes hiérarchisées ont montré une augmentation de la capacité de piégeage en n-hexane par rapport aux zéolithes conventionnelles. La capacité de piégeage en n-hexane a été multipliée par 7 dans le cas des nanoéponges de type *BEA et par 6 dans le cas des nanocristaux de type *BEA comparés aux microcristaux de type *BEA (693 mg/g vs 103 mg/g et 591 mg/g vs 103 mg/g, respectivement). / Volatile organic compounds (VOCs) are the most abundant organic pollutants. Among the various solutions to fight against this pollution, the use of molecular adsorbents appears as a potential alternative for the control of contamination. The porous materials have many advantages due to their low cost, their physical characteristics and their useful properties related to their structure and their large surface area. However, conventional synthesis of zeolites generally lead to micrometer size crystals. The capacity and the kinetics of adsorption that are sensitive to the diffusion and the surface phenomena could be potentially improved by the use of zeolite nanocrystals or hierarchical products (micro / mesoporous). These nanomaterials have high potential due to their small size and their exalted outer surface that promote access of pollutants and improve the adsorption capacity. ln the thesis work, we synthesized zeolites with different structural types such as FAU, MFI and *BEA. Each structure type was synthesized in different morphologies such as nanosponges and /or nanosheets using a bifunctional structuring agent, as well as nanocrystals by the clear solution method. These materials were compared with conventional micrometer-sized zeolites. The purity and the porous texture have been characterized by using XRD, SEM, nitrogen adsorption/desorption techniques, TGA-DTA and solid state NMR. Finally, the adsorption capacity of a model molecule, the n-hexane, in these zeolites have been studied by thermogravimetry. In the case of *BEA and MFI-type zeol ites, the hierarchical zeolites showed an increase of the adsorption capacity of n-hexane compared to conventional zeolites. The adsorption capacity of n-hexane was multiplied by 7 in the case of *BEA-type nanosponges and by 6 in the case of the *BEA-type nanocrystals compared to *BEA_type microcrystals (693 mg / g vs 103 mg / g and 591 mg / g vs 103 mg / g, respectively).
169

Exposition de la peau aux produits chimiques : méthodologie et évaluation de la décontamination par la terre de foulon / Cutaneous exposure to chemicals : methods and evaluation of decontamination with fuller’s earth

Roul, Annick 03 September 2018 (has links)
L’exposition cutanée aux produits chimiques par des rejets criminels ou accidentels impose une méthode de décontamination rapide et efficace pour sauver des vies et limiter le transfert de la contamination. L’exploration bibliographique recense des produits toxiques (armes chimiques, toxiques industriels) ainsi que les décontaminants naturels ou synthétiques et leurs méthodes d’application dans un contexte d’intervention sur le terrain. Le sujet vise à la qualification d’un outil de décontamination, la terre de foulon dans des formulations simples, faciles à mettre en œuvre en urgence par les services de Sécurité civile (sapeurs-pompiers). Le travail réalisé comporte :La caractérisation chimique et structurale de la poudre de terre de foulon NBC-Sys qui a permis d’identifier le composant principal : la palygorskite, La formulation et la caractérisation galénique et physico-chimique (granulométrie, zêta potentiel) en milieu concentré et milieu dilué des systèmes dispersés,La capacité d’adsorption de la terre de foulon et ses formulations vis-à-vis d’un modèle contaminant, le 4-cyanophenol, d’intérêt pour l’évaluation de la décontamination, in vitro en milieu aqueux, ex vivo sur explant cutané. L’adsorption du 4-CP en solution aqueuse (10, 100 et 500 mg/L-1) est rapide (5-15min) au contact de la terre de foulon, varie avec le ratio terre de foulon/4-CP, atteint un plateau (saturation) entre 45 et 60 min, l’équilibre entre 60 min et 120 min. Les suspensions de terre de foulon sont plus efficaces (90%) pour la décontamination que les poudres (70%) et l’eau (60%) dans des conditions expérimentales identiques. L’évaluation de la terre de foulon et ses formulations sur les paramètres physiologiques de la peau (perte insensible en eau et conductance) in vivo chez l’homme ne montre pas d’altération de la fonction barrière cutanée.L’ensemble est un premier pas vers une référence (qui n’existe pas actuellement), incluant une méthodologie de décontamination chimique / Cutaneous exposure to contaminants chemicals after criminal or accidental release enforces a rapid and efficient decontamination to save lives and avoid cross contamination. A bibilographic exploration of this work identifies toxic chemical (chemical warfare agents, toxic industrial chemicals), raw and synthetic decontaminants and their application methods applied in emergency. The aim of this study focuses on a decontamination tool qualification, the fuller’s earth (FE), simple formulated, easy to apply in emergency by civil Security services (fire fighter brigades). The work performed includes :The chemical and structural characterization of the powder of fuller’earth NBC-Sys , that lead to identify the palygorskite as main component, The formulation of dispersed systems and their physico chemical characterization (granulometry, zêta potentiel) in concentrated or diluted medium. The adsorption capacity of the FE and formulations for a contaminant model, the 4-cyanophenol, to assess decontamination in vitro, in aqueous medium, ex vivo on cutaneous explant.4-CP adsorption in aqueous solutions (10, 100 et 500 mg/L-1) is rapid (5-15min), when contact with FE, vary with the ratio FE/ 4-CP, to reach a plateau phase (saturation) between 45 and 60 minutes, and an steady state between 60 and 120 min. FE suspensions are more efficient (90%) than powder (70%) and water (60%) in the same experimental conditions. L’évaluation de la terre de foulon et ses formulations sur les paramètres physiologiques de la peau (perte insensible en eau et conductance) in vivo chez l’homme ne montre pas d’altération de la fonction barrière cutanée. FE and its suspensions were assessed on physiological skin parameters (Transepidermal water loss and conductance) in vivo in a human study and exhibit no alteration on the skin barrier function. Results obtained is a first step towards a reference (that actually don’t exist) including a chemical decontamination method
170

Survival of infectious agents and detection of their resistance and virulence factors

Tano, Eva January 2015 (has links)
In the first study, three different transport systems for bacteria were evaluated. The CLSI M40-A guideline was used to monitor the maintenance of both mono- and polymicrobial samples during a simulated transportation at room temperature that lasted 0-48 h. All systems were able to maintain the viability of all organisms for 24 h, but none of them could support all tested species after 48 h.  The most difficult species to recover was Neisseria gonorrhoeae, and in polymicrobial samples overgrowth was an observed problem. The aim of the second study was to study the presence of TSST-1 and three other important toxin genes in invasive isolates of Staphylococcus aureus collected during the years 2000-2012 at two tertiary hospitals. The genes encoding the staphylococcal toxins were detected by PCR, and whole-genome sequencing was used for analyzing the genetic relatedness between isolates. The results showed that the most common toxin was TSST-1, and isolates positive for this toxin exhibited a clear clonality independent of year and hospital. The typical patient was a male aged 55-74 years and with a bone or a joint infection. The third study was a clinical study of the effect of silver-based wound dressings on the bacterial flora in chronic leg ulcers. Phenotypic and genetic silver-resistance were investigated before and after topical silver treatment, by determining the silver nitrate MICs and by detecting sil genes with PCR. The silver-based dressings had a limited effect on primary wound pathogens, and the activity of silver nitrate on S. aureus was mainly bacteriostatic. A silver-resistant Enterobacter cloacae strain was identified after only three weeks of treatment, and cephalosporin-resistant members of the Enterobacteriaceae family were relatively prone to developed silver-resistance after silver exposure in vitro. The last study was undertaken in order to develop an easy-to-use method for simulating the laundering process of hospital textiles, and apply the method when evaluating the decontaminating efficacy of two different washing temperatures. The laundering process took place at professional laundries, and Enterococcus faecium was used as a bioindicator. The results showed that a lowering of the washing temperature from 70°C to 60°C did not affect the decontamination efficacy; the washing cycle alone reduced the number of bacteria with 3-5 log10 CFU, whereas the following tumble drying reduced the bacterial numbers with another 3-4 log10 CFU, yielding the same final result independent of the washing temperature. To ensure that sufficient textile hygiene is maintained, the whole laundering process needs to be monitored. The general conclusion is that all developmental work in the bacterial field requires time and a large strain collection.

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