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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.
131

Výskyt biogenních aminů a polyaminů ve zrajících sýrech po ukončení doby spotřeby / Content of biogenic amines and polyamines in expired ripening cheeses

VODEHNALOVÁ, Klára January 2012 (has links)
The aim of this thesis was to observe the occurrence of biogenic amines and polyamines in selected types of ripening cheeses and to assess the content of the materials since the expiration date. Content of biogenic amines and polyamines in chosen samples was monitored last day of the expiration date, a week after the expiration date, two weeks after the expiration date, and after four weeks from the end of the expiration date.
132

Sledování obsahu biogenních aminů a polyaminů při skladování a kuchyňských úpravách jedlých hub. / Changes of biogenic amines and polyamines content during storage and heat treatments of edible mushrooms.

PEKÁRKOVÁ, Jana January 2013 (has links)
The target of this thesis was found content of eight biogenic amines and polyamines, specifically putrescine (PUT), spermidine (SPD), spermine (SPM), histamine (HIM), cadaverine (CAD), 2-phenylethylamine (PEA), tyramine (TYM) and tryptamine (TRM) in growed Agaricus hortensis during storage, frozen and heat treatment. There are many information dealing with these amines in the food in this time, but unfortunately data on the content of amines in edible mashrooms in literature are still missing. The samples were providing from company České houby a.s. in Soběslav. Those mushrooms were immediately processed. Frozen samples in PE sack (plastic bags) were tracked during three months. Boiled, blanched and raw samples of mushrooms were analysed in the beginning of concentration at day 0 and then 1, 2 and 4 days at 6 °C in the storage. Some samples of each experiment monitored after one day of storage at 22°C. Absolutely the highest concentrations found in all experiments with SPD. Changes in the content of amine modified and raw mushrooms during 4 days of storage at 6 ° C flow in both directions. The most important changes are visible immediately after blanching - a significant increase in TYM and even more pronounced in SPM. The increase was also showed in the content of the cooked mushrooms, in the SPD and to a higher volume in SPM. Storage at 22 ° C was mostly affected content PEA - the cooked mushrooms content significantly decreased, but blanched mushrooms increased. Also in raw mushrooms lead storage at this temperature for a significant increase in the SPM. Freezing substantially affect any of the amines. TRM and CAD analysis were not detected; HIM at lower limit was detected after cooking mushrooms and after storage of raw mushrooms at 22 ° C. I hope that the observed data can help extend the data in the literature and offers the opportunity to further focus of research in the field of biogenic amines in edible mushrooms.
133

Caracterização de aerossóis no Pantanal Mato-Grossense

Santos, Anna Carolinna Albino 17 February 2014 (has links)
Submitted by Valquíria Barbieri (kikibarbi@hotmail.com) on 2018-04-12T21:14:58Z No. of bitstreams: 1 DISS_2014_Anna Carolinna Albino Santos.pdf: 2580158 bytes, checksum: 7c462cc6d9578f7ac6db50c5de436a44 (MD5) / Approved for entry into archive by Jordan (jordanbiblio@gmail.com) on 2018-04-27T14:47:45Z (GMT) No. of bitstreams: 1 DISS_2014_Anna Carolinna Albino Santos.pdf: 2580158 bytes, checksum: 7c462cc6d9578f7ac6db50c5de436a44 (MD5) / Made available in DSpace on 2018-04-27T14:47:45Z (GMT). No. of bitstreams: 1 DISS_2014_Anna Carolinna Albino Santos.pdf: 2580158 bytes, checksum: 7c462cc6d9578f7ac6db50c5de436a44 (MD5) Previous issue date: 2014-02-17 / CAPES / O Pantanal constitui em uma região de enorme importância ecológica e socioeconômica. A região pantaneira é a maior área alagável contínua existente e tem-se apresentando interesse nos estudos relacionados ao clima para entender os mecanismos antrópicos e naturais que são capazes de regular a composição da atmosfera. Pode-se avaliar o impacto das queimadas e, sobretudo, determinar a variabilidade sazonal da concentração de aerossóis nessa região. O objetivo desse trabalho foi caracterizar a composição elementar de aerossóis, a variabilidade sazonal da concentração de material particulado, e avaliar as fontes de material particulado no Pantanal Mato-Grossense. As amostras de aerossóis atmosféricos foram coletadas de abril de 2012 a agosto de 2013 na Baía das Pedras, localizada no Pantanal Matogrossense, Brasil. O dispositivo de amostragem consistiu em amostradores de particulado fino e grosso (AFG), que separam a fração fina do aerossol (dp˂ 2,5 μm) e a fração grossa (2,5 – 10 μm). A análise de composição elementar foi realizada com Fluorescência de Raios-X por energia dispersiva. Três tipos de fontes de aerossóis foram estimadas através do PMF (Positive Matrix Factorization): emissões biogênicas naturais, ressuspensão de poeira do solo e queima da biomassa. Na estação seca observou-se uma média de 0,00866 μg/m3 para o material particulado fino e 0,00721 μg/m3 para o material particulado grosso. A fração conhecida do MPF representou 20,8 % de sua massa na estação seca, sendo a do MPG representou 20,1 %. Na estação chuvosa observou-se uma média de 0,00424 μg/m3 para MPF e 0,00544 μg/m3 para MPG. A fração conhecida do MPF representou 24,5 % e MPG, 23,8 %. / The Pantanal is a region of enormous ecological and socioeconomic importance. The Pantanal is the largest wetland existing continuous and has been showing interest in climate-related studies to understand the anthropogenic and natural mechanisms that are able to regulate the composition of the atmosphere. Can assess the impact of fires and especially to determine the seasonal variability of aerosol concentration in this region. The purpose of this study was to characterize the aerosol elemental composition, the seasonal variability of concentrations, and to evaluate the sources of particulate matter in the Pantanal Mato Grossense. Atmospheric aerosol samples were collected from April 2012 to August 2013 at Baía das Pedras, located in Pantanal, Brazil. The sampling device consisted of particulate samplers (SFU – stacked filter units), which separates the fine fraction ( dp ˂ 2.5 μm ) and the coarse fraction ( 2,5 - 10 μm ) of the aerosols. The elemental analysis was done using X- ray fluorescence by dispersive energy. Three types of aerosol sources were determined for both seasons by PMF (Positive Matrix Factorization) analysis: natural biogenic emissions, resuspension of soil dust, and biomass burning, being sources of fine and coarse particles. In the dry season there was an average of 0.00866 μg/m3 for fine particulate matter and 0.00721 μg/m3 for coarse particulate matter. A known fraction of MPF represented 20.8 % of its mass in the dry season, with an MPG represented 20.1 %. In the rainy season there was an average of 0.00424 μg/m3 for MPF and 0.00544 μg/m3 for MPG. A known fraction of MPF represented 24.5% and MPG, 23.8%.
134

Estudo do ciclo biogeoquímico do silício em diferentes sistemas marinhos como ferramenta para identificação de alterações ambientais de origem natural e/ou antrópica / Study of silicon biogeochemical cycle in different marine systems as a tool to identify natural and/or anthropic environmental alterations

Ana Teresa Cordeiro Cid Bastos 25 July 2014 (has links)
O silício encontra-se no meio marinho nas formas: dissolvida e particulada (biogênica e litogênica). O ciclo biogeoquímico deste elemento está sujeito à influência sazonal e às alterações antrópicas. Este trabalho visa entender a relação entre as diferentes formas de silício como resposta a processos de origem natural e antrópica em diferentes ambientes (Estreito de Bransfield, Antártica; Complexo Estuarino-Lagunar de Cananeia-Iguape, SP; região costeira de Recife, PE). O Estreito de Bransfield pela sua localização remota é das áreas estudadas, a menos impactada pelo homem. A região nordeste do Estreito mostrou menores concentrações de silicato na superfície associadas à menor diversidade fitoplanctônica, constituída por diatomáceas do gênero Corethron que facilitam o afundamento de Si e a remineralização do C e N. Já na região sudoeste do Estreito a concentração de silicato foi maior, assim como a influência do degelo, que contribui para uma maior disponibilidade de ferro, indicada pelo traçador Si*, aumentando a diversidade fitoplanctônica. Nesta região também houve a presença de espécies que facilitam o afundamento de C e N e a remineralização de Si. O Complexo Estuarino-Lagunar de Cananeia-Iguape, apresentou sinais de impacto antrópico sobretudo no setor norte (Iguape), mostrado pelas diferentes frações do silício que foram excelentes indicadores de processos erosivos. No setor sul a influência antrópica não foi observada, assim o silício indicou processos de origem natural como a sedimentação, evidenciada pela remoção do BSi e do LSi, e a ressuspensão onde as concentrações das frações particuladas foi maior. A região costeira de Recife está sob a influência dos aportes fluviais provenientes dos rios Capibaribe e Beberibe. A distribuição da maioria dos parâmetros, incluindo o silicato e o BSi, mostraram esta influência vinda de oeste, atingindo a barreira na saída do porto e se propagando em direção a nordeste. Devido ao maior aporte de nutrientes nas estações mais próximas à costa a produção primária foi incentivada, evidenciada pelos maiores valores de clorofila-a e BSi. Nas estações mais distantes da costa os parâmetros tiveram valores característicos de áreas oligotróficas, com as frações de silício mostrando concentrações bastante baixas. O silício se mostrou um excelente indicador de aportes continentais naturais e antrópicos. São poucos os trabalhos que quantificam o BSi e o LSi no meio aquático, assim este estudo consiste em um ponto inicial para o entendimento do silício particulado em águas brasileiras. / Silicon is found in the marine environment under the forms: dissolved and particulate (biogenic and lithogenic). The biogeochemical cycle of this element is subject to seasonal influences and anthropogenic changes. This work aims to understand the relationship between different forms of silicon in response to processes of natural and anthropogenic origin in different environments (Bransfield Strait, Antarctica; Cananeia-Iguape Estuarine-Lagoon Complex, SP ; coastal region of Recife, PE) . The Bransfield Strait is, of the studied areas, the least impacted by man, because of its remote location. The northeastern Strait region showed lower silicate concentrations associated with lower phytoplankton diversity, consisting of diatoms of the genus Corethron that facilitate sinking af Si and remineralization of C and N. In the southwestern region of the Strait silicate concentration was higher, as well as the influence of thaw, which contributes to increased iron availability, indicated by Si* tracer, that increases phytoplankton diversity. In this region there was also the presence of species that facilitate the sinking of C and N and the remineralization of Si. Cananeia-Iguape Estuarine -Lagoon Complex, showed signs of anthropogenic impact especially in the northern sector (Iguape), showed by silicon different fractions, which were excellent indicators of erosion processes. In the southern sector, anthropogenic influence was not observed. Silicon indicated processes of natural origin, like sedimentation, evidenced by the removal of BSi and LSi, and resuspension where concentrations of particulate fractions was higher. The coastal region of Recife is under influence of fluvial inputs from Capibaribe and Beberibe rivers. The distribution of most parameters, including silicate and BSi, showed this influence coming from the west, reaching the barrier at the port exit and propagating toward northeast. Due to higher nutrient availability in the stations nearest to the coast, primary production was encouraged, evidenced by high values of chlorophyll-a and BSi. In the stations more distant to the coast, the parameters had values characteristic of oligotrophic areas , with the forms of silicon showing very low concentrations. Silicon proved to be an excellent indicator of continental natural and anthropogenic contributions. There are few studies that quantify the BSi and LSi in the aquatic environment, therefore this study is a starting point for understanding particulate silicon in Brazilian waters.
135

Aminas biogenicas, aminas volateis, triptofano livre e ureia como indices quimicos de qualidade e frescor do pescado / Biogenic amines, volatile amines, free tryptophan and urea as chemical indices for quality and freshness evaluation of fish and sellfish

Lapa Guimarães, Judite 08 December 2005 (has links)
Orientadores: Pedro Eduardo de Felicio, Jana Pickova / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-04T20:04:37Z (GMT). No. of bitstreams: 1 LapaGuimaraes_Judite_D.pdf: 14813702 bytes, checksum: ceaf92aa9f32ece3f3b4c5ef620aa4ee (MD5) Previous issue date: 2005 / Resumo: Em função da alta perecibilidade do pescado, a avaliação do frescor e qualidade deste alimento deve ser precisa e baseada em métodos consolidados. Bases nitrogenadas voláteis (BNV), trimetilamina (TMA), aminas biogênicas, nucleotídeos, uréia e triptofano livre têm sido propostos como índices de frescor para pescado e podem ser efetivos ou não dependendo da espécie de pescado, microbiota contaminante e condições de armazenamento. A quantificação dos teores de aminas biogênicas é também importante devido ao seu potencial tóxico. Os objetivos deste estudo foram avaliar a utilidade das aminas biogênicas, BNV, TMA, triptofano livre e uréia como índices de qualidade e frescor em peixes e moluscos cefalópodes, desenvolver e avaliar sistemas de solventes para separação de aminas biogênicas por cromatografia de camada delgada e avaliar o efeito do tempo e temperatura de derivatização sobre a conversão das aminas biogênicas em seus derivados dansilados. Derivados dansilados de agmatina (AGM), putrescina (PUT), triptamina (TRY), cadaverina (CAD), histamina (HIS), espermidina (SPD), espermina (SPM), tiramina (TYR) e feniletilamina (PHE) foram separados utilizando-se o sistema de solventes clorofórmio: éter dietílico: trietilamina (6:4:1 - v/v) seguido de clorofórmio: trietilamina (6:1 ¿ v/v). A melhor condição para derivatização das aminas biogênicas com cloreto de dansila foi 1h a 40oC. AGM permaneceu no local de aplicação (RF=0,0), o que indica que a metodologia deve ser utilizada com cautela para a determinação desta amina. As percentagens de recuperação de TRY, SPM, SPD e TYR foram baixas, indicando que a metodologia para extração destas aminas deve ser aperfeiçoada. BNV e TMA foram consideradas índices de frescor inadequados para bacalhau (Gadus morhua) e hadoque (Melanogrammus aeglefinus). O padrão de produção mais acentuado a partir da segunda semana de armazenamento, caracterizou as aminas voláteis e as aminas biogênicas CAD e PUT como índices de deterioração para bacalhau e hadoque. Uréia se mostrou inadequada como índice de qualidade para as duas espécies de pescado estudadas. Modelos de regressão linear e quadrática indicaram um aumento progressivo dos teores de AGM em lula (Illex coindetii), de uréia em sépia (Sepia officinalis), e de BNV e triptofano livre nas duas espécies de cefalópodes desde o início do armazenamento. BNV e triptofano livre foram considerados bons índices de frescor para I. coindetii e S. officinalis, pois seus teores aumentaram significativamente (p<0,05) desde o início do armazenamento. AGM e uréia foram consideradas índices de deterioração para I. coindetii e S. officinalis, respectivamente. Os teores de TMA (% NNP) aumentaram significativamente (p<0,05) durante a primeira semana de armazenamento em I. coindetii o que sugere sua utilidade como índice de frescor para lula. Para S. officinalis TMA é mais adequada como índice de deterioração / Abstract: Fish and shellfish muscle is highly susceptible to spoilage during storage. Because quality quickly decreases during storage reliable chemical indices for quality and freshness evaluation are greatly needed. Total volatile bases-nitrogen (TVB-N), trimethylamine (TMA), biogenic amines, nucleotides, urea and free tryptophan have been suggested as freshness indices for fish and shellfish. Such indices are useful depending on the species, microbial flora and storage conditions. Biogenic amines levels are also cause of concernment due to their toxicological effects. The objectives of this study were to evaluate the usefulness of biogenic amines, TVB-N, TMA, free tryptophan and urea as freshness and quality indices for fish and cephalopods; to develop and evaluate solvent systems for biogenic amines separation by thin-layer chromatography; and to evaluate the effects of time and temperature of derivatisation on the conversion of biogenic amines to their dansyl derivatives. Dansyl derivatives of agmatine (AGM), putrescine (PUT), tryptamine (TRY), cadaverine (CAD), histamine (HIS), spermidine (SPD), spermine (SPM), tiramine (TYR) and phenylethylamine (PHE) were separated using the solvent system chloroform: diethyl ether: triethylamine (6:4:1 ¿ v/v), followed by chloroform: triethylamine (6:1 ¿ v/v). The best dansylation condition was 1h at 40oC. AGM remained at the start position, indicating the determination of AGM by this method should be considered with caution. The percentages of recovery of TRY, SPM, SPD and TYR were low, indicating that the extraction methodology must be improved. TVB-N and TMA were considered inappropriate as freshness indices for cod (Gadus morhua) and haddock (Melanogrammus aeglefinus). CAD and PUT showed the greatest increases during the storage, but their levels did not increase significantly (p<0.05) during the first week. Volatile amines and biogenic amines were characterized as spoilage indices for G. morhua and M. aeglefinus due to the intense increasing of their amounts from the second week of storage. Urea was not useful as a quality index for cod and haddock. Linear and quadratic models indicated progressive increasing of AGM levels in squid (Illex coindetii), urea in cuttlefish (Sepia officinalis) and also increasing of TVB-N and free tryptophan in both cephalopods, since the beginning of the storage. TVB-N and free tryptophan were considered good freshness indices for both cephalopod species, because their levels significantly increased (p<0.05) during the first week of storage. AGM and urea were useful as spoilage indices for I. coindetii and S. officinalis, respectively. It was observed a significant increase of TMA (% of NNP) during the first week of storage in I. coindetii indicating the TMA usefulness as freshness index for squid. For S. officinalis TMA was a good spoilage index / Doutorado / Doutor em Tecnologia de Alimentos
136

Avaliação dos efeitos digestivos, fermentativos e imunológicos de leveduras (Saccharomyces cerevisiae) inativadas e enriquecidas em meio de cultura em dietas para gatos adultos / Effects of increasing levels of yeast (Saccharomyces cerevisiae) on digestibility, fecal fermentation and immunological parameters in diets for adult cats

Laura Fantucci de Oliveira Matheus 19 August 2016 (has links)
As leveduras Saccharomyces cerevisiae são consideradas importantes matérias primas na nutrição animal pela sua capacidade prebiótica. Os prebióticos são compostos não digeridos pelo organismo animal, mas que são fermentados pelos microrganismos do trato gastrintestinal, cujos produtos são capazes de prover benefícios ao hospedeiro. A fermentação depende de fatores como: substrato utilizado para o seu crescimento, método de fermentação, modo e condição de secagem e idade das células. Assim, os processos produtivos modernos têm como intuito a produção de leveduras com elevado potencial prebiótico. Este estudo objetivou avaliar os efeitos de teores crescentes de leveduras com metabólitos ativos (LSC; baseada na fermentação de substratos específicos) na digestibilidade aparente dos nutrientes da dieta, microbiota e produtos da fermentação fecal e parâmetros imunológicos de gatos adultos. Foram utilizados 27 gatos adultos, idade média de 9,44&#177;5,35 anos, machos e fêmeas, sem raça definida e saudáveis. Os animais foram distribuídos em delineamento em blocos casualizados (idade), constituído de três tratamentos experimentais, denominados: DC (dieta controle), LSC 0,3 (dieta controle com 0,3% de leveduras com metabólitos ativos) e LSC 0,6 (dieta controle com 0,6% de leveduras com metabólitos ativos). Os resultados obtidos foram analisados através do programa computacional Statistical Analysis System (SAS Institute Inc., 2004), sendo considerados significativos valores de p&lt;0,05 e as médias comparadas pelo teste de Tukey. Verificou-se que a inclusão do aditivo alterou apenas a digestibilidade aparente da fibra bruta, da matéria mineral e energia metabolizável (p&lt;0,05). Já em relação aos produtos da fermentação e microbiota das fezes, observou-se redução em ácido lático (p&#61;0,0040) e Clostridium perfringens (p&#61;0,0226) com a inclusão do prebiótico e diminuição do ácido isovalérico (p&#61;0,0144) no tratamento LSC 0,3. Pode-se concluir que o aditivo, nos teores de inclusão avaliados, parece apresentar potencial prebiótico em relação aos produtos da fermentação e microbiota fecal / Saccharomyces cerevisiae yeast are considered important raw materials in animal nutrition due their prebiotic capacity. Prebiotics are compounds not digested by animal organism, but are fermented by microorganisms in the gastrointestinal tract, which products are capable of providing benefits to the host. The fermentation depends on factors such as: substrate used for growth, fermentation method, way and drying condition and age of the cells. Thus, modern production processes have the objective of producing yeast with high prebiotic potential. This study aimed to evaluate the effects of increasing levels of yeast with active metabolites (LSC) based on the fermentation of specific substrates on apparent digestibility of diet nutrients, microbiota and fecal fermentation products and immunological parameters in adult cats. Twenty seven male or female cats with mean weight of 4.19 &#177; 0.83kg and mean age of 9.44 &#177; 5.35 years were used and distributed in an unbalanced randomized block design (age), consisting of three experimental treatments, DC (control diet), LSC 0.3 (control diet with 0.3% yeast with active metabolites) and LSC 0.6 (control diet with 0.6% yeast with active metabolites). The results were analyzed using the computer program Statistical Analysis System (SAS Institute Inc., 2004), with significance level of p&lt;0.05 and the averages compared by Tukey test. The inclusion of the additive only changed the apparent digestibility of crude fiber and mineral content (p&lt;0.05). Regarding the fermentation products and microbiota of feces, there was a reduction in lactic acid (p&#61;0,0040) and Clostridium perfringens (p&#61;0,0226) with inclusion of prebiotic and decreased of isovalerate (p&#61;0,0144) in the LSC 0.3 treatment. It can be concluded that the additive, in the levels of inclusion assessed, seems to have prebiotic potential on fecal fermentation products and microbiota
137

Caracterização de nanopartículas de prata e sua aplicação na produção de tecidos antimicrobianos / Characterization of silver nanoparticles and their application in the production of antimicrobial fabric

Ballottin, Daniela Pott Marinho, 1987- 05 August 2014 (has links)
Orientadores: Ljubica Tasic, Priscyla Daniely Marcato Gaspari / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-25T19:45:44Z (GMT). No. of bitstreams: 1 Ballottin_DanielaPottMarinho_D.pdf: 4687735 bytes, checksum: 78a932e6ae81a2c4a51ae94b6bf0c65f (MD5) Previous issue date: 2014 / Resumo: Esta tese compreende a produção biogênica e extracelular de nanopartículas de prata (AgNP) utilizando o fungo Fusarium oxysporum, a caracterização físico-química e bioquímica de AgNP e de proteínas, respectivamente. As partículas obtidas foram caracterizadas por técnicas microscópicas, espectroscópicas e de espalhamento dinâmico de luz, as quais forneceram informações em relação a morfologia, tamanho, composição elementar, carga superficial e cristalinidade das partículas. A presença de proteínas estabilizadoras ao redor das partículas foi evidenciada por UV-Vis e TEM. Estas macromoléculas também foram estudas e caracterizadas por diferentes técnicas, tais como, fluorescência, dicroísmo circular, FTIR e Raman. Além disso, foram realizadas análises de eletroforese em gel sendo possível estimar a massa molar das proteínas que estabilizam as AgNP. Algumas destas proteínas foram identificadas por espectrometria de massas, a qual permitiu a obtenção de resultados promissores e inéditos, uma vez que não há na literatura nenhum relato sobre a identificação de proteínas envolvidas na síntese e/ou na estabilização das AgNP. Adicionalmente, foi estudada a atividade antimicrobiana das AgNP frente a diversos micro-organismos patogênicos, como duas espécies de Candida sp. (C. albicans e C. parapsilosis), as quais causam infecções hospitalares, e Xanthomonas axonopodis pv. citri (Xac), uma bactéria patogênica causadora do cancro cítrico, doença com sérias consequências para citricultura brasileira. Nestes estudos foi verificada a alta atividade antimicrobiana das partículas com a atividade inibitória mínima (MIC) da ordem de ?g mL-1. Cito- e genotoxicidade em diferentes organismos e células também foram investigadas, demonstrando que em concentrações utilizadas neste trabalho, as AgNP não apresentam efeito cito- ou genotóxico. São mostrados também resultados da impregnação das AgNP em tecido de algodão e a atividade antimicrobiana deste material frente a C. albicans, C. parapsilosis e Xac / Abstract: This thesis comprises the biogenic and extracellular production os silver nanoparticles (AgNP) using the Fusarium oxysporum fungus, the physic-chemical and biochemical characterization of AgNP and proteins, respectively. The obtained particles were characterized by microscopic, spectroscopic and dynamic light scattering techniques, which provided information regarding the morphology, size, elemental composition, particle surface charge and cristallinity. The presence of surrounding proteins, which stabilize particles was evidenced by UV-Vis and TEM. These macromolecules have also been studied and characterized by different techniques, such as, fluorescence, circular dichroism, Raman and FTIR. Moreover, del electrophoresis analysis were performed ans it was possible to estimate the molar weight of proteins. Some of these were identified by mass spectrometry, which allowed to obtain novel and promising results since there is no reports on the identification of proteins involved in synthesis and/or stabilization of AgNP. Additionally, it was studied the antimicrobial activity of AgNP against several pathogenic micro-organisms, such as, Candida sp. (C. albicans and C. parapsilosis), which cause nosocomial infections, and Xanthomonas axonopodis pv. citri (Xac), a pathogenic bacterium that causes citrus canker, a disease with serious consequences for the Brazilian citrus industry. In these studies it was investigated the high antimicrobial activity of particles through the minimum inhibitory concentration (MIC) values (order of ?g mL-1). Cyto- and genotoxicity in different organisms and cells have also been investigated, showing thet at determined concentrations, AgNP have no cyto- and genotoxic effects. Results of impregnation of AgNP in cotton fabrics and its antimicrobial activity are also shown against C. albicans, C. parapsilosis and Xac / Doutorado / Quimica Organica / Doutora em Ciências
138

Nanopartículas de prata : biossíntese, investigação das atividades antibacteriana, antifúngica e citotoxicidade / Silver nanoparticles : biosynthesis, investigation of antibacterial and antifungal activity and cytotoxicity

Silva, Juliana de Cassia, 1984- 26 August 2018 (has links)
Orientador: Patricia da Silva Melo, Priscyla Daniely Marcato / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Aplicadas / Made available in DSpace on 2018-08-26T08:22:25Z (GMT). No. of bitstreams: 1 Silva_JulianadeCassia_M.pdf: 2326263 bytes, checksum: 5774dc06c3b8cd0a38cfb05b3dbd8247 (MD5) Previous issue date: 2014 / Resumo: Com o objetivo de entender melhor a toxicidade das nanopartículas de prata biogênicas, estas foram preparadas utilizando a rota biotecnológica e extracelular com o fungo Fusarium oxysporum. As nanopartículas de prata biogênicas foram caracterizadas por microscopia eletrônica de transmissão (TEM) e absorbância na região do UV/Visível. O tamanho das nanopartículas foi determinado pela a técnica de análise de rastreamento de nanopartículas (NTA) utilizando o equipamento NanoSight, e por espectroscopia de correlação de fótons utilizando o equipamento ZetaSizer. O potencial zeta das partículas também foi avaliado no ZetaSizer. A atividade antimicrobiana, a citotoxicidade e os mecanismos de ação das nanopartículas de prata biogênicas em células V79 também foram investigados. A produção de nanopartículas de prata foi evidenciada pela presença da banda de absorção de plasma ('lâmbda' = 450 nm) e por TEM sendo observadas partículas esféricas com o tamanho de 15-22 nm. A atividade antibacteriana e antifúngica das nanopartículas de prata foi avaliada contra Staphylococcus aureus (MIC 1,47 µg mL-1), Salmonella typhymurium (MIC 0,36 µg mL-1), Escherichia coli (MIC 0,73 µg mL-1), Aspergillus niger (MIC 5,90 µg mL-1) e Trichophytum rubrum (MIC 2,95 µg mL-1). Além disso, a atividade bactericida das nanopartículas de prata foi diminuída na presença de glutationa reduzida, indicando que a eficácia antimicrobiana está provavelmente relacionada com a indução de estresse oxidativo. As nanopartículas de prata exibiram citotoxicidade dose dependente em células V79. Na concentração de 8,49 µg mL-1 as nanopartículas de prata promoveram 51% de morte celular avaliada pela redução do MTT e 37 % em ensaios de DNA. A presença de glutationa (307,3 µg mL-1) aumentou em 17 % a viabilidade celular, atingindo 66% de células viáveis no ensaio MTT e em 25 % no ensaio de DNA, atingindo 88% de células viáveis. Estes resultados podem indicar que os efeitos citotóxicos induzidos pelo tratamento de nanopartículas de prata biogênicas podem estar relacionadas com o estresse oxidativo. Este efeito pode ser muito importante na terapia de câncer e de antibióticos, e também para tratamento de doenças neurodegenerativas entre outras / Abstract: Aiming to understand better the toxicity of biogenic silver nanoparticles, these were prepared using biotechnological extracellular route and fungus Fusarium oxysporum. biogenic silver nanoparticles were then characterized by transmission electron microscopy and UV/Vis. Their size and zeta potential were determined using the nanoparticle tracking analysis software by Nanosight, photon correlation spectroscopy and zeta potential techniques. The antimicrobial activity, cytotoxicity and in vitro mechanism of biogenic silver nanoparticles action in V79 cells were also investigated. The biogenic silver nanoparticles production was evidenced by the presence of the plasmon absorption band ('lâmbda'= 450 nm) and spherical particles with the size of 15-22 nm were obtained. The biogenic silver nanoparticles antimicrobial and antifungal activity against Staphylococcus aureus (MIC 1.47 'mu'g mL-1), Salmonella typhymurium (MIC 0.36 'mu'g mL-1), Escherichia coli (MIC 0.73 ?g mL-1), Aspergillus niger (MIC 5.90 ?g mL-1) and Trichophytum rubrum (MIC 2.95 'mu'g mL-1) were measured. Furthermore, the bactericidal activity of AgNPbio decreased in the presence of reduced glutathione (GSH) indicating that antimicrobial effectiveness is probably related to oxidative stress induction. The biogenic silver nanoparticles exhibited cytotoxicty in some extent regarding V79 cells. At the concentration of 8.49 'mu'g mL-1 biogenic silver nanoparticles provoked 51% cell death in the MTT and 37% in DNA assays. The presence of glutathione (GSH, 307.3 ng mL-1) increased 17% cell viability on MTT and 25% on DNA assays. Obtained results may point out that the cytotoxic effects induced by biogenic silver nanoparticles treatment could be related to the oxidative stress. This effect can be very important in the cancer and antibiotic therapy and also for neurodegenerative and many other diseases treatments / Mestrado / Metabolismo e Biologia Molecular / Mestra em Ciências da Nutrição e do Esporte e Metabolismo
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Tvorba biogenních aminů v dvouplísňovém sýru / Production of biogenic amines in double moulded cheese

Šuláková, Miroslava January 2009 (has links)
For production of double moulded chesses are used lactic acid bacteria, which can be present in a form of non-starter lactic acid bacteria or as starter or adjunct culture. Genera Lactobacillus spp. and Enterococcus spp. are prevalent microorganisms present in these cultures. Of course, these microorganisms are for us interesting because of their possibility of coagulation, proteolytic possibility, probiotic function and antibiotic resistance, but especially because of their decarboxylation abilities. Bacteria contain decarboxylation enzymes, which are able to decarboxylized free amino acid, which rising at proteolysis during process of manufacturing and cheese ripening. Biogenic amines are the result of proteolytic activity. Biogenic amines occur practically in all foodstuffs as a common product of metabolic processes. BA are mainly presented in fermented food (cheeses), where rice just microbial action. Typical representatives of biogenic amines, which occurs in double moulded cheeses (Sedlčanský Vltavín, Bresse bleu) and in blue cheeses (Bleu des Causses, Bleu d'Auvergne) are cadaverine, putrescine, tyramine a 2 fenylethylamine and in much smaller amount histamine, spermidine and spermine too. On assessment concentration of BA is used high pressure liquid chromatography with reverse phase (RP HPLC) with utilizing simple direct derivatization with dansyl chloride and detection by UV VIS detector.
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Analýza stárnutí vybraných materiálů stokových sítí / Analysis of ageing of selected materials used in sewage systems

Horák, Marek Unknown Date (has links)
The doctoral thesis deals with analysis of the ageing of concrete and reinforced concrete pipes in sewage systems. The ageing of the sewage system is caused by several reasons, for example material abrasion, chemical and biological corrosion and subsequent static overload sewer construction. One of the common causes of degradation of sewage systems made from materials bonded with cement sealant is biogenic sulphate corrosion. Due to the corrosion the degradation of the pipe walls accelerates, particularly in upper part of the pipe and reduces planned lifetime of the sewage system. There is proposed new ageing analysis monitoring method for observation and evaluation of the loss of thickness of concrete and reinforced concrete pipes, which is caused by biogenic sulphate corrosion. Residual lifetime is calculated from the expected corrosion rate, it`s the loss of wall thickness on the monitored section of the sewer system. There is designed the monitoring system of the loss of wall thickness on the sewage system for practical application of the measurement procedure, which is administrated in cooperation with the BVK, a. s. The thesis uses existing knowledge regarding this subject. We use this information for better understanding of the process of the loss of wall thickness in sewage systems in real time and the posibility to correct and in-time implementation of appropriate operational measures. This should cause the limitation of the degradation process of piping material while extended service life and safe operation in sewage systems within the required time period. Based on the methodology is proposed to determine the residual life of the sewage system and maintenance and rehabilitation can be done more effectively. There is needed to be noted that only long-term monitoring period can bring a better overview of the technical condition of sewage systems in time and thus better and more effective maintenance and rehabilitation, which is related to the effective u

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