The food safety and human diagnostics markets are in need of faster working, reliable, sensitive, specific, low cost bioassays and biosensors for bacterial detection. This thesis reports the use of P22 bacteriophage tailspike proteins (TSP) immobilized on silanized silicon surfaces, roughened at a nano-scale, for specific capture and detection of Salmonella. Towards developing TSP biosensors, TSP immobilization characteristics were studied, and methods to improve bacterial capture were explored. Atomic force microscopy was used to count TSP immobilized on gold thin-films. Surface density counts are dependent on the immobilization scheme used. TSP immobilized on flat silicon (Si), silanized with 3-aminopropyltriethoxysilane and activated with glutaraldehyde, showed half the bacterial capture of gold thin-films. To improve bacterial capture, roughened mountain-shaped ridge-covered silicon (MSRCS) surfaces were coated with TSP and tested. Measurements of their bacterial surface density show that such MSRCS surfaces can produce bacterial capture close to or better than TSP-coated gold thin-films. / Biomedical Engineering

No description available.

Mining has negative impacts on the environment, and is one of the main contributors to environmental pollution. This holds a potential hazard for ecosystems surrounding mining areas and also for public health in the surrounding communities. There is therefore a need for ecotoxicological research in order to assess these possible risks and find ways to minimize the harmful effects. One way in which to assess soil vitality are soil enzymes which are produced by plants and microorganisms and will therefore be more abundant in healthy soils. Earthworms have been proven to be useful bioindicators for metal contamination of soil, as they are able to accumulate metals from their environment into their body tissue. The aim of this study was to use earthworm bioassays, neutral red retention time analysis (NRRt), enzymatic analysis and RAPD-PCR to determine the effect of mining activity on the environment. This was done by assessing the ecotoxicity of tailings collected from three different mines, viz. gold-, opencast chrome- and coal mines. The metals chosen for analyses included four (Cr, Co, Ni and Pb) of the seven (Cd, Cr, Ni, Pb, Zn, Cu, Co) environmentally important trace elements as described for South African soils. Arsenic was also chosen since it is associated with gold mine tailings. Tailings and soil were collected from three sites at each of the mines which included unrehabilitated (TDF-U) and rehabilitated (TDF-R) substrates from tailings disposal facilities (TDFs) and reference soils (RS) in close proximity to TDFs. The physical and chemical properties of these different substrates were determined in terms of pH, particle size as well as metal contents. In addition to this, they were analysed for microbial community function by means of enzymatic activity, which has been proven to be useful in evaluating contamination of soil. The enzymes analysed in this study included dehydrogenase, ßglucosidase, acid phosphatase, alkaline phosphatase and urease. Earthworms (Eisenia andrei) were exposed to different material for 28 days during which their biomass, reproduction, mortality and lysosomal membrane stability were monitored weekly. Hereafter, they were removed from the material while the cocoons were left behind for a further 56 days. The hatched and unhatched cocoons as well as the juvenile worms were then counted to determine reproduction patterns in the materials. Metal concentrations in the substrates and earthworm body tissues were compared to selected benchmarks. Results indicated that when comparing the different materials from each mine, enzymatic activity proved to be a very sensitive parameter. Enzymatic activity showed significant differences (p < 0.05) between RS, TDF-R and TDF-U materials. Biomass was not a sensitive parameter (p > 0.05) for the worms exposed to the gold and chrome mine tailings, but it was a sensitive parameter (p < 0.05) for the coal mine exposed earthworms, showing early differences between the worms from the different sites (RS, TDF-R and TDF-U). The NRR-t assay was very sensitive (p < 0.05), indicating clear differences between the worms from each investigated site. In terms of reproduction, the production of cocoons showed clear differences (p < 0.05) between the different sites and could therefore be considered a sensitive parameter. Hatching success however, was not a sensitive parameter. The reason being that there were so little cocoons produced that it is not possible to determine the correct percentage of juvenile worms hatching from, for example, only one or two cocoons. Mortality was also not a sensitive endpoint as it was only observed in the coal mine material. RAPD - PCR results indicated genetic differences between earthworms exposed to the control- and the tailings materials, indicating either DNA alterations due to possible genotoxic effects, or genetic variation between individuals of the same species. Since mine waste materials often contain complex mixtures of metals that might be toxic on their own or in combination with other factors, it is difficult to attribute any observed genotoxic effect to any of the specific metals. / Thesis (MSc (Environmental Sciences))--North-West University, Potchefstroom Campus, 2012.

Mining has negative impacts on the environment, and is one of the main contributors to environmental pollution. This holds a potential hazard for ecosystems surrounding mining areas and also for public health in the surrounding communities. There is therefore a need for ecotoxicological research in order to assess these possible risks and find ways to minimize the harmful effects. One way in which to assess soil vitality are soil enzymes which are produced by plants and microorganisms and will therefore be more abundant in healthy soils. Earthworms have been proven to be useful bioindicators for metal contamination of soil, as they are able to accumulate metals from their environment into their body tissue. The aim of this study was to use earthworm bioassays, neutral red retention time analysis (NRRt), enzymatic analysis and RAPD-PCR to determine the effect of mining activity on the environment. This was done by assessing the ecotoxicity of tailings collected from three different mines, viz. gold-, opencast chrome- and coal mines. The metals chosen for analyses included four (Cr, Co, Ni and Pb) of the seven (Cd, Cr, Ni, Pb, Zn, Cu, Co) environmentally important trace elements as described for South African soils. Arsenic was also chosen since it is associated with gold mine tailings. Tailings and soil were collected from three sites at each of the mines which included unrehabilitated (TDF-U) and rehabilitated (TDF-R) substrates from tailings disposal facilities (TDFs) and reference soils (RS) in close proximity to TDFs. The physical and chemical properties of these different substrates were determined in terms of pH, particle size as well as metal contents. In addition to this, they were analysed for microbial community function by means of enzymatic activity, which has been proven to be useful in evaluating contamination of soil. The enzymes analysed in this study included dehydrogenase, ßglucosidase, acid phosphatase, alkaline phosphatase and urease. Earthworms (Eisenia andrei) were exposed to different material for 28 days during which their biomass, reproduction, mortality and lysosomal membrane stability were monitored weekly. Hereafter, they were removed from the material while the cocoons were left behind for a further 56 days. The hatched and unhatched cocoons as well as the juvenile worms were then counted to determine reproduction patterns in the materials. Metal concentrations in the substrates and earthworm body tissues were compared to selected benchmarks. Results indicated that when comparing the different materials from each mine, enzymatic activity proved to be a very sensitive parameter. Enzymatic activity showed significant differences (p < 0.05) between RS, TDF-R and TDF-U materials. Biomass was not a sensitive parameter (p > 0.05) for the worms exposed to the gold and chrome mine tailings, but it was a sensitive parameter (p < 0.05) for the coal mine exposed earthworms, showing early differences between the worms from the different sites (RS, TDF-R and TDF-U). The NRR-t assay was very sensitive (p < 0.05), indicating clear differences between the worms from each investigated site. In terms of reproduction, the production of cocoons showed clear differences (p < 0.05) between the different sites and could therefore be considered a sensitive parameter. Hatching success however, was not a sensitive parameter. The reason being that there were so little cocoons produced that it is not possible to determine the correct percentage of juvenile worms hatching from, for example, only one or two cocoons. Mortality was also not a sensitive endpoint as it was only observed in the coal mine material. RAPD - PCR results indicated genetic differences between earthworms exposed to the control- and the tailings materials, indicating either DNA alterations due to possible genotoxic effects, or genetic variation between individuals of the same species. Since mine waste materials often contain complex mixtures of metals that might be toxic on their own or in combination with other factors, it is difficult to attribute any observed genotoxic effect to any of the specific metals. / Thesis (MSc (Environmental Sciences))--North-West University, Potchefstroom Campus, 2012.

The presence of complex mixtures of compounds in ambient air, many of which are either unknown or uncharacterised makes an assessment of risk associated with these exposures problematic. Bioanalytical methods can provide an integrative assessment of complex mixture potency for specific mechanisms of toxicity within these contexts. The aim of this study was to evaluate the suitability of monitoring ambient air exposures as sampled by (polyurethane foam) PUF passive air samplers (PAS) using effect based techniques (bioanalytical methods). Passive samplers have the advantage of offering a low-tech inexpensive monitoring strategy which can thereby increase sampling capacity across a broader range of scenarios simultaneously. One challenge posed by the application of passive samplers in particular for these assessments has been the expression of potency estimates in relatively non-comparable terms specific to a given dose of the sampler or for a specific deployment period. The project was therefore designed in order to address these aims and previously identified challenges by investigating the applicability of these techniques for: monitoring in both indoor and outdoor air, the determination of seasonal exposure gradients; the determination of exposure gradients in different locations (urban capitals, regional centres, background); and the application of in-situ calibration to provide comparable effect measurements in terms of equivalent reference compound air concentrations. Air sampled using PUF PAS was monitored for its capacity to induce biological responses which are mechanistically relevant to critical health endpoints in these scenarios. The mechanisms assessed included genotoxicity (DNA damage – umuC assay), Aryl hydrocarbon receptor (AhR) activity (CAFLUX assay), and estrogenicity (ESCREEN assay). The findings from this effect based monitoring revealed that the level of biological response measured changes with the exposure scenario (indoor vs. outdoor; summer vs. winter; urban capital cities vs. background locations). Estrogenicity for example assessed as estradiol equivalent air concentrations (E Eq BIO) averaged 54 pg.m-3 (1.5 - 185 pg.m-3) in indoor air, while samples from ambient air were found to be not estrogenic. Total aryl hydrocarbon receptor (AhR) activity assessed as 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalent air concentrations (TCDD Eq BIO) averaged 4.1 pg.m-3 (1.3 – 7.2 pg.m-3) in indoor air while samples from ambient air averaged 15 pg.m-3 (1.5 – 46 pg.m-3)in summer and 53 pg.m-3 (2.2 – 251 pg.m-3) in winter. The relationship for both direct (-S9) and indirect (+S9) acting genotoxicity and AhR activity were found to be relatively consistent with respect to both season (elevated in winter) and location (elevated in urban capital cities). Overall suitable techniques were developed for combining passive sampling with multiple end-point toxicity testing and it was demonstrated that these techniques may be applied across different exposure scenarios. During the course of this method development and interpretation process a range of limitations were identified relating to: the use and application of effect based techniques to monitor environmental samples; the use of passive samplers within this context specifically; and also with the application of in-situ calibration techniques to passive samplers to improve the comparability of these assessments.

Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 4 uppsatser.

Made available in DSpace on 2014-06-11T19:32:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-10-17Bitstream added on 2014-06-13T20:24:14Z : No. of bitstreams: 1 barros_lss_dr_jabo.pdf: 442989 bytes, checksum: d2120f4be8555a47d673c616ab5f29e1 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Este trabalho foi delineado objetivando informações dos riscos dos abatedouros ao ambiente e à Saúde Pública. Foram analisadas, na chuva e na seca e em sete abatedouros avícolas e sete suinícolas, águas de: abastecimento, de diferentes pontos do fluxograma de abate, dos afluentes e efluentes dos sistemas de tratamento e de três pontos do corpo receptor. Nas investigações físicas e químicas determinaram-se: temperatura, pH, cloro residual livre, DBO, DQO, NO3, NO2, nitrogênio, K, Fe, Na, Ca, Mg, Mn, Cd, Co, Zn, Pb, Ni, Co e Cr, além de bioensaios com Daphnia magna nos efluentes. As mensurações microbiológicas concentraram-se nos indicadores fecais e na Salmonella. O isolamento de Salmonella ocorreu na escaldadura (14,29%), depenagem (7,41%), pré-resfriamento (7,41%) e efluentes (7,41%), nos abatedouros avícolas, e na lavagem do ambiente (7,41%) e nos afluentes (7,41%), nos suinícolas. A escaldadura, a depenagem, a evisceração e as lavagens das carcaças e do ambiente, no abate avícola, e as lavagens das carcaças e do ambiente, no abate suinícola, foram os pontos mais impactantes. Três efluentes dos abatedouros avícolas e dois dos suinícolas apresentaram poder impactante. Testes demonstraram o Zn, Mn, Mg, Ni, Ca, Cd, Fe, Na e Cu, como os metais de menor correlação, e o Cr, Co e Pb, como os de maior correlação. / This work was done to obtain information about the risks of slaughterhouse on the environment and Public Health. It was analyzed, on rain and dryness and in seven poultry and swine slaughterhouses, water from: supply, different points of the slaughter flowchart, affluents and effluents of the treatment systems, and three points of the receiver structure. The chemical and physical investigations determinated: temperature, pH, free residual chlorine (FRC), BOD, COD, NO3-N, NO2-N, kjeldahl nitrogen, K, Fe, Na, Ca, Mg, Mn, Cd, Co, Zn, Pb, Ni, Co and Cr. Bioassays with Daphnia magna were done in the effluents. The microbiological determinations were concentrated in the fecal microrganisms and in the Salmonella. The results showed the Salmonella isolation in the scalding (14,29%), deplume (7,41%), pre-chiller (7,41%) and effluent (7,41%), in the avian slaughterhouse, and in the environment wash (7,41%) and affluent (7,41%), in the swine slaughterhouse. The scalding, deplume, evisceration, carcass and environment wash, in the avian slaughter, and the carcass and environment wash, in the swine slaughter, were the points with the highest impact. Three effluents, from avian slaughterhouses, and two, of the swine slaughterhouses showed a strong power to impact. Tests demonstrated the Zn, Mn, Mg, Ni, Ca, Cd, Fe, Na and Cu, as the metal with the less correlation, and the Cr, Co and Pb, as the most.

Orientador: Ian Castro-Gamboa / Coorientador: Márcia Nasser Lopes / Banca: Silvia Noeli López / Banca: Renato Lajarim Carneiro / Resumo: No presente trabalho foram detectados e analisados os metabólitos secundários majoritários das espécies Jatropha multifida L. e J. gossypifolia L., fazendo uso de ferramentas quimiométricas de vanguarda, visando a otimização do processo de extração para, posteriormente, obter cromatogramas de fingerprint através da técnica acoplada CLAE-UV/DAD. Para a espécie J. gossypifolia L. a mistura 1 : 1 clorofórmio : isopropanol apresentou a melhor condição de extração enquanto para J. multifida L. a composição 2/3 : 1/6 : 1/6 de etanol : acetona : 1,4-dioxano foi a que obteve a melhor resposta. Os cromatogramas de fingerprint foram realizados fazendo uso de uma coluna monolítica C-18 (5 µm), como fase estacionária, enquanto a fase móvel para análise da espécie J. gossypifolia L. foi composta por água e uma mistura de solventes orgânicos, MeOH : ACN, na proporção (68 : 32), em gradiente exploratório de 5-100% de fase orgânica. Para a espécie J. gossypifolia L., as condições otimizadas foram: temperatura de coluna de 30 °C, fluxo em 2,0 mL·min-1 e o volume de injeção de 30 µL. Para J. multifida L. a fase móvel foi composta por água e uma mistura MeOH : ACN 1 : 1 em gradiente exploratório 5-100% de fase orgânica. A temperatura de coluna de 40 °C, o fluxo de 2,5 mL·min-1 e o volume de injeção foi de 30 µL. Foram realizados bioensaios in vitro, tais como a redução do reagente DPPH (ação antioxidante), inibição da polimerização da hematina bovina (ação antimalárica), inibição enzimática de acetilcolinesterase (doença de Alzheimer) e o ensaio da inibição do crescimento de fungos fitopatógenos. Nenhum dos extratos brutos avaliados, apresentou atividade significativa quando comparados com os padrões. Quanto à detecção dos metabólitos, a aplicação de métodos de desreplicação aos extratos permitiram a identificação de algumas classes... (Resumo completo, clicar acesso eletrônico baixo) / Abstract: The main goal of this research was to detect and analyze major secondary metabolites from Jatropha multifida L. and J. gossypifolia L. species, using state of art techniques in chemometrics aiming the optimization of the extraction process prior to the acquisition of the fingerprint chromatogram using HPLC-UV/DAD. The optimized extraction condition for Jatropha gossypifolia was the binary mixture 1:1 chloroform:isopropanol, while to Jatropha multifida L. the mixture was ternary consisting of 2/3:1/6:1/6 ethanol:acetone:1,4-dioxane. The fingerprint chromatograms were runned using an exploratory gradient consisting of 5-100% of organic solvent, using a C-18 (5 µm) column, as stationary phase, and then the mobile phase was optimized, through the use of chemometrics for each species. In the case of Jatropha gossypifolia L. the phase consisted in a mixture of 68:32 MeOH:ACN, under a column temperature of 30 oC, injection volume of 30 µL and a flow of 2.0 mL.min-1. For Jatropha multifida L. was 1:1 MeOH:ACN, under column temperature of 40 oC, flow of 2,5 mL.min-1 and an injection volume of 30 µL. Some in vitro bioassays were performed, such as, reduction of the reagent DPPH (antioxidant action), inhibition of polymerization of the haematin bovine (antimalarial), enzymatic inhibition of the acetylcholinesterase (Alzheimer's disease) and the assay of inhibition of the growth of phytopatogenic fungi. None of the crude extracts showed significant activities when compared to the used standards. The application of dereplication methods allowed the identification of some classes of compounds, already reported for Jatropha, such as terpenoids and flavonoids. The strategy developed to performed the dereplication, used an in silico approach through the matching and analysis of the spectrometric and spectroscopic data sets obtained using NMR and HPLC-HRMS(ESI)-MS2 with databases of high... (Complete abstract click electronic access below) / Mestre

Orientador: Luiz Augusto do Amaral / Banca: Roque Passos Piveli / Banca: Tânia Mara Baptista dos Santos / Banca: Jorge de Lucas Júnior / Banca: Joaquim Gonçalves Machado Neto / Resumo: Este trabalho foi delineado objetivando informações dos riscos dos abatedouros ao ambiente e à Saúde Pública. Foram analisadas, na chuva e na seca e em sete abatedouros avícolas e sete suinícolas, águas de: abastecimento, de diferentes pontos do fluxograma de abate, dos afluentes e efluentes dos sistemas de tratamento e de três pontos do corpo receptor. Nas investigações físicas e químicas determinaram-se: temperatura, pH, cloro residual livre, DBO, DQO, NO3, NO2, nitrogênio, K, Fe, Na, Ca, Mg, Mn, Cd, Co, Zn, Pb, Ni, Co e Cr, além de bioensaios com Daphnia magna nos efluentes. As mensurações microbiológicas concentraram-se nos indicadores fecais e na Salmonella. O isolamento de Salmonella ocorreu na escaldadura (14,29%), depenagem (7,41%), pré-resfriamento (7,41%) e efluentes (7,41%), nos abatedouros avícolas, e na lavagem do ambiente (7,41%) e nos afluentes (7,41%), nos suinícolas. A escaldadura, a depenagem, a evisceração e as lavagens das carcaças e do ambiente, no abate avícola, e as lavagens das carcaças e do ambiente, no abate suinícola, foram os pontos mais impactantes. Três efluentes dos abatedouros avícolas e dois dos suinícolas apresentaram poder impactante. Testes demonstraram o Zn, Mn, Mg, Ni, Ca, Cd, Fe, Na e Cu, como os metais de menor correlação, e o Cr, Co e Pb, como os de maior correlação. / Abstract: This work was done to obtain information about the risks of slaughterhouse on the environment and Public Health. It was analyzed, on rain and dryness and in seven poultry and swine slaughterhouses, water from: supply, different points of the slaughter flowchart, affluents and effluents of the treatment systems, and three points of the receiver structure. The chemical and physical investigations determinated: temperature, pH, free residual chlorine (FRC), BOD, COD, NO3-N, NO2-N, kjeldahl nitrogen, K, Fe, Na, Ca, Mg, Mn, Cd, Co, Zn, Pb, Ni, Co and Cr. Bioassays with Daphnia magna were done in the effluents. The microbiological determinations were concentrated in the fecal microrganisms and in the Salmonella. The results showed the Salmonella isolation in the scalding (14,29%), deplume (7,41%), pre-chiller (7,41%) and effluent (7,41%), in the avian slaughterhouse, and in the environment wash (7,41%) and affluent (7,41%), in the swine slaughterhouse. The scalding, deplume, evisceration, carcass and environment wash, in the avian slaughter, and the carcass and environment wash, in the swine slaughter, were the points with the highest impact. Three effluents, from avian slaughterhouses, and two, of the swine slaughterhouses showed a strong power to impact. Tests demonstrated the Zn, Mn, Mg, Ni, Ca, Cd, Fe, Na and Cu, as the metal with the less correlation, and the Cr, Co and Pb, as the most. / Doutor

Made available in DSpace on 2016-12-23T13:23:26Z (GMT). No. of bitstreams: 1 Fernanda Farias Duque.pdf: 807222 bytes, checksum: 0c1dd87b5f8f95ab1e7791bac3f4860c (MD5) Previous issue date: 2013-02-27 / A Achillea millefolium, conhecida como mil-folhas ou aquiléia, é uma planta da família Asteraceae e possui atividade como antibacteriana, antifúngica, antitumoral, cicatrizante, antioxidante e antiedematosa. O objetivo deste trabalho foi determinar o perfil cromatográfico e avaliar a atividade fungicida in vitro do extrato etanólico de A. millefolium sobre Colletotrichum gloeosporioides causador da antracnose em frutos de mamão. Partes da planta foram coletadas em dois meses diferentes e separadas em flores, folhas e ramos. Os bioensaios foram realizados com os extratos etanólicos secos, obtido por técnica de maceração e concentrado em evaporador rotativo sob pressão reduzida. Estes extratos foram submetidos a cromatografia preparativa em camada delgada (CCD) sendo obtidas cinco frações. Estas frações foram diluídas, separadamente, em 150&#956;L de DMSO e incorporada em BDA. Após solidificação do meio, um disco de 0,6cm de diâmetro com o fungo foi colocado no centro da placa de petri e incubado a 28 ± 2°C. Após crescimento avaliou-se o crescimento radial do micélio. O delineamento experimental utilizado foi análise fatorial e as médias foram comparadas pelo teste de Tukey a 5% de probabilidade. A atividade antifúngica foi evidenciada contra C. gloeosporioides sendo que as frações F4 e F5 de folha e flor coletadas em outubro tiveram a maior porcentagem de inibição do crescimento micelial. O perfil cromatográfico das frações do extrato foi realizado através de analises utilizando HPLC-DAD e GC-MS. Através das análises utilizando HPLC e GC da folha coletada em outubro foi possível detectar a presença de ácido cumárico, ácido ferúlico e rutina nas frações F4 e F5 / The Achillea millefolium, known as mil-folhas or aquilea, is a plant of the Asteraceae family and possesses activity as antibacterial, antifungal, antitumor, healing, antioxidant and antiedematosa. The aim of this study was to determine the elution profile and evaluate the in vitro antifungal activity of the ethanol extract of A. millefolium on Colletotrichum gloeosporioides causing anthracnose on papaya fruits. Parts of the plant were collected in two different months and separated into flowers, leaves and branches. Bioassays were performed with dry ethanolic extracts obtained by maceration technique and concentrated in a rotary evaporator under reduced pressure. These extracts were subjected to preparative thin layer chromatography (TLC) was obtained five fractions. These fractions were diluted separately in 150&#956;L of DMSO and incorporated in BDA. After solidification of the medium, a disc of 0.6 cm diameter with the fungus was placed in the center of a petri dish and incubated at 28 ± 2°C. After growth evaluated the radial growth of the mycelium. The experimental design was factorial analysis and the means were compared by Tukey test at 5% probability. The antifungal activity was observed against C. gloeosporioides whereas fractions F4 and F5 of leaf and flower collected in october had the highest percentage of mycelial growth inhibition. The chromatographic profile of the fractions of the extract was performed by analysis using HPLC-DAD and GC-MS. Through analysis using HPLC and GC leaf collected in october was possible to detect the presence of coumaric acid, ferulic acid and rutin in fractions F4 and F5