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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.
1

Desenvolvimento e validação de um método analítico para detecção de carbofurano e 3-hidroxicarbofurano em matrizes biológicas com finalidade forense / Development and validation of analytical methodology to detect carbofuran and 3- hydroxy- carbofuran in biological matrices for forensic purposes

Gonçalves Junior, Vagner 27 November 2015 (has links)
Os praguicidas podem ser responsáveis por intoxicações exógenas intencionais ou não intencionais, tanto em seres humanos como em animais, em virtude de sua ampla toxicidade e fácil obtenção do produto, nem sempre por vias legais. O carbofurano é um praguicida carbamato amplamente utilizado no Brasil, como inseticida e nematicida, para o controle de pragas agrícolas; é comercializado na forma de grânulos, vulgarmente conhecido como “chumbinho”. Esse praguicida em animais superiores inibe a enzima acetilcolinesterase, promovendo efeitos tóxicos que podem levar a óbito. Considerando que o carbofurano poderia estar implicado com quadros intoxicações exógenas de animais, no presente estudo se propôs desenvolver e validar um método analítico para detectar e/ou quantificar esse praguicida e seu metabólito, 3-hiroxicarbofurano, em matrizes biológicas de diferentes espécies animais por cromatografia líquida de alta eficiência com detector de arranjo de diodos (CLAE-DAD), a fim de utilizá-lo no Laboratório de Diagnóstico Toxicológico (LADTOX) do Departamento de Patologia da Faculdade de Medicina Veterinária e Zootecnia (FMVZ) da Universidade de São Paulo (USP). Para desenvolver esse método foram utilizadas amostras biológicas proveniente de fragmentos de, no mínimo, seis animais diferentes, de espécies distintas (cão, gato, porco, boi, rato, camundongo e ave), isentas de suspeita de intoxicação. Realizou-se a fortificação dessas amostras biológicas, previamente homogeneizadas, com soluções contendo o praguicida e seu metabolito, 3-hidroxicarbofurano, em 6 níveis de fortificação que variaram de 6,25 a 100 µg/mL. Avaliaram-se os seguintes parâmetros para validação do método: seletividade, efeito matriz, precisão, exatidão, curva de calibração e efeito residual, limite de detecção (LD) e limite inferior de quantificação (LIQ). Para estabelecer a seletividade do método, verificou-se as respostas de picos interferentes próximo ao tempo de retenção dos analitos, as quais foram inferiores a 20% da resposta do analito nas amostras do LIQ. Quanto ao efeito matriz, não houve interferência relevante entre as matrizes analisadas. Em relação a precisão e exatidão do método, foi possível observar que o coeficiente de variação (CV) e o erro padrão relativo (EPR) não excederam ao limite máximo de 15%. Considerando a curva de calibração, o coeficiente de correlação (r2) apresentou valores iguais ou superiores que 0,99 nas diferentes matrizes para o carbofurano, enquanto para o 3-hidroxicarbofurano duas matrizes (fígado e conteúdo estomacal) apresentaram o valor de 0,98 e as demais superior a 0,99. A extração líquido-líquido forneceu valores de recuperação entre 74,29 a 100,1% para o carbofurano e entre 64,72 a 100,61% para o 3-hidroxicarbofurano, sendo o LIQ de 6,25 µg/mL. Conclui-se que o método se mostrou adequado para identificar e quantificar o carbofurano e seu metabólito em amostras biológicas, apresentando sensibilidade e seletividade adequadas, e os parâmetros de validação encontram-se de acordo com os limites sugeridos para validação de métodos bioanaliticos, sendo, assim, implantado no LADTOX / Pesticides are responsible for intentional or unintentional exogenous poisoning, in both humans and animals, because of their broad toxicity and prompt availability, not always legally. Carbofuran is a carbamate pesticide widely used in Brazil as an insecticide and nematicide for the control of agricultural pests. It is marketed in the form of beads, commonly known as "pellet". This pesticide inhibits acetylcholinesterase enzyme on higher animals, promoting toxic effects, which can lead to death. Considering that carbofuran could be implicated in cases of exogenous poisoning of animals, in the present study we aimed to develop and validate an analytical method for detecting and/or quantifying this pesticide and its metabolite, 3-hiroxicarbofuran, in biological matrices of different animal species by high performance liquid chromatography with diode array detector (HPLC-DAD) in order to use it in the Toxicology Diagnostics Laboratory (LADTOX) of the Department of Pathology, Faculty of Veterinary Medicine and Animal Science (FMVZ), University of São Paulo (USP). To develop this method biological samples obtained from fragments of at least six different animals of different species (dog, cat, pig, ox, rat, mouse and bird), free from suspicion of poisoning. Biological samples were fortified with previously homogenized solutions containing the pesticide and its metabolite, 3-hidroxicarbofurano, in 6 fortification levels ranging from 6.25 to 100 µg/mL We evaluated the following parameters for method validation: selectivity, matrix effects, precision, accuracy, calibration curve and residual effect, limit of detection (LOD) and lower limit of quantitation (LLQ). To establish selectivity of the method, we verified the responses of interfering peaks near the retention times of analytes, which were less than 20% of the analyte response in LLQ samples. As to matrix effects, there was no significant interference between the matrices analyzed. Regarding the precision and accuracy of the method, it was observed that the coefficient of variation (CV) and the relative standard error (RSE) did not exceed the ceiling of 15%. In regard to the calibration curve, the correlation coefficient (r2) presented values that equal or exceed 0.99 in different arrays to carbofuran, while for the 3-hidroxicarbofuran two arrays - liver and stomach contents - had a value of 0.98 while the remaining matrices 0,99. The liquid-liquid extraction recovery values varied between 74.29 to 100.1% for carbofuran and between 64.72 to 100.61% for 3-hidroxicarbofuran, and LOQ of 6.25 µg/ml. We concluded that the method was adequate to identify and quantify carbofuran and its metabolite in biological samples, with adequate sensitivity and selectivity, and the validation parameters are in accordance to the suggested limits for validation of bioanalytical methods, and, thus implanted in LADTOX
2

Desenvolvimento e validação de um método analítico para detecção de carbofurano e 3-hidroxicarbofurano em matrizes biológicas com finalidade forense / Development and validation of analytical methodology to detect carbofuran and 3- hydroxy- carbofuran in biological matrices for forensic purposes

Vagner Gonçalves Junior 27 November 2015 (has links)
Os praguicidas podem ser responsáveis por intoxicações exógenas intencionais ou não intencionais, tanto em seres humanos como em animais, em virtude de sua ampla toxicidade e fácil obtenção do produto, nem sempre por vias legais. O carbofurano é um praguicida carbamato amplamente utilizado no Brasil, como inseticida e nematicida, para o controle de pragas agrícolas; é comercializado na forma de grânulos, vulgarmente conhecido como “chumbinho”. Esse praguicida em animais superiores inibe a enzima acetilcolinesterase, promovendo efeitos tóxicos que podem levar a óbito. Considerando que o carbofurano poderia estar implicado com quadros intoxicações exógenas de animais, no presente estudo se propôs desenvolver e validar um método analítico para detectar e/ou quantificar esse praguicida e seu metabólito, 3-hiroxicarbofurano, em matrizes biológicas de diferentes espécies animais por cromatografia líquida de alta eficiência com detector de arranjo de diodos (CLAE-DAD), a fim de utilizá-lo no Laboratório de Diagnóstico Toxicológico (LADTOX) do Departamento de Patologia da Faculdade de Medicina Veterinária e Zootecnia (FMVZ) da Universidade de São Paulo (USP). Para desenvolver esse método foram utilizadas amostras biológicas proveniente de fragmentos de, no mínimo, seis animais diferentes, de espécies distintas (cão, gato, porco, boi, rato, camundongo e ave), isentas de suspeita de intoxicação. Realizou-se a fortificação dessas amostras biológicas, previamente homogeneizadas, com soluções contendo o praguicida e seu metabolito, 3-hidroxicarbofurano, em 6 níveis de fortificação que variaram de 6,25 a 100 µg/mL. Avaliaram-se os seguintes parâmetros para validação do método: seletividade, efeito matriz, precisão, exatidão, curva de calibração e efeito residual, limite de detecção (LD) e limite inferior de quantificação (LIQ). Para estabelecer a seletividade do método, verificou-se as respostas de picos interferentes próximo ao tempo de retenção dos analitos, as quais foram inferiores a 20% da resposta do analito nas amostras do LIQ. Quanto ao efeito matriz, não houve interferência relevante entre as matrizes analisadas. Em relação a precisão e exatidão do método, foi possível observar que o coeficiente de variação (CV) e o erro padrão relativo (EPR) não excederam ao limite máximo de 15%. Considerando a curva de calibração, o coeficiente de correlação (r2) apresentou valores iguais ou superiores que 0,99 nas diferentes matrizes para o carbofurano, enquanto para o 3-hidroxicarbofurano duas matrizes (fígado e conteúdo estomacal) apresentaram o valor de 0,98 e as demais superior a 0,99. A extração líquido-líquido forneceu valores de recuperação entre 74,29 a 100,1% para o carbofurano e entre 64,72 a 100,61% para o 3-hidroxicarbofurano, sendo o LIQ de 6,25 µg/mL. Conclui-se que o método se mostrou adequado para identificar e quantificar o carbofurano e seu metabólito em amostras biológicas, apresentando sensibilidade e seletividade adequadas, e os parâmetros de validação encontram-se de acordo com os limites sugeridos para validação de métodos bioanaliticos, sendo, assim, implantado no LADTOX / Pesticides are responsible for intentional or unintentional exogenous poisoning, in both humans and animals, because of their broad toxicity and prompt availability, not always legally. Carbofuran is a carbamate pesticide widely used in Brazil as an insecticide and nematicide for the control of agricultural pests. It is marketed in the form of beads, commonly known as "pellet". This pesticide inhibits acetylcholinesterase enzyme on higher animals, promoting toxic effects, which can lead to death. Considering that carbofuran could be implicated in cases of exogenous poisoning of animals, in the present study we aimed to develop and validate an analytical method for detecting and/or quantifying this pesticide and its metabolite, 3-hiroxicarbofuran, in biological matrices of different animal species by high performance liquid chromatography with diode array detector (HPLC-DAD) in order to use it in the Toxicology Diagnostics Laboratory (LADTOX) of the Department of Pathology, Faculty of Veterinary Medicine and Animal Science (FMVZ), University of São Paulo (USP). To develop this method biological samples obtained from fragments of at least six different animals of different species (dog, cat, pig, ox, rat, mouse and bird), free from suspicion of poisoning. Biological samples were fortified with previously homogenized solutions containing the pesticide and its metabolite, 3-hidroxicarbofurano, in 6 fortification levels ranging from 6.25 to 100 µg/mL We evaluated the following parameters for method validation: selectivity, matrix effects, precision, accuracy, calibration curve and residual effect, limit of detection (LOD) and lower limit of quantitation (LLQ). To establish selectivity of the method, we verified the responses of interfering peaks near the retention times of analytes, which were less than 20% of the analyte response in LLQ samples. As to matrix effects, there was no significant interference between the matrices analyzed. Regarding the precision and accuracy of the method, it was observed that the coefficient of variation (CV) and the relative standard error (RSE) did not exceed the ceiling of 15%. In regard to the calibration curve, the correlation coefficient (r2) presented values that equal or exceed 0.99 in different arrays to carbofuran, while for the 3-hidroxicarbofuran two arrays - liver and stomach contents - had a value of 0.98 while the remaining matrices 0,99. The liquid-liquid extraction recovery values varied between 74.29 to 100.1% for carbofuran and between 64.72 to 100.61% for 3-hidroxicarbofuran, and LOQ of 6.25 µg/ml. We concluded that the method was adequate to identify and quantify carbofuran and its metabolite in biological samples, with adequate sensitivity and selectivity, and the validation parameters are in accordance to the suggested limits for validation of bioanalytical methods, and, thus implanted in LADTOX
3

Biological Imaging with a Near-Field Optical Setup.

Denyer, Morgan C.T., Micheletto, R., Nakajima, K., Hara, M., Okazaki, S. January 2003 (has links)
No / Noncontact scanning near-field optical microscope (SNOM) systems can be used to optically resolve samples in atmospheric conditions at theoretical resolutions comparable to those of transmission electron microscope and atomic force microscope systems. SNOM systems are also increasingly used to image biological samples. In this study we custom built a SNOM system with the aim of further demonstrating the potential applications of near-field optical examination of biological material. In this study we were able to image both fixed whole-cell samples in air and liquid environments and live whole-cell samples in liquids. The images acquired were of a relatively low resolution, but this work has shown that SNOM systems can be used to monitor the dynamics of living cells at subnanometric resolutions in the z axis and for fluorescent imaging of whole cells in a liquid medium.
4

Novel strategies in near infrared spectroscopy (NIRS) and multivariate analysis (MVA) for detecting and profiling pathogens and diseases of agricultural importance.

Santos Rivera, Johjan Mariana 13 May 2022 (has links)
The time required for the identification of pathogens is an important determinant of infection-related mortality rates and disease spread for species of relevance in agriculture. Conventional identification methods require a processing time of at least one to twenty days. Therefore, inaccurate empirical treatments are often provided while awaiting further identification, such that most cases progress with further aggravation of symptoms, contamination of other animals or plants, generating economic loss from decreased yield, and increased mitigation costs. Thus, there is a need for innovative, non-destructive, and rapid analytical techniques that provide reagent-free, portable, reliable, and holistic approaches to detect diseases in real-time. Vibrational spectroscopy techniques have shown the capacity to provide relevant information for disease detection. In near infrared spectroscopy (NIRS), the absorbance from a sample is measured across several hundred wavelengths in the near infrared band (750-2500 nm) and is directly influenced by the number and type of chemical bonds present. In order to make NIRS an effective tool for field-based studies, a simplified procedure is needed such that NIRS can be used in minimally processed samples found in situ. Here, experiments involving the agricultural important bovine herpesvirus-1 (BoHV-1), bovine respiratory syncytial virus (BRSV), Mannheimia haemolytica (MH), Xanthomonas citri pv. malvacearum (Xcm) and Rhizoctonia solani (Rs) were carried out to determine if biological spectral signatures can be differentiated between samples from two classes (i.e., healthy vs. sick, control sample vs. test sample). The specific objectives were to (1) create a spectral library for each evaluated pathogen and disease, (2) identify and establish the characteristic NIR spectral signatures and trends by aquaphotomics and chemometrics-based MVA methods, (3) generate and evaluate models for discriminating representative spectra, (4) provide new biochemical information by the correlation of the results with pathogen development and disease states in living systems, and (5) support the groundwork for a portable, fast, non-destructive, and accurate diagnostic tool capable of reducing the existing time necessary for pathogen and disease detection.
5

Nouvelles stratégies d'analyses rapides d'acides nucléiques : étude et développement de dispositifs de prélèvements biologiques à des fins d'identification par empreinte génétique. / New strategies for rapid nucleic acid analysis : Studies and development of biological collecting tools for DNA identification

Hubac, Sylvain 09 June 2017 (has links)
La criminalistique peut être définie comme l’application de procédés techniques aux investigations judiciaires permettant l’étude scientifique des traces et des indices retrouvés sur les scènes de crime.Depuis la découverte de l’empreinte génétique par Sir Alec Jeffreys en 1984, le monde judiciaire s’est profondément ancré dans l’ère de l’ADN en raison d’évolutions technologiques successives dans le domaine de la biologie moléculaire et ses applications en criminalistique. Le besoin de réponse instantanée est omniprésent dans les esprits. La mise en œuvre de techniques d’analyses simples, sensibles, fiables et permettant d’obtenir des résultats dans les plus brefs délais sont les clés du succès.Au cours des processus techniques, la collecte du matériel biologique, et donc de l’ADN au sein de la trace, constitue une étape incontournable et cruciale qui va conditionner la réussite des analyses. Ce travail de recherche a donc consisté à développer des solutions performantes de prélèvements de matériels biologiques soit en détournant de leur fonction initiale des solutions existantes soit en développant des solutions simples mais innovantes combinant les avantages des solutions existantes. Ces travaux ont permis de donner naissance au micro-écouvillon GendSAG. Les potentialités de GendSAG permettent de proposer une solution alternative aux solutions commerciales de systèmes intégrés d’analyses rapide d’ADN. Cette solution alternative d’analyse rapide et haut débit de l’ADN mise en œuvre dans un laboratoire mobile au plus près de la scène de crime répond non seulement à la grande majorité des avantages des systèmes intégrés mais également à toutes leurs limitations. / Forensic sciences can be defined as the used of technical processes to judicial investigations allowing the scientific study of traces and evidences found on crime scenes.Since the discovery of DNA fingerprinting by Sir Alec Jeffreys in 1984, the legal world has become deeply rooted in the DNA by successive technological developments in molecular biology and its applications in forensic. The need for instant response is omnipresent in the minds. The key to success is the implementation of simple, sensitive, reliable analytical techniques that enable results to be achieved in the shortest possible time.During these technical processes, the collection of biological samples, is an unavoidable and a crucial step that will condition the analysis success rate. This study consisted in developing efficient biological collecting solutions either by diverting from their original function the existing solutions or by developing simple but innovative solutions combining the advantages of the existing solutions. This allowed developing the micro-swab GendSAG. The potentialities of GendSAG make it possible to propose an alternative solution to the commercial rapid DNA analysis integrated systems. This rapid, cost effective and high-throughput DNA analysis solution performed in a dedicated mobile laboratory directly into the crime scene enables the large majority of the rapid DNA analysis integrated systems benefits and also all of their limitations.
6

Ultrastructural and Histochemical Characterization of the Zebra Mussel Adhesive Apparatus

Farsad, Nikrooz 06 April 2010 (has links)
Since their accidental introduction into the Great Lakes in mid- to late-1980s, the freshwater zebra mussels, Dreissena polymorpha, have colonized most lakes and waterways across eastern North America. Their rapid spread is partly attributed to their ability to tenaciously attach to hard substrates via an adhesive apparatus called the byssus, resulting in serious environmental and economic impacts. A detailed ultrastructural study of the bysuss revealed a 10 nm adhesive layer at the attachment interface. Distributions of the main adhesive amino acid, 3,4-dihydroxyphenylalanine (DOPA), and its oxidizing (cross-linking) enzyme, catechol oxidase, were determined histochemically. It was found that, upon aging, DOPA levels remained high in the portion of the byssus closest to the interface, consistent with an adhesive role. In contrast, reduced levels of DOPA corresponded well with high levels of catechol oxidase in the load-bearing component of the byssus, presumably forming cross-links and increasing the cohesive strength.
7

Ultrastructural and Histochemical Characterization of the Zebra Mussel Adhesive Apparatus

Farsad, Nikrooz 06 April 2010 (has links)
Since their accidental introduction into the Great Lakes in mid- to late-1980s, the freshwater zebra mussels, Dreissena polymorpha, have colonized most lakes and waterways across eastern North America. Their rapid spread is partly attributed to their ability to tenaciously attach to hard substrates via an adhesive apparatus called the byssus, resulting in serious environmental and economic impacts. A detailed ultrastructural study of the bysuss revealed a 10 nm adhesive layer at the attachment interface. Distributions of the main adhesive amino acid, 3,4-dihydroxyphenylalanine (DOPA), and its oxidizing (cross-linking) enzyme, catechol oxidase, were determined histochemically. It was found that, upon aging, DOPA levels remained high in the portion of the byssus closest to the interface, consistent with an adhesive role. In contrast, reduced levels of DOPA corresponded well with high levels of catechol oxidase in the load-bearing component of the byssus, presumably forming cross-links and increasing the cohesive strength.

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