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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.
231

Lipid Residues Preserved in Sheltered Bedrock Features at Gila Cliff Dwellings National Monument, New Mexico

Buonasera, Tammy 31 October 2016 (has links)
Bedrock features represent various economic, social, and symbolic aspects of past societies, but have historically received little study, particularly in North America. Fortunately, new techniques for analyzing spatial configurations, use-wear, and organic residues are beginning to unlock more of the interpretive potential of these features. Though preliminary in nature, the present study contributes to this trend by documenting an application of lipid analysis to bedrock features in a dry rockshelter. Results of this initial application indicate that bedrock features in dry rockshelters may provide especially favorable conditions for the preservation and interpretation of ancient organic residues. Abundant lipids, comparable to concentrations present in some pottery sherds, were extracted from a bedrock grinding surface at Gila Cliff Dwellings National Monument and analyzed using gas chromatography-mass spectrometry. Though the lipids were highly oxidized, degradation products indicative of former unsaturated fatty acids were retained. Comparisons to experimentally aged residues, and absence of a known biomarker for maize, indicate that the bulk of the lipids preserved in the milling surface probably derive from processing an oily nut or seed resource, and not from processing maize. Substantially lower amounts of lipids were recovered from a small, blackened cupule. It is hypothesized that some portion of the lipids in the blackened cupule was deposited from condensed smoke of cooking and heating fires in the caves. Potential for the preservation of organic residues in similar sheltered bedrock contexts is discussed, and a practical method for sampling bedrock features in the field is described.
232

Application of gas chromatography and mass spectrometry for analysis of propolis from different geographic regions

Christov, Roumen January 2004 (has links)
Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.
233

Studium biodegradace PCB pomocí ligninolytických hub. / Study on biodegradation of PCBs by white-rot fungi.

Kožená, Lenka January 2010 (has links)
The biodegradation of Delor 103, a commercial mixture of PCB congeners, was studied with eight strains of white rot fungi in two nutritive media: in mineral nitrogen limited medium (so called Kirk medium) and in complex Malt- extract glucose medium. The most efficient biodegradation was observed with the fungus Pleurotus ostreatus, where 99% of PCB congener sum was degraded after 42 days in both media. Bjerkandera adusta was able to degrade 89% of PCB congener sum within 42 days in complex medium. Irpex lacteus removed 70% of PCB congener sum within 42 days in Kirk medium. Other white rot fungi showed lower biodegradation ability, degrading only low chlorinated biphenyls. Further, urgent toxicity of samples was monitored during the Delor 103 biodegradation. P. ostreatus proved to be the most suitable agens for PCB decontamination as a significant reduction of toxicity in comparison with controls was observed during the PCB degradation. In case of other fungi, no reduction of urgent toxicity was observed showing a disadvantage of their use for PCB biodegradation. Activities of ligninolitic enzymes during biodegradation were also studied. In both media laccase activity was detected in Dichomitus squalens, Pycnoporus cinnabarinus and Trametes versicolor cultures. Ligninperoxidase enzyme activity was...
234

Vliv požití ethanolu na tvorbu ethylesterů mastných kyselin pro účely průkaznosti zbytkového alkoholu v krvi / The Effect of Consumption of Ethanol on Formation of Fatty Acid Ethyl Esters for the Purposes of Detection of Residual Alcohol in Blood

Strachoňová, Jana January 2009 (has links)
Blood ethanol is a widely accepted marker for recent ethanol intake (within the last 4-6 h). However, the rapid elimination of ethanol from the body nearly always makes it impossible to assess ethanol ingestion beyond the most recent 6-8h. But serum fatty acid ethyl ester (FAEE) is detectable in the blood both when ethanol is presented and long after ethanol has been removed from the circulation. For this FAEE should be better marker for prior ethanol intake.
235

Neurotropní a antioxidační aktivita vybraných druhů jednoděložných alkaloidních rostlin. VIII. / Neurotropic and antioxidative activity of some selected species of monocotyledonous alkaloidal plants in vitro. VIII.

Breiterová, Kateřina January 2015 (has links)
Author: Kateřina Breiterová Title: Neurotropic and antioxidative activity of some selected species of monocotyledonous alkaloidal plants in vitro. VIII. Diploma thesis Charles Univerzity in Prague, Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Botany and Ecology 2015, 101 p. More than 50 % cases of dementia are nowadays caused byAlzheimer's disease (AD). AD is a progressive neurodegenerative disease and it causes gradual memory loss, disorientation and behavioral disorders which affect patient's social and occupational life. AD is characteristic by loss of neurons in some regions of brain - for example hippocampus and cortex. Ethiopathogenesis of this disease is not completely known - that is why the treatment is still just symptomatic. Formation of β-amyloid deposits in brain tissue plays an important role - it is a protein which creates extracellular plagues around neurites and causes their degeneration and death. Intracellular tangles are made up of the changed τ-protein. These tangles also cause death of the neuronal cell. The degeneration of neurons is supported by reactive oxygen radicals too. The another problem is a glutamatergic system disorder. This set of excitatory amino acids is important for correct long-term memory formation. Patients with AD suffer from...
236

Identification of Major Organic Constituents of Saffron Isolated by Solid Phase Extraction and Column Chromatography

Alsudairy, Ziad 31 July 2019 (has links)
Water extracts of saffron, a spice derived from the plant Crocus Sativus L. obtained from India and Iran, were analyzed by liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS). The components in the extracts were separated on four different solid phase extraction cartridges with four different solvents and by silica gel column. Analysis was done by GC-MS, LC-MS and UV-Vis spectroscopy. The extracts separated into three distinct bands (two bright yellow and one orange) on the silica gel column. Based on GC-MS, the extracted compounds show many structural similarities. Using both extraction techniques, several compounds were identified that were not previously reported to be in saffron. Picrocrocin, safranal, and crocins presence in the extracts were evidenced by absorbance bands at wavelengths of 250 nm, 310 nm and 440 nm, respectively, in their UV-Vis spectra. The LC-MS analysis revealed several high molecular weight compounds that were not observed by GC-MS.
237

O meio de cultura sólido diminui a exsudação de ácidos orgânicos em raízes de plantas expostas ao alumínio em relação à solução nutritiva? /

Silva, Marcela Paula. January 2019 (has links)
Orientador: Gustavo Habermann / Resumo: O alumínio (Al) é um dos componentes mais abundantes da crosta terrestre e é tóxico à maioria das plantas, sendo o seu primeiro sintoma de toxicidade a redução no crescimento radicular. Algumas plantas desenvolveram mecanismos para tolerar a presença do Al por meio da formação de complexos de ácidos orgânicos (AOs) com Al, internamente (no simplasto da folha ou das raízes) ou fora da raiz (apoplasto da raiz ou rizosfera). Neste trabalho, plantas de Titricum aestivum L. (Poaceae) (trigo) de cultivar sensível ao Al (ANAHUC75) e tolerante ao Al (JAC5) foram cultivados em diferentes concentrações de Al, variando o estado físico do meio, sendo estes sólido e líquido. Foram encontrados o ácido oxálico e succínico exsudados pelas raízes e acumulados no meio de cultura. Estes foram qualificados e quantificados por Cromatografia Gasosa por Espectrofotometria de Massas (GC-MS) e analisados por métodos estatísticos (ANOVA, teste de Kruskal-Wallis e PCA). Assim, foi possível verificar que o estado físico do meio de cultura gera diferenças significativas nas concentrações de exsudados pela raiz quando cultivadas nas mesmas concentrações de Al, visto que para o ácido succínico em ambas as cultivares e em todos os tratamentos e o ácido oxálico na cultivar tolerante apresentaram disparidade em relação aos teores exsudados. / Abstract: Aluminum (Al) is one of the most abundant elements of the Earth's crust and it is toxic to most plants, being the reduction of root growth its first toxicity symptom. Some plants have developed mechanisms to tolerate Al through the formation of organic acid complexes (AOs) with Al. This occurs internally (in the root or leaf symplast) or outside the root environment (root apoplast or even in the rhizosphere). Here, Titricum aestivum L. (Poaceae) (wheat) plants of an Al-sensitive cultivar (ANAHUC75) and an Al-tolerant cultivar (JAC5) were cultivated at different concentrations of Al, varying the physical state of the medium, being solid and liquid. Oxalic and succinic acid were exuded by the roots and accumulated in the culture medium. These were qualified and quantified by Mass Spectrophotometric Gas Chromatography (GC-MS) and analyzed by statistical methods (ANOVA, Kruskal-Wallis test and PCA). Thus, it was possible to verify that the physical state of the culture medium generates significant differences in the concentrations of root exudates when cultivated at the same Al concentrations, since for succinic acid in both cultivars and in all treatments and oxalic acid in tolerant cultivar presented disparity in relation to the exudate contents. / Mestre
238

Evaluation of 1H-NMR and GC/MS-based metabonomics for the assessment of liver and kidney toxicity / Bewertung von 1H-NMR und GC/MS-Metabonomics zur Erkennung von Leber- und Nierentoxizität

Sieber, Maximilian January 2009 (has links) (PDF)
For the assessment of metabonomics techniques for the early, non-invasive detection of toxicity, the nephrotoxins gentamicin (s.c. administration of 0, 60 and 120 mg/kg bw 2x daily for 8 days), ochratoxin A (p.o. administration of 0, 21, 70 and 210 µg/kg bw 5 days/week for 90 days) and aristolochic acid (p.o. administration of 0, 0.1, 1.0 and 10 mg/kg bw for 12 days) were administered to rats and urine samples were analyzed with 1H-NMR and GC/MS. Urine samples from the InnoMed PredTox project were analyzed as well, thereby focusing on 1H-NMR analysis and bile duct necrosis as histopathological endpoint. 1H-NMR analysis used water supression with the following protocol: 1 M phosphate buffer, D2O as shift lock reagent, D4-trimethylsilyl­propionic acid as chemical shift reference, noesygppr1d pulse sequence (Bruker). For multivariate data analysis, spectral intensity was binned into 0.04 ppm wide bins. GC/MS analysis of urine was carried out after protein precipitation with methanol, drying, derivatization with methoxyamine hydrochloride in pyridine and with methyl(trimethylsilyl)­trifluoroacetamide on a DB5-MS column using EI ionization. The chromatograms were prepared for multivariate data analysis using the R-program based peak picking and alignment software XCMS version 2.4.0. Principal component analysis (PCA) to detect and visualize time-point and dose-dependent differences between treated animals and controls and orthogonal projection to latent structures discriminant analysis (OPLS-DA) for identification of potential molecular markers of toxicity was carried out using SIMCA P+ 11.5 1H-NMR-based markers were identified and quantified with the Chenomx NMR Suite, GC/MS based markers were identified using the NIST Mass Spectral Database and by co-elution with authentic reference standards. PCA of urinary metabolite profiles was able to differentiate treated animals from controls at the same time as histopathology. An advantage over classical clinical chemistry parameters regarding sensitivity could be observed in some cases. Metabonomic analysis with GC/MS and 1H-NMR revealed alterations in the urinary profile of treated animals 1 day after start of treatment with gentamicin, correlating with changes in clinical chemistry parameters and histopathology. Decreased urinary excretion of citrate, 2-oxoglutarate, hippurate, trigonelline and 3-indoxylsulfate increased excretion of 5-oxoproline, lactate, alanine and glucose were observed. Ochratoxin A treatment caused decreased excretion of citrate, 2-oxoglutarate and hippurate and and increased excretion of glucose, myo-inositol, N,N-dimethylglycine, glycine, alanine and lactate as early as 2 weeks after start of treatment with 210µg OTA/kg bw, correlating with changes in clinical chemistry parameters and histopathology. Integration of histopathology scores increased confidence in the molecular markers discovered. Aristolochic acid treatment resulted in decreased urinary excretion of citrate, 2-oxoglutarate, hippurate and creatinine as well as increased excretion of 5-oxoproline, N,N-dimethylglycine, pseudouridine and uric acid. No alterations in clinical chemistry parameters or histopathology were noted.Decreased excretion of hippurate indicates alterations in the gut microflora, an effect that is expected as pharmacological action of the aminoglycoside antibiotic gentamicin and that can also be explained by the p.o. administration of xenobiotica. Decreased Krebs cycle intermediates (citrate and 2-oxoglutarate) and increased lactate is associated with altered energy metabolism. Increased pseudouridine excretion is associated with cell proliferation and was observed with aristolochic acid and ochratoxin A, for which proliferative processes were observed with histopathology. 5-oxoproline and N,N-dimethylglycine can be associated with oxidative stress. Glucose, a marker of renal damage in clinical chemistry, was observed for all three nephrotoxins studied. Single study analysis with PCA of GC/MS chromatograms and 1H-NMR spectra of urine from 3 studies conducted within the InnoMed PredTox project showing bile duct necrosis revealed alterations in urinary profiles with the onset of changes in clinical chemistry and histopathology. Alterations were mainly decreased Krebs cycle intermediates and changes in the aromatic gut flora metabolites, an effect that may result as a secondary effect from altered bile flow. In conclusion, metabonomics techniques are able to detect toxic lesions at the same time as histopathology and clinical chemistry. The metabolites found to be altered are common to most toxicities and are not organ-specific. A mechanistic link to the observed toxicity has to be established in order to avoid confounders such as body weight loss, pharmacological effects etc. For pattern recognition purposes, large databases are necessary. / Zur Bewertung von Metabonomics-Techniken zur frühen, nicht-invasiven Erkennung von Toxizität wurde Rattenurin nach wiederholter Gabe von Nephrotoxinen mit 1H-NMR und GC/MS analysiert. Untersucht wurden Gentamicin (s.c.-Gabe von 0, 60 und 120 mg/kg Körpergewicht (KG) 2x tägl. über 8 Tage), Ochratoxin A (p.o.-Gabe von 0, 21, 70 und 210 µg/kg KG 5xl wöchentlich für 90 Tage) und Aristolochiasäure (p.o.-Gabe von 0, 0.1, 1.0 und 10 mg/kg KG über 12 Tage). Proben von 16 Studien des InnoMed PredTox Projekts wurden mit 1H-NMR auf den histopathologischen Endpunkt Gallengangnekrose (BDN) untersucht. Folgende Parameter wurden zur 1H-NMR-Analyse mit Wasserunterdrückung verwendet: 1 M Phosphatpuffer, shift lock Reagenz D2O und Referenzierung der chemischen Verschiebung auf D4-Trimethylsilyl­propionsäure, noesygppr1d-Pulssequenz (Bruker). Zur multivariaten Datenanalyse wurden die Spektren in 0.04 ppm große „bins“ unterteilt. Zur GC/MS-Analyse wurden nach Proteinfällung mit Methanol die Urinproben getrocknet und mit Methoxyaminhydrochlorid in Pyridin und Methyl(trimethylsilyl)trifluoracetamid derivatisiert und auf einer DB5-MS -Säule getrennt. Die GC/MS-Chromatogramme wurden mit dem R-Programm-basierten XCMS-Softwarepaket Version 2.4.0 zur multivariaten Datenanalyse vorbereitet. Hauptkomponentenanalyse (PCA) zur Visualisierung von zeit- und dosisabhängigen Unterschieden zwischen Kontrollen und behandelten Tieren und „orthogonal projection to latent structures“-Diskriminantenanalyse (OPLS-DA) zur Identifizierung von Toxizitätsmarkern erfolgte mit SIMCA P+11.5 Die Chenomx-NMR-Suite wurde zur Identifizierung und Quantifizierung von 1H NMR-basierten Markern verwendet; GC/MS-basierte Marker wurden mit der „NIST Mass Spectral Database“ und durch Koelution mit Referenzstandards identifiziert. PCA unterschied Kontroll- von behandelten Tieren zum gleichen Zeitpunkt wie Histopathologie. Gegenüber klinisch-chemischen Parametern war Metabonomics in einigen Fällen empfindlicher. Gentamicin induzierte nach Tag 1 erniedrigte Ausscheidung von Citrat, 2-Oxoglutarat, Hippurat, Trigonellin und 3-Indoxylsulfat Urin, sowie erhöhte Ausscheidung von Lactat, Alanin, 5-Oxoprolin und Glucose, begleitet von geringfügigen Änderungen in klinisch-chemischen Parametern. Ochratoxin A verursachte nach zwei Wochen in einzelnen Tieren eine erniedrigte Ausscheidung von Citrat, 2-Oxoglutarat und Hippurat sowie eine erhöhte Ausscheidung von Glucose, myo-Inositol, N,N-Dimethylglycin, 5-Oxoprolin, Glycin, Alanin und Lactat, korrelierend mit Veränderungen in klinisch-chemischen Parametern und in der Histopathologie. Verwendung von Histopathologiedaten in multivariaten Modellen zur Markeridentifizierung erhöhte die Konfidenz der Marker. Aristolochiasäure induzierte eine erniedrigte Ausscheidung von Citrat, 2-Oxoglutarat, Hippurat und Creatinin und eine erhöhte Ausscheidung von 5-Oxoprolin, N,N-Dimethylglycin und Pseudouridin, ohne Veränderung der klinisch-chemischen Parameter oder der Histopathologie. Erniedrigte Ausscheidung von Hippurat weist auf eine veränderte Darmmikroflora hin; für das Aminoglykosid-Antibiotikum Gentamicin ist dies ein pharmakologischer Effekt, der für die perorale Gabe von Xenobiotica zu erwarten ist. Erniedrigte Ausscheidung von Citrat und 2-Oxoglutarat und erhöhte Ausscheidung von Lactat zeigt einen veränderten Energiestoffwechsel. Erhöhte Ausscheidung von Pseudouridin ist mit Zell­proliferation assoziiert und wurde nach Gabe der Kanzerogene Ochratoxin A und Aristolochiasäure beobachtet, bei denen proliferative Prozesse in der Histopathologie gefunden wurden. 5-Oxoprolin und N,N-Dimethyl­glycin deuten auf erhöhten oxidativen Stress hin. Erhöhte Glucose im Urin, ein Parameter zur Diagnose von Nierenschäden in der klinischen Chemie, wurde in allen drei Studien mit Nephrotoxinen beobachtet. GC/MS- und 1H-NMR-Daten von InnoMed-Studien mit Gallengang­nekrosen als histopathologischen Endpunkt zeigten Veränderung im Urin zeitgleich mit klinisch-chemischen Parametern und Histopathologie; hauptsächlich erniedrigte Ausscheidung von Citratzyklusintermediaten und Veränderungen bei Darmflora-assoziierten Metaboliten, – ein Effekt, der wahrscheinlich veränderten Gallenfluss zurückzuführen ist. Metabonomics ist prinzipiell zum gleichen Zeitpunkt wie klinisch-chemische Parameter und Histopathologie zur Erkennung von toxischen Veränderungen geeignet. Die veränderten Metaboliten sind jedoch zumeist nicht organspezifisch und können mit allgemeinen Toxizitätsmechanismen, wie oxidativem Stress oder Zellproliferation, in Verbindung gebracht werden. Für die Bewertung der Ergebnisse von Metabonomics-Studien ist ein mechanistisches Verständnis der Veränderungen im Urinprofil notwendig, um eine Trennung von toxischen Effekten und solchen, die auf pharmakologische Wirkung, Körpergewichtsverlust etc. zurückzuführen sind, zu erreichen. Für eine Vorhersage von toxischen Mechanismen aufgrund der Urinprofile ist eine größere Datengrundlage notwendig.
239

Biodegradação dos pesticidas clorpirifós, metil paration e profenofós por fungos de origem marinha / Biodegradation of pesticides chlorpyrifos, methyl parathion and profenofos by marine fungi

Silva, Natália Alvarenga da 26 April 2013 (has links)
Neste trabalho, foi realizada uma triagem com os fungos marinhos Aspergillus sydowii CBMAI 934, Aspergillus sydowii CBMAI 935, Aspergillus sydowii 1241, Penicillium decaturense CBMAI 1234, Penicillium raistrickii CBMAI 931, Penicillium raistrickii CBMAI 1235 e Trichoderma sp. CBMAI 932 com o objetivo de avaliar o potencial enzimático destes micro-organismos frente à biodegradação dos pesticidas organofosforados clorpirifós, metil paration e profenofós. Os fungos selecionados para as reações em meio líquido de malte 2%, que melhor adaptaram-se na presença do pesticida clorpirifós, foram as cepas de A. sydowii CBMAI 935 e Trichoderma sp. CBMAI 932, na presença de metil paration foram A. sydowii CBMAI 935 e P. decaturense CBMAI 1234 e na presença de profenofós foram os fungos A. sydowii CBMAI 935 e P. raistrickii CBMAI 931. Foram realizadas curvas analíticas com o objetivo de estimar a extensão da biodegradação dos pesticidas clorpirifós, metil paration, profenofós, e seus respectivos produtos de hidrólise, os derivados fenólicos 3,5,6-tricloro-2-piridinol, 4-nitrofenol e 4-bromo-2-clorofenol, respectivamente. As reações de biodegradação em meio líquido de malte 2% foram avaliadas com 10, 20 e 30 dias de reação com concentração inicial dos pesticidas organofosforados de 50 ppm. O pesticida, profenofós, apresentou uma biodegradação completa com o fungo P.raistrickii CBMAI 931 com 30 dias de reação, e 70% com o fungo A. sydowii CBMAI 935, para o mesmo período. Os fungos também apresentaram potencial para a degradação (ou conjugação) do metabólito, 4-bromo-2-clorofenol. Na presença dos fungos A. sydowii CBMAI 935 e Trichoderma sp. CBMAI 932, clorpirifós apresentou a menor degradação entre os pesticidas avaliados, com uma taxa de degradação de 63 e 72%, respectivamente, em 30 dias de reação. Os fungos selecionados não foram capazes de promover uma degradação apreciável do 3,5,6-tricloro-2-piridinol. Na presença dos fungos A. sydowii CBMAI 935 e P. decaturense CBMAI 1234, o metil paration apresentou uma degradação de 100% em 20 dias de reação. O 4-nitrofenol apresentou degradação (ou conjugação) de aproximadamente 50 e 40% na presença dos fungos A. sydowii CBMAI 935 e P. decaturense CBMAI 1234, respectivamente. Finalmente, os estudos apresentados comprovam a eficiência dos fungos de ambiente marinhos na biodegradação de pesticidas organofosforados. / In this work was performed a screening with the marine fungi Aspergillus sydowii CBMAI 934, Aspergillus sydowii CBMAI 935, Aspergillus sydowii 1241, Penicillium decaturense CBMAI 1234, Penicillium raistrickii CBMAI 931, Penicillium raistrickii CBMAI 1235 e Trichoderma sp. CBMAI 932 to evaluate the enzymatic potential of these microorganisms in the presence of organophosphate pesticides chlorpyrifos, methyl parathion and profenofos. The selected fungi for the reactions in liquid medium of malt 2%, which demonstrated better adaptation in presence of the pesticide chlorpyrifos, were the strains of A.sydowii CBMAI 935 and Trichoderma sp. CBMAI 932, in the presence of methyl parathion were A.sydowii CBMAI 935 and P. decaturense CBMAI 1234 and, in presence of profenofos were the fungi A. sydowii CBMAI 935 and P. raistrickii CBMAI 931. Analytical curves were performed in order to estimate the extent of biodegradation of the pesticide chlorpyrifos, methyl parathion, profenofos, and their hydrolysis products, 3,5,6-trichloro-2-pyridinol, 4-nitrophenol, 4-bromo 2-chlorophenol, respectively. Biodegradation reactions in liquid medium of malt 2% were evaluated with 10, 20 and 30 days with an initial concentration of 50 ppm of organophosphate pesticides. Profenofos, presented a complete biodegradation (100%) with the fungus P.raistrickii CBMAI 931, in 30 days of reaction, and 70% of biodegradation in the presence of the fungus A. sydowii CBMAI 935, at the same period. The fungi also showed a potential for degradation (or conjugation) of 4-bromo-2-chlorophenol. In the presence of the fungus A. sydowii CBMAI 935 and Trichoderma sp. CBMAI 932, chlorpyrifos exhibited the lowest degradation among the evaluated pesticides, presenting a degradation rate of 63 and 72%, respectively, at 30 days of reaction. The selected fungi were not capable of promoting an appreciable degradation of 3,5,6-trichloro-2-pyridinol. In the presence of A. sydowii CBMAI 935 and P. decaturense CBMAI 1234, methyl parathion showed a degradation of 100%, at 20 days of reaction. The 4-nitrophenol showed a degradation (or conjugation) of approximately 50 and 40% in the presence of the fungus A. sydowii CBMAI 935 and P. decaturense CBMAI 1234, respectively. Finally, the presented studies demonstrated the efficiency of the marine fungi in biodegradation of organophosphate pesticides.
240

Desenvolvimento e validação de método para análise de nicotina e cotinina em amostras de mecônio utilizando a cromatografia em fase gasosa acoplada à espectrometria de massas / Development and validation of a methodology for analysis of nicotine and cotinine in meconium samples using gas chromatography-mass spectrometry.

Barros, Luiza Saldanha Ribeiro 18 April 2011 (has links)
O mecônio é uma matéria fecal que começa a acumular no intestino do feto por volta do terceiro mês de gestação e normalmente é eliminado nos primeiros dias de vida do recém nascido. No mecônio ocorre o acúmulo de substâncias com as quais a mãe entrou em contato durante o período de gestação e, portanto, sendo possível avaliar a exposição fetal. Nos casos de mães fumantes, compostos presentes no tabaco tais como nicotina e substâncias que são formadas após a metabolização da nicotina como por exemplo a cotinina, podem ser também detectadas nas amostras de mecônio, já que ocorre o acúmulo de nicotina e seus metabólitos no mesmo. O uso do cigarro durante o período gestacional acarreta em uma série de problemas ao feto como baixo peso ao nascer, parto pré-maturo, doenças no trato respiratório, dentre outros. Nos dias atuais é possível fazer a pesquisa de drogas lícitas e ilícitas em várias amostras biológicas tais como, sangue, urina, cabelo, fluido oral, mecônio, entre outras. O mecônio é uma boa opção, por vários motivos: amostragem fácil e não invasiva (a coleta pode ser feita na fralda), indica o histórico do uso de substâncias pela mãe durante a gestação por ser cumulativo, etc. O objetivo foi desenvolver e validar um método analítico empregando cromatografia em fase gasosa acoplada a espectrometria de massas para a determinação de nicotina e, seu metabólito, cotinina em amostras de mecônio coletadas de recém nascidos. Para o desenvolvimento do método foi utilizado 0,5g de mecônio e os analitos foram extraídos com metanol e em seguida a amostra foi submetida a purificação através da extração em fase sólida utilizando cartuchos Bond Elut Certify I. O método foi validado de acordo com os parâmetros estabelecidos pela ANVISA e demonstrou linearidade de 160 1600 ng/g para nicotina e de 160 1000 ng/g para cotinina. Os limites de detecção estabelecidos foram de 10 ng/g para nicotina e 60 ng/g para cotinina, enquanto os limites de quantificação foram de 60 ng/g para nicotina e 100 ng/g para cotinina. A exatidão apresentou valores de 91,73% a 103,73%, a precisão intra-ensaio variou entre 3,21% a 10,86%, e a precisão inter-ensaio obteve valores entre 4,91% a 9,88%. O método validado foi aplicado em amostras de mecônio coletadas no Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto (HCFMRP-USP). / Meconium is a fecal matter passed by the newborn after birth. It begins to form around the 3th month of gestation and accumulates in the fetus until birth. Substances which the mothers had contact during the gestation period may accumulate in meconium and, therefore, its possible to assess fetal exposure. Substances from the tobacco smoke, like nicotine and its metabolite cotinine, also accumulates in the meconium and can be detected .Maternal smoking during pregnancy is hazardous to the fetus and it is associated with low birth weight, prematurity, respiratory tract infections and others. Nowadays it is possible to assess licit and illicit drugs in several biological samples like blood, urine, hair, oral fluid, meconium and others. Meconium is the best choice because its easy to collect and its noninvasive, indicates a history of substances use by the mother in the latter half of pregnancy, etc. The purpose of this study was to develop and validate a methodology using gas chromatography-mass spectrometry to assess nicotine and cotinine in meconium samples collected from newborns. To the development of the methodology 0,5g of meconium was used per assay and the analytes were extracted from the matrix using methanol. Then, a solid phase extraction was applied using Bond Elut Certify I cartridges. The methodology was validated in the range of 160 1600 ng/g for nicotine and 160 - 1000 ng/g for cotinine. The limit of detection established was 10 ng/g for nicotine and 60 ng/g for cotinine, while the limit of quantification was 60 ng/g for nicotine and 100 ng/g for cotinine. The accuracy showed values between 91,73% and 103,73%, the intra-assay precision between 3,21% and 10,86% and the inter-assay precision between 4,91% and 9,88%. The validated methodology was applied to analysis of meconium samples collected from newborns in the Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto (HCFMRP-USP).

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