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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.
41

Residuos de antimicrobianos em peixe : depleção residual e desenvolvimento de metodos analiticos / Antimicrobials residues in fish : residual depletion and development of analytical methods

Paschoal, Jonas Augusto Rizzato 21 December 2007 (has links)
Orientador: Susanne Rath / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-10T13:13:12Z (GMT). No. of bitstreams: 1 Paschoal_JonasAugustoRizzato_D.pdf: 2545620 bytes, checksum: 047e1d72fd2de11da7411d954b23d23f (MD5) Previous issue date: 2007 / Resumo: Os antimicrobianos são largamente empregados na medicina veterinária, e resíduos destes podem permanecer nos alimentos de origem animal, acima de valores considerados seguros, quando não são respeitadas as boas práticas veterinárias. Este trabalho teve por objetivos: (i) desenvolver e validar métodos analíticos para a determinação de multi-resíduos de quinolonas (enrofloxacina, ciprofloxacina, danofloxacina, sarafloxacina, ácido oxolínico e flumequina) em carne de peixe, usando a cromatografia líquida de alta eficiência associada a detecção por fluorescência (HPLC-FL) e cromatografia líquida associada a espectrometria de massas em tandem por interface de ionização por electrospray e (LC-ESI-MS/MS Q-ToF); (ii) desenvolver e validar métodos analíticos para a determinação de oxitetraciclina (OTC) em ração e carne de tilápias por HPLC-DAD e HPLC-FL, respectivamente e (iii) realizar um ensaio com tilápias (Oreochromis niloticus) para avaliar a depleção da OTC na carne desses peixes. De modo geral, a extração das quinolonas e da OTC da carne de peixes foi conduzida por extração sólido líquido seguida da limpeza do extrato em cartuchos de extração em fase sólida. A separação cromatográfica dos antimicrobianos foi realizada em coluna de fase reversa octadecil híbrida. Os métodos foram validados mediante avaliação dos seguintes parâmetros: faixa linear, linearidade, sensibilidade, seletividade, limites de detecção e quantificação, precisão intra e inter-ensaios e exatidão. Para o método LC-MS/MS foi também avaliado o efeito matriz. Todos os métodos foram considerados adequados aos objetivos propostos neste trabalho. Para avaliar a depleção de OTC na carne de tilápias, os peixes (peso médio de 93 a 115 g) receberam o fármaco via ração na dose de 80 mg OTC/kg peso vivo/dia, por cinco dias consecutivos. A temperatura da água durante o ensaio variou de 16,5 a 24,5 °C. A curva de depleção se ajustou a um modelo exponencial de primeira ordem. O tempo de meia vida de eliminação foi de 2,5 dias e o período de carência estimado foi de 5 dias / Abstract: Antimicrobials are widely employed in veterinary medicine, and their residues could remain in food of animal origin above values considered safe if good veterinary practices are not followed. The aim of this work is to address (i) the development and validation of analytical methods using high performance liquid chromatography with fluorescence detection (HPLC-FL) and liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS Q-Tof) for the determination of multi residues of quinolones (enrofloxacin, ciprofloxacin, danofloxacin, sarafloxacin, oxolinic acid and flumequine) in fish; (ii) the development and validation of analytical methods for the determination of oxytetracycline (OTC) in fish feed and tilapia fish fillets using HPLC-DAD and HPLC-FL, respectively, and (iii) the study of tilapias (Oreochromis niloticus) in order to evaluate the depletion of OTC from the fish fillet. In general, the extraction of the quinolones and OTC from the fish matrix was conducted by solid-liquid extraction followed by clean-up on solid phase extraction cartridges. The antimicrobials chromatographic separation was performed on a reverse phase octadecyl hybrid column. The methods were validated through the following parameters: linear range, linearity, sensitivity, selectivity, detection limit, quantitation limit, intra- and inter-assay precision and accuracy. For the LC-MS/MS method, the matrix effect was also evaluated. All methods were adequate to the proposed objectives. In order to evaluate the depletion of OTC in the tilapia fillets, the fish (weight range 93 ¿ 115 g) were given medicated feed in a concentration of 80 mg OTC/kg body weight/day for five consecutive days. The water temperature was between 16.5 to 24.5 °C during the treatment. The depletion curve was fitted to an exponential first order model. The elimination half-life was 2.5 days and the withdrawal period was estimated as five days / Doutorado / Quimica Analitica / Doutor em Ciências
42

Molecular breeding of functional spinaches rich in folate and betacyanin based on metabolome analysis / メタボローム解析に基づく葉酸及びベタシアニン富化機能性ホウレンソウの育種

Ohtani, Yuta 23 March 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第22487号 / 農博第2391号 / 新制||農||1076(附属図書館) / 学位論文||R2||N5267(農学部図書室) / 京都大学大学院農学研究科応用生命科学専攻 / (主査)教授 植田 充美, 教授 梅澤 俊明, 教授 栗原 達夫 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
43

Quantitative Determination of Total Methamphetamine and Active Metabolites in Rat Tissue by Liquid Chromatography With Tandem Mass Spectrometric Detection

Hendrickson, Howard, Laurenzana, Elizabeth, Owens, S. Michael 22 November 2006 (has links)
High-throughput liquid chromatography with tandem mass spectrometric detection (LC-MS/MS) methodology for the determination of methamphetamine (METH), amphetamine (AMP), 4-hydroxymethamphetamine (4-OH-METH), and 4-hydroxyamphetamine (4-OH-AMP) was developed and validated using simple trichloroacetic acid sample treatment. The method was validated in rat serum, brain, and testis. Lower limits-of-quantitation (LOQ) for METH and AMP were 1 ng·mL-1 using positive ion electrospray tandem mass spectrometry (MS/MS). The accuracy of the method was within 25% of the actual values over a wide range of analyte concentrations. The within-assay precision was better than 12% (coefficient of variation). The method was linear over a wide dynamic range (0.3-1000 ng·mL-1). Quantitation was possible in all 3 matrices using only serum standards because of minimal matrix-associated ion effects or the use of an internal standard. Finally, the LC-MS/MS method was used to determine serum, brain, and testis METH and AMP concentrations during a subcutaneous infusion (5.6 mg kg-1 day-1) of METH in rats. Concentrations of 4-OH-AMP and 4-OH-METH were below the LOQ in experimental samples. The bias introduced by using serum calibrators for the determination of METH and AMP concentrations in testis and brain was less than 8% and insignificant relative to the interanimal variability.
44

Analysis of ketamine and xylazine in fur and bones using multidimensional liquid chromatography tandem mass spectrometry

Karanth, Neesha Claire 21 February 2019 (has links)
While ketamine is traditionally administered for anesthesia or pain management, illicit usage is often seen in forensic cases either as a recreational drug or as a tool in drug-facilitated sexual assault. Xylazine is an anesthetic agent used in veterinary medicine and does not have FDA approval for use in humans. However, it has recently been observed as a cutting agent in heroin. Post-mortem specimens present many challenges when it comes to toxicological analysis. Due to compound degradation and decomposition factors, analytes present at trace levels may be missed in blood and urine. Hair, bone, and insects have recently been investigated as alternative matrices for postmortem analysis due to their increased durability compared to more traditional matrices. However, this durability increases the difficulties in extracting and isolating compounds of interest from these matrices via traditional extraction and chromatography methods. These methods require lengthy extraction times and extensive cleanup steps in order to obtain samples suitable for analysis. Utilizing multiple instrumentation combinations, analysts are able to detect compounds at trace levels. Through the use of multidimensional chromatography, several time-consuming extraction steps can be eliminated while still retaining the ability of trace level detection and quantitation. Using Waters Oasis® HLB PRiME solid phase extraction cartridges using a methanol pH10 loading and an acetonitrile pH3 elution, a solvent extraction yielded linear dynamic ranges of 2pg/mL-1ng/mL and 5pg/mL-1ng/mL for xylazine and ketamine respectively. Rat specimens utilized in this project were treated as per an Institutional Animal Care and Use Committee (IACUC) protocol. The test rodents received an acute dosage of 2mg/mL of xylazine and 24mg/mL of ketamine approximately half an hour prior to death. The 14 test samples were placed outside directly on the ground at the Boston University Forensic Anthropology Outdoor Research Facility (Holliston, MA, U.S.A.) for a period of 6 months. A 15th rat was kept in -20°C until analysis to serve as a Time=0 sample. The outdoor samples were recovered and de-fleshed along with the Time=0 sample manually. Drug-free hair samples were donated anonymously as per Internal Review Board (IRB) protocols.
45

γ線照射によって生じるクリスタリン中の酸化、脱アミド化部位の迅速分析

金, 仁求 23 March 2016 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第19517号 / 理博第4177号 / 新制||理||1600(附属図書館) / 32553 / 京都大学大学院理学研究科化学専攻 / (主査)教授 藤井 紀子, 教授 三木 邦夫, 教授 杉山 弘 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM
46

A method for chemical proteomics based on the selective localization of labeling molecules in living systems / 生体における小分子局在に基づいたケミカルプロテオミクス手法

Yasueda, Yuuki 23 March 2016 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19752号 / 工博第4207号 / 新制||工||1649(附属図書館) / 32788 / 京都大学大学院工学研究科合成・生物化学専攻 / (主査)教授 濵地 格, 教授 梅田 眞郷, 教授 跡見 晴幸 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM
47

THRAP3 interacts with and inhibits the transcriptional activity of SOX9 during chondrogenesis / THRAP3は軟骨発生の際にSOX9と結合し、その転写活性を抑制する

Sono, Takashi 23 January 2018 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20793号 / 医博第4293号 / 新制||医||1025(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 妻木 範行, 教授 鈴木 茂彦, 教授 瀬原 淳子 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
48

Investigation of Ribonucleic Acid Post-transcriptional Modifications by Optimized LC-MS/MS Methods

Zhao, Ruoxia 05 October 2021 (has links)
No description available.
49

Structure and biological activities of hydrophobic short chain pyroglutamyl peptides in fermented foods and food protein hydrolysates / 発酵食品及び食品タンパク質加水分解物中に存在する疎水性短鎖ピログルタミルペプチドの構造とその生理機能

Shirako, Saki 23 March 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第22499号 / 農博第2403号 / 新制||農||1077(附属図書館) / 学位論文||R2||N5279(農学部図書室) / 京都大学大学院農学研究科応用生物科学専攻 / (主査)教授 佐藤 健司, 教授 菅原 達也, 准教授 豊原 治彦 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
50

Séquençage des peptides par spectrométrie de masse en tandem à ionisation par électronébulisation

Bergeron, Annik January 2001 (has links)
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

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