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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.
51

Perfil hematológico, bioquímico, histopatológico e toxicológico de gatos induzidos experimentalmente com monofluoroacetato de sódio /

Zuanaze, Rita de Cássia Collicchio. January 2006 (has links)
Orientador: Michiko Sakate / Banca: Noeme Sousa Rocha / Banca: Manoel Lima de Menezes / Banca: Mara Regina Stipp Balarin / Banca: Silvana Lima Gorniak / Resumo: O monofluoroacetato de sodio (MFAS) ou composto 1080 e um rodenticida que foi amplamente utilizado para o controle de roedores e predadores domesticos, apos sua descoberta em 1945. Este potente rodenticida age bloqueando o ciclo de Krebs por acao do seu metabolito toxico, o fluorocitrato, e como consequencia, inibe a resposta celular e a producao de ATP. O MFAS foi proibido por lei no Brasil e em diversos paises, mas seu uso indiscriminado continua causando diversos casos de intoxicacoes potencialmente fatais no homem e animais domesticos, principalmente em caes e gatos, representadas por alteracoes neurologicas e cardiacas. Pretendeu-se com este estudo caracterizar o perfil hematologico e bioquimico, as alteracoes histopatologicas e toxicologicas de gatos intoxicados experimentalmente com MFAS, com o objetivo de determinar metodos diagnosticos eficazes. Para tanto, foram utilizadas amostras de sangue de 16 gatos intoxicados experimentalmente com 0,45mg/kg de MFAS, por via oral. Estas amostras foram colhidas por puncao jugular e analisadas quanto ao perfil hematologico, bioquimica serica e analises toxicologicas em cromatografia liquida de alta eficiencia (CLAE), para deteccao e quantificacao do MFAS no soro dos animais. Avaliaram-se tambem as lesoes macro e microscopicas dos animais intoxicados que vieram a obito. Observaram-se leucopenia e trombocitopenia transitorias; hiperglicemia, aumento das enzimas musculares creatinoquinase (CK) e creatinoquinase fracao cardiaca (CK-MB); observaram-se tambem hipocalemia, hipofosfatemia e hipomagnesemia. Os achados macroscopicos e histopatologicos demonstraram lesoes caracteristicas de processos isquemicos e as analises toxicologicas demonstraram um metodo diagnostico simples e eficiente...(Resumo completo, clicar acesso eletrõnico abaixo) / Abstract: Sodium monofluoroacetate (SMFAC) or 1080 compound is a potent rodenticide, largely used since 1945 for rodent and domestic pest control. The toxic effects of SMFAC are caused by fluorocitrato, a toxic metabolite, which has a competitive action with aconitase enzyme, leading to citrate accumulation and interferes in energy production by Krebs cycle blockade. In Brazil, although prohibited by law, there is illegal use, keep causing intoxication in children and domestic animals, specially dogs and cats. The most common intoxication clinical signs are from the cardiac and neurological alterations. In the present study, 16 domestic cats were intoxicated with oral doses of monofluoroacetate (0.45mg/kg). The hematologic and biochemical profiles, and histophatological and blood serum toxicological analysis by high performance liquid chromatography (HPLC) were made to looking for a efficient diagnosis methods. The hematologic profile showed transitory leucopenia and trombocitopenia; the biochemical profile presented hiperglycemia, increase of creatinoquinase enzyme (CK) and creatinoquinase cardiac fraction (CK-MB), hypokalemia and hypophosfatemia were observed. The macrocospic and histopathological findings showed lesions characteristic of degenerative and ischemic processes. The toxicological analysis was shown to be a simple and efficient diagnostic method. SMFAC was detected in 75% of the serum samples analysed, and it was verified an average concentration of 0.32 ìg/mL in them; 4.81% of the serum samples did not show metabolized SMFAC six hours after the induced intoxication of the animals used in this study. / Doutor
52

Organic Fluorine in Crystal Engineering : Consequences on Molecular and Supramolecular Organization

Dikundwar, Amol G January 2013 (has links) (PDF)
The thesis entitled “Organic fluorine in crystal engineering: Consequences on molecular and supramolecular organization” consists of six chapters. The main theme of the thesis is to address the role of substituted fluorine atoms in altering the geometrical and electronic features in organic molecules and its subsequent consequences on crystal packing. The thesis is divided into three parts. Part I deals with compounds that are liquids under ambient conditions, crystal structures of which have been determined by the technique of in situ cryocrystallography. Part II demonstrates the utilization of in situ cryocrystallography to study kinetically trapped metastable crystalline phases that provide information about crystallization pathways. In part III, crystal structures of a series of conformationally flexible molecules are studied to evaluate the consequences of fluorine substitution on the overall molecular conformation. The genesis and stabilization of a particular molecular conformation has been rationalized in terms of variability in intermolecular interactions in the crystalline state. Part I. In situ cryocrystallography: Probing the solid state structures of ambient condition liquids. Chapter 1 discusses the crystal structures of benzoyl chloride and its fluorinated analogs. These compounds have been analysed for the propensity of adoption of Cl···O halogen bonded dimers and catemers. The influence of conformational and electronic effects of sequential fluorination on the periphery of the phenyl ring has been quantified in terms of the most positive electrostatic potential, VS,max (corresponding to σ-hole) on the Cl-atom. It is shown that fluorine also exhibits “amphoteric” nature like other heavier halogens, particularly in presence of electron withdrawing groups. Although almost all the derivatives pack through C–H···O, C–H···F, C–H···Cl, Cl···F, C–H···π and π···π interactions, the compound 2,3,5,6-tetrafluorobenzoyl chloride exhibited a not so commonly observed Cl···O halogen bonded catemer. On the other hand, the proposed Cl···O mediated dimer is not observed in any of the structures due to geometrical constraints in the crystal lattice. Chapter 2 presents the preferences of fluorine to form hydrogen bond (C–H···F) and halogen bonds (X···F; X= Cl, Br, I). Crystal structures of all three isomers of chloro-, bromo-and iodo-fluorobenzene have been probed in order to gain insights into packing interactions preferred by fluorine and other heavier halogens. It has been observed that homo halogen…halogen (Cl···Cl, Br···Br and I···I) contacts prevail in most of the structures with fluorine being associated with the hydrogen atom forming C–H···F hydrogen bond. The competition between homo and hetero halogen bonds (I···I vs I···F) is evident from the packing polymorphism exhibited by 4-iodo fluorobenzene observed under different cooling protocols. The crystal structures of pentafluoro halo (Cl, Br, I) benzenes were also determined in order to explore the propensity of formation of homo halogen bonds over hetero halogen bonds. Different dimeric and catemeric motifs based on X···F and F···F interactions were observed in these structures. Chapter 3 focuses on the effect of different cooling protocols in generating newer polymorphs of a given liquid. The third polymorph (C2/c, Z'=6) of phenylacetylene was obtained by sudden quenching of the liquid filled in capillary from a hot water bath (363 K) to the nitrogen bath (< 77 K). Also, different polymorphs were obtained for both 2¬fluoro phenylacetylene (Pna21, Z'=1) and 3-fluoro phenylacetylene (P21/c, Z'=3) when crystallized by sudden quenching in contrast to the generally followed method of slow cooling which results in isostructural forms (P21, Z'=1). The rationale for these kinetically stable “arrested” crystalline configurations is provided in part II of the thesis. Part II. Tracing crystallization pathways via kinetically captured metastable forms. Chapter 4 explains the utilization of the new approach of sudden quenching of liquids (detailed in chapter 3) to obtain kinetically stable (metastable) crystalline phases that appear to be closer to the unstructured liquids. Six different examples namely, phenylacetylene, 2-fluorophenylacetylene, 3-fluorophenylacetylene, 4-fluorobenzoyl chloride, 3-chloro fluorobenzene and ethyl chloroformate are discussed in this context. In each case, different polymorphs were obtained when the liquid was cooled slowly (100 K/h) and when quenched sharply in liquid nitrogen. The relationship between these metastable forms and the stable forms (obtained by slow cooling) combined with the mechanistic details of growth of stable forms from metastable forms provides clues about the crystallization pathways. Part III. Conformational analysis in the solid state: Counterbalance of intermolecular interactions with molecular and crystallographic symmetries. Chapter 5 describes the crystal structures of a series of conformationally flexible molecules namely, acetylene and diacetylene spaced aryl biscarbonates and biscarbamates. While most of the molecules adopt commonly anticipated anti (transoid) conformation, some adopt unusual cisoid and gauche conformations. It is shown that the unusually twisted conformation of one of the compounds [but-2-yne-bis(2,3,4,5,6¬pentafluorocarbonate)] is stabilized mainly by the extraordinarily short C–H···F intermolecular hydrogen bond. The strength of this rather short C–H···F hydrogen bond has been authenticated by combined single crystal neutron diffraction and X-ray charge density analysis. It has also been shown that the equi-volume relationship of H-and F-atoms (H/F isosterism) can be explored to access various possible conformers of a diacetylene spaced aryl biscarbonate. While biscarbonates show variety of molecular conformations due to absence of robust intermolecular interactions, all the biscarbamates adopt anti conformation where the molecules are linked with antiparallel chains formed with N–H···O=C hydrogen bonds. Chapter 6 presents a unique example where the commonly encountered crystallographic terms namely, high Z' structure, polymorphism, phase transformation, disorder, isosterism and isostructuralism are witnessed in a single molecular species (parent compound benzoylcarvacryl thiourea and its fluorine substituted analogs). The origin of all these phenomenon has been attributed to the propensity of formation of a planar molecular dimeric chain mediated via N–H···O [R2 (12)] and N–H···S [R2 (8)] dimers.
53

A Comparative Analysis of Per- andPolyfluoroalkyl Substances (PFAS) and ExtractableOrganofluorine (EOF) Using Solid PhaseExtraction-Weak Anion Exchange and Ion PairExtraction in SerumMarichal SalamehSpring 2021Independent project

Salameh, Marichal January 2021 (has links)
Per- and polyfluorinated substances (PFAS) are compounds that consist of a carbon chainbackbone that is partially or entirely fluorinated, with an addition of a functional group. SomePFAS are known as persistent organic pollutants (POPs) and have therefore been drawing a lot ofattention as well as increased concerns. PFAS have been detected in humans, wildlife and theenvironment and some have exhibited toxic effects such as hepatotoxicity, immunotoxicity,reproductive toxicity and endocrine disruption as well as being persistent and bioaccumulative.Serum, plasma and whole blood have been used as biomonitoring matrices in many studies toevaluate human exposure to PFAS. Restrictions have been applied to some PFAS, but thesecompounds are still ubiquitous. This study will investigate the performance (recovery, matrixeffect (ME) in terms of intra-/inter-day repeatability) of ion-pair extraction (IPE) and solid phaseextraction with weak anion exchange (SPE-WAX). The extraction methods were adapted fromliterature and 13 PFAS were selected for this work based on prior biomonitoring studies. Thetarget PFAS content was analyzed with liquid chromatography coupled with tandem massspectrometry (LC-MS/MS). The extraction methods were also compared for extractableorganofluorine (EOF) extraction in terms of blank levels as well as the amount extracted withdifferent methods; the EOF content was measured with combustion ion chromatography (CIC).The EOF levels were used to estimate the amount of unidentified organofluorine (UOF), to avoidunderestimating potential health hazards. Samples extracted using IPE had an average ionizationenhancement of 9%, while SPE-WAX showed an average ionization suppression of -1%. SPEWAXshowed higher average recoveries for procedural blanks (78%), horse serum (96%) andhuman serum (95%) in comparison to IPE (69%, 36%, 88%, respectively). The CIC analysis forEOF content was observed to be below MDL (&lt;50 ng/mL F) with some contaminations observedin the procedural blanks.

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