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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.
11

Nh-pirazóis e isoxazóis: síntese mecanicamente ativada por grinding / Nh-pyrazoles and isoxazoles: synthesis mechanically activated by grinding

Longhi, Kelvis 30 July 2010 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / The synthesis of twelve NH-pyrazoles from the cyclocondensation reaction of β-dimethylaminovinylketones ([R1C(O)C(R2)=CHN(Me)2], where R1 = Me, C6H5, 3- MeO-C6H4, 4-Me-C6H4, 4-MeO-C6H4, 4-F-C6H4, 4-Cl-C6H4, 4-Br-C6H4, 4-O2N-C6H4, fur-2-il, tien-2-il; R2 = H, 2-MeO-C6H4 and R1, R2 = -(CH2)3C(O)- with hydrazine sulfate is reported. In this work, it was also demonstrated the synthesis of twelve isoxazoles from the cyclocondensation reaction of β-dimethylaminovinylketones where R1 = Me, C6H5, 3-MeO-C6H4, 4-Me-C6H4, 4-MeO-C6H4, 4-F-C6H4, 4-Cl-C6H4, 4-Br-C6H4, 4-biphenyl, naphthalen-2-yl, 4-O2N-C6H4, thien-2-yl and R2 = H, 2-MeOC6H4 with hydroxylamine hydrochloride. The reactions were performed in the presence of p-toluene sulfonic acid as the catalyst through two methodologies: (i) by the solvent-free grinding method, and (ii) using the conventional method, ethanol reflux. In addition, the Grindstone Chemistry methodology demonstrated that largescale synthesis is also possible. Making a comparison with the classical reaction conditions, which employ molecular solvent (ethanol), the grinding method has as main advantages of shorter reaction time (5-15 min), higher product yields (60-92%), mild reaction conditions as well as being environmentally friendly. / Neste trabalho é descrita a síntese de uma série de doze NH-pirazóis a partir da reação de ciclocondensação de β-dimetilaminovinilcetonas ([R1C(O)C(R2)=CHN(Me)2], onde R1 = Me, C6H5, 3-MeO-C6H4, 4-Me-C6H4, 4-MeOC6H4, 4-F-C6H4, 4-Cl-C6H4, 4-Br-C6H4, 4-O2N-C6H4, fur-2-il, tien-2-il; R2 = H, 2-MeOC6H4 e R1, R2 = -(CH2)3C(O)- com sulfato de hidrazina. Também foi realizada a síntese de uma série de doze isoxazóis a partir da reação de ciclocondensação de β-enamino cetonas, onde R1 = Me, C6H5, 3-MeO-C6H4, 4-Me-C6H4, 4-MeO-C6H4, 4- F-C6H4, 4-Cl-C6H4, 4-Br-C6H4, 4-bifenil, naft-2-il, 4-O2N-C6H4, tien-2-il e R2 = H, 2-MeO-C6H4 com cloridrato de hidroxilamina. As reações para obtenção dos compostos heterocíclicos foram realizadas na presença de ácido p-tolueno sulfônico (ác. p-TsOH) como catalisador através de duas metodologias: (i) utilizando o método grinding na ausência de solvente, e (ii) utilizando metodologia convencional, refluxo em etanol. O método Grindstone Chemistry foi testado e demonstrou que a síntese em grande escala também é possível. Os resultados obtidos mostraram que o grinding proporciona uma redução no tempo da reação (5-15 min), altos rendimentos (60-92%), condições de reação brandas, além de ser uma metodologia ambientalmente aceitável.
12

Cyclooxygenase-2 inhibitors and knee prosthesis surgery

Meunier, Andreas January 2008 (has links)
Adverse effects of cyclooxygenase (COX) inhibitors on bone healing have previously been demonstrated in diaphyseal fracture models in animals. In spite of that, they are widely used as postoperative analgesics in orthopaedic surgery. After joint replacement, a bone repair process starts at the interface between bone and cement. If this process is disturbed, the prosthesis may never become rigidly fixed to the bone, leading to migration and with time loosening. This thesis investigates the effects of a selective COX-2 inhibitor (parecoxib or celecoxib) on bone healing in metaphyseal bone in a rat model and on knee prosthesis migration after total knee replacement, as measured with radiostereometric analysis. Blood loss, postoperative recovery, and the 2-year subjective outcome, were also measured. In addition, a hemoglobin dilution method for blood loss estimation, used in this thesis, was evaluated. In the first study, pull-out force of a screw inserted in metaphyseal bone of the tibia in rats was only marginally decreased by parecoxib after 7 days but not after 14 days. In the second and third study, celecoxib treatment resulted in less pain postoperatively in conjunction with total knee replacement (TKR), but no effects were seen on blood loss, range of motion, subjective outcome, or prosthesis migration after 2 years. Comparing the true blood loss of blood donors with the blood loss estimated by the hemoglobin dilution method, this method was found to underestimate the true blood loss. It is therefore not suitable for calculation of the absolute blood loss volume, but may be used for a rough estimate. In summary, celecoxib and presumably other cyclooxygenase inhibitors seems not likely to increase the risk of prosthesis loosening.
13

Cyclooxygenase-2 inhibitors and knee prosthesis surgery /

Meunier, Andreas, January 2008 (has links) (PDF)
Diss. (sammanfattning) Linköping : Linköpings universitet, 2008. / Härtill 4 uppsatser.
14

Novos Espirocromenil-Trifluoretanonas a partir de Reações de Trifluoracetilação de Adutos de Kabbe e seus Espiro[diidrocromeno-cicloalcan]pirazóis e Isoxazóis Derivados / New Spirochromenyl-Trifluoroethanones from Trifluoroacetylation Reactions of Kabbe Adducts and their Spiro[dihydrochromeno-cycloalcan]pyrazoles and Isoxazoles Derivatives

Garcia, Fábio Dutra 03 December 2013 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work describes firstly an efficient and regioselective method for the synthesis of a new series of 2,2,2-trifluoro-1-[4-methoxy-spiro(2H-chromen-2,1 -cycloalkan)-3-yl]ethanones from the Kabbe adducts (spiro[chroman-2,1 -cycloalkan]-4-ones). Yields of 38 % to 61 % were obtained when trifluoroacetylation reactions of mixtures of enolethers and/or acetals derived from four spiro ketones (Kabbe adducts) were performed at a temperature of 45 oC and employing anhydrous chloroform as the solvent. Subsequently, when the respective trifluoroacetylated Kabbe adducts reacted with phenylhydrazine and methylhydrazine at a 1:1 molar ratio in refluxing ethanol for 24 hours, a new series of seven examples of a novel spiro-condensed heterocyclic system, namely 1(2)-methyl(phenyl)-3-(trifluoromethyl)-1,4(2,4)-dihydro-spiro(chromen[4,3-c]pyrazole-4,n -cycloalkanes) where cycloalkanes are cyclopentane, cyclohexane and cycloheptane (n = 1) and tetrahydro-2H-pyran (n = 2) were isolated at yields of between 35 % and 51 %. NMR and X-ray diffraction techniques demonstrated clearly that reactions from methylhydrazine and phenylhydrazine were regioselective and allowed to isolate separately the 1,3- and 2,3-trifluoromethylated isomers, respectively. Subsequently, two examples of new 3-hydroxy-3-(trifluoromethyl)-3,3a-dihydro-4H-spiro(chromen[4,3-c]isoxazole-4,1 -cycloalkanes), derivated from cyclopentanone and cyclopentanone, were obtained from the reaction of 2,2,2-trifluoro-1-[4-methoxy-spiro(2H-chromen-2,1 -cycloalkan)-3-yl]ethanones with hydroxylamine hydrochloride in yields of 42% and 58%, respectively. Finally, the structures of new spiro heterocycles were determined with the aid and simultaneous application of 1H-, 13C{1H}- and 19F-NMR, X-ray monocrystal diffraction, Mass Spectrometry and DFT calculation techniques and their purity were proved by elemental analysis or High Resolution Mass Spectrometry (HRMS). / O presente trabalho descreve inicialmente um método eficiente e regiosseletivo para a síntese de uma nova série de 2,2,2-triflúor-1-[4-metóxi-espiro(2H-cromen-2,1 -cicloalcan)-3-il]etanonas a partir de adutos de Kabbe (espiro[croman-2,1 -cicloalcan]-4-onas). Rendimentos de 38% a 61% foram obtidos quando reações de trifluoracetilação de misturas de enoléteres e/ou acetais derivados de quatro espiro cetonas (adutos de Kabbe) foram realizadas a 45 ºC usando clorofórmio anidro como solvente. Subsequentemente, quando os respectivos adutos de Kabbe trifluoracetilados foram reagidos com fenilhidrazina ou metilhidrazina, em relação molar de 1:1, sob refluxo de etanol por 24 horas, uma série de sete exemplares de um novo sistema heterocíclico espiro-condensado, denominado 1(2)-metil(fenil)-3-(trifluormetil)-1,4(2,4)-diidro-espiro(chromen[4,3-c]pirazol-4,n -cicloalcanos) onde os cicloalcanos são ciclopentano, ciclohexano e cicloheptano (n = 1) e tetraidro-2H-pirano (n = 2), foi isolada em rendimentos entre 35 % e 51 %. Técnicas de RMN e de difração de raios-X demonstraram claramente que as reações a partir da metilhidrazina e da fenilhidrazina foram regiosseletivas e permitiram isolar separadamente os isômeros trifluormetilados 1,3 e 2,3, respectivamente. Em sequência, dois exemplares de novas 3-hidróxi-3-(trifluormetil)-3,3a-diidro-4H-espiro(cromen[4,3-c]isoxazol-4,1 -cicloalcanos), derivados da ciclopentanona e ciclohexanona, foram obtidos a partir da reação de 2,2,2-triflúor-1-[4-metóxi-espiro(2H-cromen-2,1 -cicloalcan)-3-il]etanonas com cloridrato de hidroxilamina em rendimentos de 42% e 58%, respectivamente. Finalmente, as estruturas dos novos espiro heterociclos foram determinadas com o auxílio e aplicação simultânea de experimentos de RMN de 1H, 13C{1H}, 19F, difração de raios-X em monocristais, Espectrometria de Massas e cálculos DFT e, a sua pureza comprovada por Análise Elementar ou por Espectrometria de Massas de Alta Resolução (HRMS).
15

Towards Achieving Higher Product Selectivity by Controlling Photoreactivity

George, Sobiya January 2021 (has links)
No description available.
16

Riluzole elevates GLT-1 activity and levels in striatal astrocytes

Carbone, M., Duty, S., Rattray, Marcus January 2012 (has links)
No / Drugs which upregulate astrocyte glutamate transport may be useful neuroprotective compounds by preventing excitotoxicity. We set up a new system to identify potential neuroprotective drugs which act through GLT-1. Primary mouse striatal astrocytes grown in the presence of the growth-factor supplement G5 express high levels of the functional glutamate transporter, GLT-1 (also known as EAAT2) as assessed by Western blotting and (3)H-glutamate uptake assay, and levels decline following growth factor withdrawal. The GLT-1 transcriptional enhancer dexamethasone (0.1 or 1 muM) was able to prevent loss of GLT-1 levels and activity following growth factor withdrawal. In contrast, ceftriaxone, a compound previously reported to enhance GLT-1 expression, failed to regulate GLT-1 in this system. The neuroprotective compound riluzole (100 muM) upregulated GLT-1 levels and activity, through a mechanism that was not dependent on blockade of voltage-sensitive ion channels, since zonasimide (1 mM) did not regulate GLT-1. Finally, CDP-choline (10 muM-1 mM), a compound which promotes association of GLT-1/EAAT2 with lipid rafts was unable to prevent GLT-1 loss under these conditions. This observation extends the known pharmacological actions of riluzole, and suggests that this compound may exert its neuroprotective effects through an astrocyte-dependent mechanism.

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