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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.
251

Evaluation de la radiothérapie vectorisée à l’aide de nanocapsules lipidiques chargées en rhénium-188 pour le traitement du glioblastome : investigation des modalités d’administrations locales / Evaluation of nanovectorized radiotherapy using 188Re-lipid nanocapsules for glioblastoma treatment : investigation on local deliveries’ modalities.

Cikankowitz, Annabelle 10 December 2015 (has links)
Les glioblastomes sont des tumeurs gliales de hautgrade qui restent incurables de nos jours. Le traitement recommandé (résection chirurgicale suivie d’un traitement de radiothérapie externe associé à la chimiothérapie) conduit à une augmentation de la médiane de survie des patients de quelques mois. De nouvelles stratégies notamment dans le champ des nanomédecines véhiculant un radioélément (émetteur ou ) ont été évaluées en clinique. La première partie,après avoir dressé l’état des lieux des technologies utilisées dans ce domaine, rend compte des critères importants à prendre en compte que sont le choix du radioélément, les modalités d’administration et les vecteurs utilisés. Elle se conclut par une présentation des études précliniques en cours dont l’utilisation de nanovecteurs encapsulant un radioisotope : lesLNC188Re-SSS. La deuxième partie illustre l’application thérapeutique sur un modèle murin de xénogreffe et montre une éradication de la tumeur initiale suite à un protocole personnalisé d’injection fractionnée par convection-enhanced delivery. Elle décrit également la distribution des LNC ainsi que les effets directs des radiations sur les cellules tumorales (cellules géantes atypiques, supposées polyploïdes), accompagnés par un infiltrat inflammatoire (immunité innée). Une évaluation complémentaire sur modèle murin GL261 a été réalisée et constitue la troisième partie de cette thèse. Le transfert de ces résultats à l’application clinique pourrait être facilité par le recours à un modèle canin de gliome spontané homologue à celui de l’homme, dont ce travail prépare l’utilisation, dans le but de valider les procédures d’injection intracérébrales automatisées. / High grade glial brain tumors are defined as glioblastomas. Nowadays, they are incurable. The current therapeutic purposal (surgical resection, external radiotherapy and chemotherapy) doesn’t extend the patients median survival time up to a few months. Newstrategies as nanomedicines loaded with a radionuclide( or  emitter) have been evaluated in clinical trials. As tate of the art of this domain’s technologies is described in a first part which analyses the important criteria to take account in vectorized radiotherapy like the radionuclides, the route of administration and the vectors used. Then, it is concluded with a presentation of preclinical on going studies as the use of nanovectors loaded with a radioisotope : the LNC188Re-SSS. The second part illustrates the therapeutical strategy application on a xenograft mice model. The data showan eradication of the tumor mass of treated mice withthe personalized convection-enhanced delivery offractionated radiotherapy. Furthermore, it describes the LNC distribution and the direct radiation effects on tumor cells (atypical giant cells, polyploïdy) supported by an inflammatory infiltration (innate immune effectors). An evaluation on the GL261 mice model has been realized and concerns the third part of this thesis. In perspectives, the transfer of these data to clinical trials could be facilitated thanks to the dog spontaneous glioma model. This tumor share characteristics with the human neoplasma. Finally, this work will aim to validate the automated intracranial injection procedures.
252

Methods for Asymmetric Olefination Reactions; Development and Application to Natural Product Synthesis

Strand, Daniel January 2006 (has links)
This thesis deals with the development and application of methods for asymmetric olefinations, in particular Horner-Wadsworth-Emmons (HWE) reactions, in the synthesis of certain natural products. Relying on asymmetric HWE reactions to access key building blocks, two natu-ral products, pyranicin and pyragonicin, were synthesized from common late intermediates. The utility of the HWE reactions is highlighted through a desymmetrization of a meso-dialdehyde as well as a stereoconvergent reaction sequence employing the sequential use of a HWE parallel kinetic resolution fol-lowed by a Pd-catalyzed allylic substitution to convergently transform a race-mate to a single stereoisomer of the product. Methodological extensions of these syntheses include a divergent synthesis of 2,3,6-substituted tetrahydropyran derivatives and application of Zn-mediated asymmetric alkynylations to install key stereocenters. Synthetic studies directed towards a more complex target, mucocin, employing a triply convergent strategy, have also been performed. Expedient and reliable routes to three key fragments were developed, as well as methodology to access to all nine stereocenters. The fragment coupling to assemble the oligonuclear core still remains a challenge, however. Key features of the synthesis include the formation of two fragments from a common precursor derived from an asymmetric HWE desymmetrization, Zn-mediatedated asymmetric alkynylations, a stereoselective oxa-Michael cyclization dependent on a simultaneous protective group migration and a one-pot procedure for the synthesis of a TBS protected iodohydrin from a terminal epoxide. An investigation of the possibilities for developing a transition metal catalyzed asymmetric olefination using a chiral Re-complex is outlined. An enantioen-riched BINAP-Re complex was synthesized and characterized by X-ray. An efficient protocol for the olefination of functionalized aldehydes employing this catalyst was developed, but gave racemic products in two attempted kinetic resolutions of racemic substrates, most likely due to a reaction pathway proceeding via a non-metal associated phosphonium ylide. / QC 20100921
253

Synthèse et caractérisation de composés fluorés pour le piégeage de fluorures gazeux / Synthesis and characterization of nanofluorides for the reactivity of gaseous fluorides

Clarenc, Romain Pierre 05 November 2010 (has links)
Ce travail porte sur la synthèse et la caractérisation de fluorures à base d’alcalins, d’alcalinoterreuxet de terres rares et sur la réactivité de ces composés vis-à-vis de ReF6 pour lapurification de UF6. L’étude traite dans un premier temps de la synthèse de fluorures tels queKMgF3, MgF2 et CaF2 en couplant une voie solvothermale assistée par micro-ondes et uneétape de fluoration à partir de fluor élémentaire (F2). Les techniques de caractérisationutilisées mettent notamment en avant le caractère basique au sens de Lewis de ces composéset la possibilité de contrôler leur surface spécifique et leur taux d’oxygène, à l’origine dessites basiques, via la température de fluoration (F2) en phase gaz. Dans un second temps, lasolution solide Ce1-xZrxF4 à base de Ce4+ et Zr4+ a été obtenue par fluoration directe d’oxydesmixtes à partir de fluor élémentaire dilué. L’étude par DRX et RMN du 19F montre laprésence d’une solution solide pour des compositions voisines de x=0,5. Enfin, la réactivité deReF6 et UF6 sur KMgF3, MgF2 et CaF2 montre que KMgF3 est un très bon candidat pour lapurification de UF6 vis-à-vis de ReF6, qui dépend à la fois de paramètres intrinsèques auxfluorures divisés (surface spécifique, taux d’oxygène, basicité, cations mis en jeu…) maisaussi du procédé de purification (température, temps de contact). / This work deals with the synthesis and characterization of alkali, alkali-earth and rare earthbased fluorides and the reactivity of the latter with ReF6 for UF6 purification. In a first part,we focused our attention on the synthesis of KMgF3, MgF2 and CaF2 high surface area metalfluorides coupling both microwave assisted solvothermal process and a fluorination step withelemental fluorine (F2). The higher the surface area, the higher the oxygen rate. Thesenanofluorides exhibit Lewis basic character. In a second part, several compositions of theCe1-xZrxF4 solid solution were synthesized by direct fluorination of mixed oxides usingelemental fluorine (F2). XRD an 19F NMR characterizations show the occurence of a newsolid solution for compositions close to x=0.5. Finally, the reactivity between ReF6/UF6 andKMgF3, MgF2 and CaF2 leads to conclude that KMgF3 is the best candidate for thepurification of UF6. This study indicates that the purification depends on several parameters :intrinsic parameters of the divided fluorides (surface area, oxygen rate, basicity, cations…)and parameters directly related to the process (temperature, contact time).
254

Desenvolvimento de metodos de medida de atividade empregando sistemas de coincidencia para radionuclideos que desintegram pela dupla emissao beta sup(-) - beta sup(+) / captura eletronica - aplicacao na padronizacao do sup(192)Ir, sup(152)Eu e sup (186) Re

HILARIO, KATIA A.F. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:47:00Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:10:33Z (GMT). No. of bitstreams: 1 07614.pdf: 6594444 bytes, checksum: 0bd72d3764d638a649ad00b67ff5aa44 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
255

Desenvolvimento de metodos de medida de atividade empregando sistemas de coincidencia para radionuclideos que desintegram pela dupla emissao beta sup(-) - beta sup(+) / captura eletronica - aplicacao na padronizacao do sup(192)Ir, sup(152)Eu e sup (186) Re

HILARIO, KATIA A.F. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:47:00Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:10:33Z (GMT). No. of bitstreams: 1 07614.pdf: 6594444 bytes, checksum: 0bd72d3764d638a649ad00b67ff5aa44 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
256

Preparo e avaliação dos complexos de derivados de tiossemicarbazonas com(67/68 Ga) gálio, [99mTc] tecnécio e (111In)índio, como potenciais agentes para detecção de tumores / Preparation and evaluation of the thiosemicarbazone derivative complexes (67/68Ga)gallium, [99mTc]technetium and (111In)Indium as potential agents for tumor detection

Alyne Eloise Lafratta 06 June 2016 (has links)
Nas últimas décadas a medicina nuclear tornou-se uma grande aliada no auxílio ao diagnóstico de doenças e também para o tratamento do câncer. Parte deste sucesso está relacionada à constante pesquisa e desenvolvimento de novos radiofármacos. Uma classe de molécula que vem se mostrando promissora para o tratamento de tumores, tanto na sua forma orgânica quanto na forma de complexos organo-metálicos, é a tiossemicarbazona e seus derivados, os quais também podem formar complexos com radioisótopos metálicos dando origem a radiofármacos para diagnóstico e terapia. Neste trabalho foram preparados complexos com o ligante benzil-5-hidroxi-3-metil-5-fenil-4,5-diidro-1H-pirazol-1-carboditionato (H2bdtc) com os radioisótopos [99mTc]tecnécio, (67/68Ga)gálio e (111In)índio, e foram avaliados a pureza radioquímica, Log P e a estabilidade na presença de L-cisteína, L-histidina, soro albumina humana (SAH) e plasma de sangue humano; também foram avaliadas a taxa de captação dos radiofármacos in vitro em células de melanoma murino B16F10 e TM1M, além da avaliação da captação ex vivo e in vivo utilizando camundongos C57B/6 inoculados com as duas linhagens tumorais. Com o [99mT]tecnécio foram obtidos dois complexos diferentes, dependendo da concentração do PBS na solução, sendo que em um deles foi possível confirmar sua estrutura como [[99mTc]O(bdtc)(Hbdtc)] a partir do complexo de rênio [ReO(bdtc)(Hbdtc)], o outro complexo de [99mTc]tecnécio, bem como de (67/68Ga)gálio e (111In)índio não tiveram a estrutura caracterizada. A eficiência de marcação dos complexos foi superior a 90 %, com Log P maior que 1 para os complexos [[99mTc]O(bdtc)(Hbdtc)], [[99mTc]-bdtc] e [67/68Ga-bdtc] e 0,9 para [111In-bdtc]. Todos os complexos se mostraram com boa estabilidade na presença de L-cisteína e L-histidina, principalmente na primeira hora de incubação, mas não o foram na presença de SAH e plasma. A captação in vitro dos complexos em células B16F10 e TM1M variou entre 0,6 % e 1,8 %, e nos estudos de biodistribuição ex vivo foi obesrvada intensa e persistente captação hepática e no baço, superando 90 %, e captação no tumor variando de 0,2 % a 3 %, enquanto que nas imagens in vivo não foi possível observar de forma uma adequada captação nos tumores a ponto de permitir o uso como agente de diagnóstico. Os resultados permitem concluir que os complexos de derivados tiossemicarbazonas podem formar complexos com diferentes metais, mas novos derivados devem ser preparados para tentar melhorar o desempenho nos sistemas biológicos. Os experimentos com animais foram aprovados pela Comissão de Ética em Pesquisa da Faculdade de Medicina - USP, processo 372/12 / In recent decades, nuclear medicine has been used as diagnostic agent for disease and for the treatment of cancer. Part of this success is related to the constant research and development of new radiopharmaceuticals. Thiosemicarbazone and their derivatives have proven to be promising agent for the treatment of tumors, both in its organic form or as organo-metallic complexes. Also, they can to form complexes with metal radioisotopes giving radiopharmaceuticals for diagnosis and therapy. In this work we prepared complex of benzyl-5-hydroxy-3-methyl-5-phenyl-4,5-dihydro-1H-pyrazol-1-carboditionato (H2bdtc) with radioisotopes [99mTc]technetium (67/68Ga)gallium and (111In)indium and the radiochemical purity, Log P and stability in the presence of L-cysteine, L-histidine, human serum albumin (HSA) and human blood plasma were assessed; also were assessed the in vitro uptake rate of radiopharmaceuticals in murine melanoma cells B16F10 and TM1M, besides the evaluation of ex vivo uptake and in vivo using C57Bl/6 mice inoculated with both tumor lines. With [99mT] technetium two different complexes were obtained, depending on the concentration of the PBS in the solution, and one of them was had its structure to confirm as [[99mTc]O(bdtc)(Hbdtc)] from the standard rhenium complex [ReO(bdtc)(Hbdtc)], the other [99mTc] echnetium complex as well as (67/68Ga)gallium and (111In)indium not have characterized the structure. The labeling efficiency of compleos was higher than 90%, with log P higher than 1 for the complexes [[99mTc]O(bdtc)(Hbdtc)], [[99mTc]-bdtc] and [(67/68Ga)-bdtc] and 0.9 to [111In-bdtc]. All the complexes showed good stability in the presence of L-cysteine and L-histidine, especially in the first hour of incubation, but not in the presence of HSA and plasma. The uptake in vitro complexes in B16F10 and TM1M cells varied between 0.6% and 1.8%, and in ex vivo biodistribution studies was obesrvada intense and persistent liver uptake and spleen, exceeding 90%, and tumor uptake in changing from 0.2% to 3%, while in vivo imaging was not possible to observe a properly uptake in tumors, not allowing to use these molecules as a diagnostic agent. The results indicate that the thiosemicarbazone derivative complex can give complexes with different metals, but new derivatives should be prepared to try to improve performance in biological systems. The animal experimentation was approved by Comissão de Ética em Pesquisa da Faculdade de Medicina - USP, proccess 372/12
257

Využití hmotnostní spektrometrie a dalších analytických technik pro analýzu rheniových komplexů / Utilization of mass spectrometry and other analytical techniques for analysis of rhenium complexes

Vaňátková, Petra January 2016 (has links)
Rhenium complexes coordinated with suitable organic ligand gain increased interest in radiopharmaceutical medicine. Besides suitable radiological properties given by a metal ion itself, detailed knowledge of overall chemical properties of formed complexes, namely their exact structures, chemical stabilities and possible degradation pathways are essential pre-requisites for their clinical application. Selected rhenium complexes with pyrogallol 2,3-dihydroxynaphthalene and catechol as strongly bound ligands were prepared by a reaction of tetrabutylammonium tetrachlorooxorhenate with twofold molar excess of ligand in presence of various amount of triethylamine. The structures of formed complexes and their consequent reaction products were estimated by means of mass spectrometry with electrospray ionization. The kinetics of reactions in course of complex formation and consequent decomposition were primarily followed by UV- Vis absorption spectra measurement, complemented by single or continuous electrospray mass spectrometry analyses. Optimized HPLC and CZE procedures were utilized for monitoring of the composition of reaction mixtures in course of Re complex formation and for purity check of prepared complexes. Semi-preparative HPLC mode was succesfully utilized for isolation and final purification of...
258

Využití hmotnostní spektrometrie pro analýzu biologicky aktivních látek / Utilization of mass spectrometry for analysis of biologically active compounds

Kaliba, David January 2018 (has links)
This PhD thesis provides a commented set of four publications. These publications are focused on capillary electrophoresis, liquid chromatography, and UV/Vis spectrometry used to study complexes of rhenium with aromatic ligands. The methods of mass spectrometry with soft ionization techniques, 1 H and 13 C nuclear magnetic resonance, and infrared spectrometry were used for structural characterization of the individual complexes. The complexes were synthetized in reactions of the rhenium precursor tetrabutylammonium tetrachlorooxorhenate with the corresponding ligand under both aerobic and anaerobic conditions. In the course of the research, it was revealed that the prepared complexes (with Re in the oxidation number +V and +VI) are unstable and their oxidation numbers change to another more stable form (Re+VII ). Sub-projects which were successfully implemented during the research were as follows:  Design and successful realization of the process of synthesis of selected rhenium complexes with aromatic ligands 1,2-dihydroxybenzene, 1,2,3-trihydroxybenzene, and 2,3-dihydroxynaphthalene in reactions with and without air access, and their structural characterization by ESI-MS, APPI- MS, LDI-MS, ESI-MS/MS, NMR, and IR.  ESI-MS SRM and UV/Vis time studies of the behaviour of primary rhenium complexes...
259

Teoretická studie vlivu spin-orbitální interakce na spektra a fotofyziku rheniových komplexů / Theoretical study of spin-orbit coupling on spectra and photophysics of rhenium complexes

Heydová, Radka January 2017 (has links)
Title: Theoretical study of spin-orbit coupling on spectra and photophysics of rhenium complexes Author: RNDr. Radka Heydová Department: Physical and Macromolecular Chemistry Supervisor: Ing. Stanislav Záliš, CSc., JHI AS CR, v.v.i. Supervisor's e-mail address: stanislav.zalis@jh.inst-cas.cz Abstract: Relativistic effects, especially spin-orbit coupling (SOC), play an essential role in transition metal chemistry and SOC treatment is indispensable for a correct theoretical description. To demonstrate the importance of SOC, the energies and oscillator strengths of vertical transitions for a series of [ReX(CO)3(2,2'-bipyridine)] (X = Cl, Br, I) and [Re(imidazole)(CO)3(1,10-phenanthroline)]+ complexes were calculated in the spin-free (SF) and spin-orbit (SO) conceptual frameworks. Two different computational approaches were adopted: SO-MS-CASPT2 where SOC was added a posteriori using a configuration interaction model (SO-RASSI), and the approximate perturbative SO-TD-DFT method. Relativistic effects were included via the two-component Douglas-Kroll-Hess transformation and the zeroth-order regular approximation in the former and the latter technique, respectively. The SF (i.e. accounting only for the scalar relativistic effects) and SO results from both methods were compared with each other and to available...
260

Vers des assemblages de complexes métalliques oligonucléaires, servant d’antenne solaire au niveau moléculaire

Chartrand, Daniel 12 1900 (has links)
Les fichiers additionnels sont les données cristallographiques en format CIF. Voir le site de la Cambridge Crystallographic Data Centre pour un visualiseur: http://www.ccdc.cam.ac.uk / Ce projet de recherche vise l’élaboration de systèmes métallosupramoléculaires artificiels imitant le processus naturel de la photosynthèse. Idéalement, ces systèmes seraient capables de fournir l’énergie et la séparation de charge nécessaire pour catalyser des réactions à transfert multiélectroniques, tel que l’hydrolyse de l’eau ou la réduction du gaz carbonique. La réalisation d’un tel système catalytique créerait une source d’énergie renouvelable, sous forme d’énergie chimique, crée directement à partir de l’énergie solaire. Le système envisagé, schématisé sous la forme d’une antenne, possède trois parties distinctes. Tout d’abord, des chromophores forment un état excité en captant l’énergie de la lumière visible du soleil. Vient ensuite un centre de liaison qui lie tous les chromophores et qui collecte l’énergie de cet état excité à travers un transfert d’électron. Cet électron est de nouveau transféré vers la dernière partie, un centre réactionnel catalytique. Cet assemblage permet de créer une séparation de charge entre le chromophore et le centre réactionnel qui sont séparés par le centre de liaison, évitant ainsi la recombinaison de charge. Le projet se focalise sur la synthèse, la caractérisation et l’application en photocatalyse d’assemblages chromophore–centre de liaison–catalyseur. Tout d’abord, une étude de chromophores à base de fluorène et de rhénium a été effectuée dans le but d’évaluer le transfert électronique entre ces deux composants. Ensuite, des centres de liaisons à base de dimère de rhodium tétraamidinate ont été créés et étudiés afin d’établir leurs caractéristiques photophysiques et électrochimiques. Puis un d’entre eux a été assemblé avec des chromophores de rhénium, créant ainsi des espèces moléculaires discrètes contenant d’un à quatre chromophores. Et pour finir, ces assemblages ont été combinés avec un catalyseur à base de cobalt, puis ont été testés dans des expériences de photoproduction d’hydrogène. Cette dernière partie a requis l’élaboration d’un photoréacteur qui est aussi décrite en détail dans cet ouvrage. / This research project involves synthetic metallosupramolecular systems developed to mimic the natural process of photosynthesis. Ideally, these systems would be able to provide the energy and the charge separation needed to catalyze multielectron-transfer reactions, such as water-splitting or carbon dioxide reduction. The realization of such a catalytic system would create a renewable energy source, in the form of chemical energy, created directly from solar energy. The system envisioned has three distinct parts in the form of an antenna. First of all, chromophores go into an excited state, while capturing the visible light energy of the Sun. Then comes a hub which binds all the chromophores and collects this excited state energy through an electron transfer. This electron is then transferred again to the last part, a catalytic reaction center. This assembly creates a charge separation between the chromophore and the reaction center which are separated by the hub, thus avoiding the recombination of charge. The project focuses on the synthesis, characterization and application in photocatalysis of chromophore-hub-catalyst assemblies. First of all, a study of fluorene and rhenium based chromophores was made to assess the electronic transfer between these two components. Then, tetraamidinate rhodium dimer based hubs have been created and studied in order to establish their photophysical and electrochemical characteristics. Then one of these assemblies was formed with chromophores of rhenium, thus creating discrete molecular species containing one to four chromophores. And finally, these assemblies were combined with a cobalt-based catalyst and were tested for hydrogen photoproduction. The latter required the development of a photoreactor which is also described in detail in this thesis.

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