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Análise da Incidência de Mutações no Gene HEXA na População Judaica Brasileira - Avaliação da Importância de um Programa Preventivo da Doença de Tay-Sachs / Frequency of HEXA mutations among the Brazilian Ashkenazi Jewish population - Evaluation of the importance of a screening program for Tay-Sachs diseaseRozenberg, Roberto 19 December 2000 (has links)
A doença de Tay-Sachs (DTS) é uma doença neurodegenerativa, de herança autossômica recessiva, que se manifesta a partir do sexto mês de vida. Crianças afetadas desenvolvem degeneração física e mental intensa, levando à morte até os 5 anos de idade. Não há atualmente cura ou tratamento disponível. Na população judaica, 1 em cada 31 indivíduos é portador da DTS, e a incidência da doença (aproximadamente 1 em cada 4.000 nascimentos) é cerca de 100 vezes maior nesta do que em outras populações. O advento do diagnóstico pré-natal para a DTS e o concomitante desenvolvimento de programas de detecção e orientação de heterozigotos da DTS em populações de judeus Ashkenazitas, iniciados em massa desde 1970, levaram a uma diminuição de 90% da incidência da doença nesta população. Estes programas são realizados em Israel, EUA e no Canadá, na população francocanadense. Três mutações no gene HEXA, codificador da sub-unidade ? da enzima hexosaminidase A, são responsáveis por 98% dos casos da DTS na população judaica Ashkenazita. Esse fato possibilita a utilização de um teste de DNA para a identificação de portadores da DTS nesta população. Segundo o censo do IBGE de 1991, a população judaica no Brasil é de 86.416 indivíduos. Este trabalho visou analisar a necessidade e a aceitação de um programa de detecção e orientação de portadores da DTS nesta população. Em particular, procurou-se (1) estabelecer a freqüência das 3 principais mutações causadoras da DTS na população judaica brasileira; (2) avaliar a reação de indivíduos desta população à proposta de um programa de triagem de portadores da DTS, com o objetivo de orientação para casais em risco de terem crianças afetadas. Este estudo foi realizado em escolas judaicas de ensino médio, em São Paulo e no Rio de Janeiro, seguindo o modelo canadense. Dentre 581 alunos (>=16 anos) que assistiram palestras informativas, 404 participaram da pesquisa, indicando uma taxa de participação de 70%. De acordo com os dados dos formulários de consentimento, aproximadamente 65% dos cromossomos analisados eram de origem judaica Ashkenazita. A análise das 3 mutações comuns no gene HEXA nestes 404 indivíduos detectou 8 portadores da DTS (7 da mutação InsTATC1278 e 1 de IVS12+1). Assim, a freqüência de portadores na amostra foi de 1 em cada 51 indivíduos. Considerando somente os cromossomos de origem judaica Ashkenazita, nossos dados indicam que a freqüência de portadores da DTS na amostra é de 1 em cada 33 indivíduos. As freqüências encontradas são equivalentes àquelas descritas em outras populações judaicas (P>0,05). Baseando-se nestes dados, concluí-se que justifica-se a implementação de um programa de identificação e orientação de portadores da DTS na população judaica brasileira. A contemplação dos diversos aspectos éticos envolvidos são parte essencial deste programa. / Tay-Sachs disease (TSD) is an autossomal recessive disease of lysossome storage characterized by progressive nervous degeneration. Children affected by TSD manifest first symptoms around 6 months and die before 5 years of age. TSD is caused by mutations in the HEXA gene, coding for the ? subunit of the hexosaminidase A enzyme. In the absence of the enzyme, its substrate, GM2 ganglioside, accumulates in the neurons of the central nervous cortex. Late onset TSD (chronic form) is a rare variant phenotype with appearance of first symptoms during the second or third decade of life. In the Ashkenazi jewish population, 1 in every 31 individuals is a TSD carrier. The disease incidence (1 in every 4.000 newborns) is 100 times higher in this population. The advent of pre-natal diagnosis for TSD and the development of preventive screening programs massively adopted by Ashkenazi jewish populations led to a 90% decrease in the disease incidence in this group. Three mutations in the HEXA gene are responsible for 98% of the disease incidence in Ashkenazi jews. This lead to the establishment of a DNA test for detection of TSD carriers in this population. The brazilian Ashkenazi jewish populations is around 100.000 individuals. This work aimed to establish the need and the acceptance of a screening program for this population. Specifically, it established the frequency of the 3 most common TSD mutations in a sample of the brazilian jewish population and evaluated the reaction of the community to the offer of a preventive program. This work was undertaken in jewish senior high-school students, in São Paulo and Rio de Janeiro, following the canadian preventive model. From 581 students (>=16 years old) that attended educational sessions, 404 volunteered to the test, indicating a 70% participation rate. According to the data of the consent form, approximately 65% of the chromosomes were associated to Ashkenazi jewish ancestry. The molecular analysis of the 3 most common mutations in the HEXA gene from the 404 participants detected 8 carriers (7 of InsTATC1278 and 1 of IVS12+1), thus indicating a carrier frequency of 1/51. In the Ashkenazi fraction, the estimated carrier frequency is 1 in 33 individuals. Both frequencies are similar to those described for other jewish communities (P>0,05). Based in this findings, it was concluded that the implementation of a screening program for TSD in the brazilian jewish population is feasible. The ethical aspects involved are an essential part of such a program.
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Análise da Incidência de Mutações no Gene HEXA na População Judaica Brasileira - Avaliação da Importância de um Programa Preventivo da Doença de Tay-Sachs / Frequency of HEXA mutations among the Brazilian Ashkenazi Jewish population - Evaluation of the importance of a screening program for Tay-Sachs diseaseRoberto Rozenberg 19 December 2000 (has links)
A doença de Tay-Sachs (DTS) é uma doença neurodegenerativa, de herança autossômica recessiva, que se manifesta a partir do sexto mês de vida. Crianças afetadas desenvolvem degeneração física e mental intensa, levando à morte até os 5 anos de idade. Não há atualmente cura ou tratamento disponível. Na população judaica, 1 em cada 31 indivíduos é portador da DTS, e a incidência da doença (aproximadamente 1 em cada 4.000 nascimentos) é cerca de 100 vezes maior nesta do que em outras populações. O advento do diagnóstico pré-natal para a DTS e o concomitante desenvolvimento de programas de detecção e orientação de heterozigotos da DTS em populações de judeus Ashkenazitas, iniciados em massa desde 1970, levaram a uma diminuição de 90% da incidência da doença nesta população. Estes programas são realizados em Israel, EUA e no Canadá, na população francocanadense. Três mutações no gene HEXA, codificador da sub-unidade ? da enzima hexosaminidase A, são responsáveis por 98% dos casos da DTS na população judaica Ashkenazita. Esse fato possibilita a utilização de um teste de DNA para a identificação de portadores da DTS nesta população. Segundo o censo do IBGE de 1991, a população judaica no Brasil é de 86.416 indivíduos. Este trabalho visou analisar a necessidade e a aceitação de um programa de detecção e orientação de portadores da DTS nesta população. Em particular, procurou-se (1) estabelecer a freqüência das 3 principais mutações causadoras da DTS na população judaica brasileira; (2) avaliar a reação de indivíduos desta população à proposta de um programa de triagem de portadores da DTS, com o objetivo de orientação para casais em risco de terem crianças afetadas. Este estudo foi realizado em escolas judaicas de ensino médio, em São Paulo e no Rio de Janeiro, seguindo o modelo canadense. Dentre 581 alunos (>=16 anos) que assistiram palestras informativas, 404 participaram da pesquisa, indicando uma taxa de participação de 70%. De acordo com os dados dos formulários de consentimento, aproximadamente 65% dos cromossomos analisados eram de origem judaica Ashkenazita. A análise das 3 mutações comuns no gene HEXA nestes 404 indivíduos detectou 8 portadores da DTS (7 da mutação InsTATC1278 e 1 de IVS12+1). Assim, a freqüência de portadores na amostra foi de 1 em cada 51 indivíduos. Considerando somente os cromossomos de origem judaica Ashkenazita, nossos dados indicam que a freqüência de portadores da DTS na amostra é de 1 em cada 33 indivíduos. As freqüências encontradas são equivalentes àquelas descritas em outras populações judaicas (P>0,05). Baseando-se nestes dados, concluí-se que justifica-se a implementação de um programa de identificação e orientação de portadores da DTS na população judaica brasileira. A contemplação dos diversos aspectos éticos envolvidos são parte essencial deste programa. / Tay-Sachs disease (TSD) is an autossomal recessive disease of lysossome storage characterized by progressive nervous degeneration. Children affected by TSD manifest first symptoms around 6 months and die before 5 years of age. TSD is caused by mutations in the HEXA gene, coding for the ? subunit of the hexosaminidase A enzyme. In the absence of the enzyme, its substrate, GM2 ganglioside, accumulates in the neurons of the central nervous cortex. Late onset TSD (chronic form) is a rare variant phenotype with appearance of first symptoms during the second or third decade of life. In the Ashkenazi jewish population, 1 in every 31 individuals is a TSD carrier. The disease incidence (1 in every 4.000 newborns) is 100 times higher in this population. The advent of pre-natal diagnosis for TSD and the development of preventive screening programs massively adopted by Ashkenazi jewish populations led to a 90% decrease in the disease incidence in this group. Three mutations in the HEXA gene are responsible for 98% of the disease incidence in Ashkenazi jews. This lead to the establishment of a DNA test for detection of TSD carriers in this population. The brazilian Ashkenazi jewish populations is around 100.000 individuals. This work aimed to establish the need and the acceptance of a screening program for this population. Specifically, it established the frequency of the 3 most common TSD mutations in a sample of the brazilian jewish population and evaluated the reaction of the community to the offer of a preventive program. This work was undertaken in jewish senior high-school students, in São Paulo and Rio de Janeiro, following the canadian preventive model. From 581 students (>=16 years old) that attended educational sessions, 404 volunteered to the test, indicating a 70% participation rate. According to the data of the consent form, approximately 65% of the chromosomes were associated to Ashkenazi jewish ancestry. The molecular analysis of the 3 most common mutations in the HEXA gene from the 404 participants detected 8 carriers (7 of InsTATC1278 and 1 of IVS12+1), thus indicating a carrier frequency of 1/51. In the Ashkenazi fraction, the estimated carrier frequency is 1 in 33 individuals. Both frequencies are similar to those described for other jewish communities (P>0,05). Based in this findings, it was concluded that the implementation of a screening program for TSD in the brazilian jewish population is feasible. The ethical aspects involved are an essential part of such a program.
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The mechanochemical Scholl reaction – a solvent-free and versatile graphitization toolGrätz, Sven, Beyer, Doreen, Tkachova, Valeriya, Hellmann, Sarah, Berger, Reinhard, Feng, Xinliang, Borchardt, Lars 28 April 2020 (has links)
Herein, we report on the mechanochemical Scholl reaction of dendritic oligophenylene precursors to produce benchmark nanographenes such as hexa-peri-hexabenzocoronene (HBC), triangular shaped C60 and expanded C222 under solvent-free conditions. The solvent-free approach overcomes the bottleneck of solubility limitation in this well-known and powerful reaction. The mechanochemical approach allows tracking the reaction process by in situ pressure measurements. The quality of produced nanographenes has been confirmed by MALDI-TOF mass spectrometry and UV-Vis absorption spectroscopy. This approach paves the way towards gram scale and environmentally benign synthesis of extended nanographenes and possibly graphene nanoribbons suitable for application in carbon based electronics or energy applications.
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Studium mechanizmu a kinetiky koordinační polymerace hexa-1,5-dienu katalyzované fenoxyiminovým komplexem titanu a MAO / Study of mechanism and kinetics of hexa-1,5-diene polymerisation catalyzed by phenoxy-imine titanium complex and MAOŠevčík, Jan January 2008 (has links)
This diploma thesis is focused on study of polymerization of hexa-1,5-diene catalyzed by phenoxy-imine titanium dichloride (FI Ti) and methylaluminoxane (MAO) as cocatalyst. Effect of monomer concentration, polymerization temperature and cocatalyst/catalyst ratio on catalytic activity, molecular weights, polydispersities and particularly microstructure of prepared poly(hexa-1,5-diene) was studied. 1H NMR spectroscopy revealed that the poly(hexa-1,5-diene) microstructure contained methylene-1,3-cyclopentane (MCP) as well as vinyl tetramethylene (VTM) units. Kinetics of this polymerization was studied. Finally, copolymer of ethene and hexa-1,5-diene possessing incorporated pendant vinyl group was prepared.
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Modelagem e otimização de um robô de arquitetura paralela para aplicações industriais. / Modeling and optimization of a parallel architecture robot for industrial applications.Tartari Filho, Sylvio Celso 07 April 2006 (has links)
Este trabalho trata do estudo de robôs de arquitetura paralela, focando na modelagem e otimização dos mesmos. Não foi construído nenhum tipo de protótipo físico, contudo os modelos virtuais poderão, no futuro, habilitar tal façanha. Após uma busca por uma aplicação que se beneficie do uso de um robô de arquitetura paralela, fez-se uma pesquisa por arquiteturas viáveis já existentes ou relatadas na literatura. Escolheu-se a mais apta e prosseguiu-se com os estudos e modelagem cinemática e dinâmica, dando uma maior ênfase na cinemática e dinâmica inversa, esta última utilizando a formulação de Newton - Euler. Foi construído um simulador virtual em ambiente MATLAB 6.5, dotado de várias capacidades como interpolação linear e circular, avanço e uso de múltiplos eixos coordenados. Seu propósito principal é o de demonstrar a funcionalidade e eficácia dos métodos utilizados. Depois foi incorporado ao simulador um algoritmo de cálculo do volume de trabalho da máquina que utiliza alguns dados do usuário para calcular o volume, que pode ser aquele atrelado a uma postura em particular ou o volume de trabalho de orientação total. Algoritmos para medir o desempenho da máquina quanto à uniformidade e utilização da força dos atuadores foram construídos e também incorporados ao simulador, que consegue mostrar o elipsóide de forças ao longo de quaisquer movimentos executados pela plataforma móvel. Quanto à otimização, parte do ferramental previamente construído foi utilizado para que se pudesse chegar a um modelo de uma máquina que respeitasse restrições mínimas quanto ao tamanho e forma de seu volume de trabalho, mas ainda mantendo o melhor desempenho possível dentro deste volume. / This work is about the study of parallel architecture robots, focusing in modeling and optimization. No physical prototypes were built, although the virtual models can help those willing to do so. After searching for an application that could benefit from the use of a parallel robot, another search was made, this time for the right architecture type. After selecting the architecture, the next step was the kinematics and dynamics analysis. The dynamics model is developed using the Newton ? Euler method. A virtual simulator was also developed in MATLAB 6.5 environment. The simulator?s main purpose was to demonstrate that the methods applied were correct and efficient, so it has several features such as linear and circular interpolations, capacity to use multiple coordinate systems and others. After finishing the simulator, an algorithm to calculate the machine workspace was added. The algorithm receives as input some desired requirements regarding the manipulator pose and then calculates the workspace, taking into consideration imposed constraints. Lastly, algorithms capable to measure the manipulator?s performance regarding to its actuator and end-effector force relationship were also incorporated into the simulator that calculates the machine?s force ellipsoid during any movement, for each desired workspace point. For the optimization procedures, some previously developed tools were used, so that the resulting model was capable to respect some workspace constraints regarding size and shape, but also maintaining the best performance possible inside this volume.
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Thermisch härtende Polymerverbundmaterialien als Basis für neue Befestigungssysteme / Thermally curable polymeric composit material as a basis for new chemical fixing systemsPöhlmann, Milena 07 December 2006 (has links) (PDF)
Mit der Entwicklung und Einführung ökologischer Bauweise im Neubau sowie neuen Baustoffsystemen in Sandwichbauweise wird es zunehmend erforderlich, neue effektive Befestigungsvarianten zu entwickeln, die eine dauerhafte Fixierung auch unter sicherheitstechnischen Bestimmungen sowie aus Garantie- bzw. haftungsrechtlichen Gründen ermöglichen. Die aus der Praxis bisher bekannten chemischen Befestigungssysteme (Zweikomponentenverbundmörtel, Verbundankerpatronen) weisen hinsichtlich der Applikation unter bautechnischen Bedingungen noch einige Nachteile auf. Dazu gehören vor allem längere Aushärtungszeiten zur Realisierung der abschließenden Verbundfestigkeit, Inhomogenitäten im Verbund, der Einsatz toxischer Verbindungen und eine Limitierung der Applikationsmöglichkeiten in horizontalen und Überkopf-Einsatzbereichen sowie Hohlkammersystemen. Alle zuvor genannten Punkte haben bis jetzt die Nutzung solcher Verbundwerkstoffe als universale Anwendungsmöglichkeit verhindert. Ein neues chemisches Befestigungssystem, welches aus Novolak gehärteten mit Hexamethylentetramin (Hexa) und anorganischen Füllstoff besteht, wurde für Applikationen in Beton entwickelt. Das Bindemittel härtet bei der Temperaturzuführung aus. Die unkatalysierte Befestigungsmasse zeigt bei einer Temperatur zwischen 150-300 °C eine hohe Reaktivität. Die Vorteile dieses Systems sind die unbegrenzte Lagerfähigkeit der vorgemischten härtbaren Masse sowie die Gewährleistung einer homogenen Netzwerkstruktur im gesamten Verbund und sie ist frei von giftigen und flüchtigen Substanzen. Auf den Einsatz toxischer Substanzen wurde verzichtet. In dieser Arbeit wurde die Gesamtkinetik der Reaktion während des Aushärtungsprozesses dieser Polymerkomposite untersucht. Die DSC- (nicht-isothermen, isothermen) und MDSC-Untersuchungen haben sich als ein sicheres Verfahren zur Qualitätskontrolle des Aushärtezustands der Befestigungssysteme herausgestellt. Parallel zur nicht-isothermischen und isothermischen DSC wurden Leitfähigkeitsmessungen durchgeführt, um den Endpunkt der Aushärtungsreaktion zu bestimmen. / The development and introduction of ecological construction methods and the use of sandwich materials make it necessary to develop new fixing systems and technologies. Dealing with the application in concrete and other substrates commercial chemical fixing systems show some disadvantages up to date. Especially the rather long curing time in order to realize the final bond strength, inhomogenities in the composite, the partial use of toxic substances and application limits of such systems in horizontal direction as well as hollow section materials has so far prevented the use of such composites for all-purpose applications. A new chemical fixing system, which consists of hexamethylene tetramine (hexa) cured novolac and inorganic filler, was developed for application in concrete. It is applied by a thermo-curing procedure. The uncatalyzed curable mixture has a high reactivity at temperature between 150-300 °C. Compared with commercial chemical fixing systems, the premixed curable mass has many benefits. First it has a unique storage stability and second, it is free of toxic and volatile substances. Another important aspect is, it is self-foaming. In this study was investigated the overall kinetics of the reaction during the curing process of these polymer composites. An appropriate method for this experiment proved to be the DSC in isothermal and non-isothermal mode and MDSC. This turned out to be a safe quality control technique for these systems. Parallel to the non-isothermal and isothermal DSC conductivity measurements have been performed to determine the end point of the curing reaction.
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Modelagem e otimização de um robô de arquitetura paralela para aplicações industriais. / Modeling and optimization of a parallel architecture robot for industrial applications.Sylvio Celso Tartari Filho 07 April 2006 (has links)
Este trabalho trata do estudo de robôs de arquitetura paralela, focando na modelagem e otimização dos mesmos. Não foi construído nenhum tipo de protótipo físico, contudo os modelos virtuais poderão, no futuro, habilitar tal façanha. Após uma busca por uma aplicação que se beneficie do uso de um robô de arquitetura paralela, fez-se uma pesquisa por arquiteturas viáveis já existentes ou relatadas na literatura. Escolheu-se a mais apta e prosseguiu-se com os estudos e modelagem cinemática e dinâmica, dando uma maior ênfase na cinemática e dinâmica inversa, esta última utilizando a formulação de Newton - Euler. Foi construído um simulador virtual em ambiente MATLAB 6.5, dotado de várias capacidades como interpolação linear e circular, avanço e uso de múltiplos eixos coordenados. Seu propósito principal é o de demonstrar a funcionalidade e eficácia dos métodos utilizados. Depois foi incorporado ao simulador um algoritmo de cálculo do volume de trabalho da máquina que utiliza alguns dados do usuário para calcular o volume, que pode ser aquele atrelado a uma postura em particular ou o volume de trabalho de orientação total. Algoritmos para medir o desempenho da máquina quanto à uniformidade e utilização da força dos atuadores foram construídos e também incorporados ao simulador, que consegue mostrar o elipsóide de forças ao longo de quaisquer movimentos executados pela plataforma móvel. Quanto à otimização, parte do ferramental previamente construído foi utilizado para que se pudesse chegar a um modelo de uma máquina que respeitasse restrições mínimas quanto ao tamanho e forma de seu volume de trabalho, mas ainda mantendo o melhor desempenho possível dentro deste volume. / This work is about the study of parallel architecture robots, focusing in modeling and optimization. No physical prototypes were built, although the virtual models can help those willing to do so. After searching for an application that could benefit from the use of a parallel robot, another search was made, this time for the right architecture type. After selecting the architecture, the next step was the kinematics and dynamics analysis. The dynamics model is developed using the Newton ? Euler method. A virtual simulator was also developed in MATLAB 6.5 environment. The simulator?s main purpose was to demonstrate that the methods applied were correct and efficient, so it has several features such as linear and circular interpolations, capacity to use multiple coordinate systems and others. After finishing the simulator, an algorithm to calculate the machine workspace was added. The algorithm receives as input some desired requirements regarding the manipulator pose and then calculates the workspace, taking into consideration imposed constraints. Lastly, algorithms capable to measure the manipulator?s performance regarding to its actuator and end-effector force relationship were also incorporated into the simulator that calculates the machine?s force ellipsoid during any movement, for each desired workspace point. For the optimization procedures, some previously developed tools were used, so that the resulting model was capable to respect some workspace constraints regarding size and shape, but also maintaining the best performance possible inside this volume.
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The Interactions of Zinc Thiolate Complexes and Exogenous Metal Species: Investigations of Thiolate Bridging and Metal ExchangeAlmaraz, Elky 2009 May 1900 (has links)
Small molecule Zn(II) complexes containing N- and S- donor environments may
serve as appropriate models for mimicking Zn protein sites, and thus, their reactions
with heavy metal ions such as Pt(II) and W(0) may provide insight into possible adduct
formation and zinc displacement. To study such possible interactions between zinc
finger proteins and platinum-bound DNA, the ZnN2S2 dimeric complex, N,N?-bis(2-
mercaptoethyl)-1,4-diazacycloheptane zinc (II), [Zn-1?]2, has been examined for Znbound
thiolate reactivity in the presence of Pt(II) nitrogen ? rich compounds. The
reactions yielded Zn/Pt di- and tri- nuclear thiolate-bridged adducts and metalexchanged
products, which were initially observed via ESI-mass spectrometry (ESI-MS)
analysis of reaction solutions, and ultimately verified by comparison to the ESI-MS
analysis, 195Pt NMR spectroscopy, and X-ray crystallography of directly synthesized
complexes. The isolation of Zn-(?-SR)-Pt-bridged [(Zn(bme-dach)Cl)(Pt(dien))]Cl
adduct from these studies is, to our knowledge, the first Zn-Pt bimetallic thiolatebridged
model demonstrating the interaction between Zn-bound thiolates and Pt(II). Additional derivatives involving Pd(II) and Au(III) have been explored to parallel the
experiments executed with Pt(II).
The [Zn-1?]2 was then modified by cleavage with Na+[ICH2CO2]- to produce (N-
(3-Thiabutyl)-N?-(3-thiapentaneoate)-1,4-diazacycloheptane) zinc(II), Zn-1?-Ac or
ZnN2SS?O, and 1,4-diazacycloheptane-1,4-diylbis(3-thiapentanoato) zinc(II), Zn-1?-Ac2
or ZnN2S?2O2, monomeric complexes (where S = thiolate, S? = thioether). The [Zn-1?]2
di- and Zn-1?-Ac mono-thiolato complexes demonstrated reactivity towards labile-ligand
tungsten carbonyl species, (THF)W(CO)5 and (pip)2W(CO)4, to yield, respectively, the
[(Zn-1?-Cl)W(CO)4]- complex and the [(Zn-1?-Ac)W(CO)5]x coordination polymer.
With the aid of CO ligands for IR spectral monitoring, the products were isolated and
characterized spectroscopically, as well as by X-ray diffraction and elemental analysis.
To examine the potential for zinc complexes (or zinc-templated ligands) to
possibly serve as a toxic metal remediation agents, Zn-1?-Ac and Zn-1?-Ac2 were reacted
with Ni(BF4)2. The formation of Zn/Ni exchanged products confirmed the capability of
?free? Ni(II) to displace Zn(II) within the N-, S-, and O- chelate environment. The
Zn/Ni exchanged complexes were analyzed by ESI-MS, UV-visible spectroscopy, IR
spectroscopy of the acetate regions, and X-ray crystallography. They serve as
foundation molecules for more noxious metal exchange / zinc displacement products.
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Cu(I) catalyzed alkyne-azide cycloaddition as a synthetic tool for the preparation of complex C60 derivatives / La cycloaddition alcyne-azoture catalysée au cuivre (I) comme outil synthétique pour l'élaboration de dérivés complexe du C60Vartanian, Maida 05 January 2012 (has links)
La présente thèse décrit la synthèse de briques de base de fullerènes pour la préparation de dispositifs moléculaires photoactifs combinant C60 et porphyrines. La cycloaddition alcyne-azoture catalysée au cuivre (I) a été utilisée comme outil de synthèse pour la préparation des dérivés C60 complexes.L’utilité synthétique de synthons C60 a été montrée avec la préparation d’édifices moléculaires complexes présentant des propriétés spécifiques pour diverses applications. Ainsi, un système photoactif flexible combinant C60 et porphyrine a été synthétisé. Cependant la flexibilité de l’espaceur liant les sous-unités de ce composé conduit à des variations de structurales importantes et complique ainsi l’analyse des études photophysiques.Dans ce contexte, nous nous sommes proposé dans une première partie de la présente thèse de parfaitement contrôler l’orientation et la distance des différentes sous-unités au sein de systèmes C60-donneurs. Afin de répondre à ce besoin, nous avons construit une brique de base de C60 rigide ayant un groupe azoture aromatique. Ainsi, la réaction « click » avec un phénylacétylène conjugué au groupement donneur conduit à un espaceur rigide entre les deux sous-unités.La deuxième partie de ce travail a été consacrée à la synthèse d’hexa-adduits du C60 portant différents groupements fonctionnels. Une méthode de synthèse permettant de préparer des hexa-adduits du C60 fonctionnalisés a été mise au point au laboratoire.Cette stratégie a été modifiée et des composés de C60 comportant dix fonctions azotures et une fonction alcyne protégée ont été synthétisés; dans ce cas il est possible d’introduire dans un premier temps par une réaction click dix groupes fonctionnels. Et dans un second temps; après déprotection de la fonction alcyne, une seconde réaction de click permet alors de greffer un fonctionnel différent. / The present PhD thesis manuscript is focused on the use of fullerene building blocks for the preparation of photoactive molecular devices combining C60 and porphyrins. Cu(I) Catalyzed alkyne-azide cycloaddition was used as a synthetic tool for the preparation of complex C60 derivatives. Specifically, in the first part (Chapter II-B), a flexible fullerene-porphyrin triad has been developed and the photophysical studies were performed. The flexible linker between the fullerene core and the azide groups prevented any conformational control on the relative orientation and distance between the two photoactive subunits connected together. This prompted the development of an analogous building block in which the azide unit is directly connected to the bridging phenyl ring (Chapter II-C). In this way, the click reaction with porphyrin-alkyne derivatives give access to hybrid systems with a controlled relative orientation of the two moieties. This is of fundamental importance for a better understanding of the structural parameters affecting the electron and/or energy transfer kinetic in such dyads.In the second part (Chapter III), a fullerene hexaadduct scaffold is used to build up sophisticated multiporphyrin systems for various applications. The preparation of these multi-chromophoric ensembles relies on the click-click approach developed in our group.
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Thermisch härtende Polymerverbundmaterialien als Basis für neue BefestigungssystemePöhlmann, Milena 16 October 2006 (has links)
Mit der Entwicklung und Einführung ökologischer Bauweise im Neubau sowie neuen Baustoffsystemen in Sandwichbauweise wird es zunehmend erforderlich, neue effektive Befestigungsvarianten zu entwickeln, die eine dauerhafte Fixierung auch unter sicherheitstechnischen Bestimmungen sowie aus Garantie- bzw. haftungsrechtlichen Gründen ermöglichen. Die aus der Praxis bisher bekannten chemischen Befestigungssysteme (Zweikomponentenverbundmörtel, Verbundankerpatronen) weisen hinsichtlich der Applikation unter bautechnischen Bedingungen noch einige Nachteile auf. Dazu gehören vor allem längere Aushärtungszeiten zur Realisierung der abschließenden Verbundfestigkeit, Inhomogenitäten im Verbund, der Einsatz toxischer Verbindungen und eine Limitierung der Applikationsmöglichkeiten in horizontalen und Überkopf-Einsatzbereichen sowie Hohlkammersystemen. Alle zuvor genannten Punkte haben bis jetzt die Nutzung solcher Verbundwerkstoffe als universale Anwendungsmöglichkeit verhindert. Ein neues chemisches Befestigungssystem, welches aus Novolak gehärteten mit Hexamethylentetramin (Hexa) und anorganischen Füllstoff besteht, wurde für Applikationen in Beton entwickelt. Das Bindemittel härtet bei der Temperaturzuführung aus. Die unkatalysierte Befestigungsmasse zeigt bei einer Temperatur zwischen 150-300 °C eine hohe Reaktivität. Die Vorteile dieses Systems sind die unbegrenzte Lagerfähigkeit der vorgemischten härtbaren Masse sowie die Gewährleistung einer homogenen Netzwerkstruktur im gesamten Verbund und sie ist frei von giftigen und flüchtigen Substanzen. Auf den Einsatz toxischer Substanzen wurde verzichtet. In dieser Arbeit wurde die Gesamtkinetik der Reaktion während des Aushärtungsprozesses dieser Polymerkomposite untersucht. Die DSC- (nicht-isothermen, isothermen) und MDSC-Untersuchungen haben sich als ein sicheres Verfahren zur Qualitätskontrolle des Aushärtezustands der Befestigungssysteme herausgestellt. Parallel zur nicht-isothermischen und isothermischen DSC wurden Leitfähigkeitsmessungen durchgeführt, um den Endpunkt der Aushärtungsreaktion zu bestimmen. / The development and introduction of ecological construction methods and the use of sandwich materials make it necessary to develop new fixing systems and technologies. Dealing with the application in concrete and other substrates commercial chemical fixing systems show some disadvantages up to date. Especially the rather long curing time in order to realize the final bond strength, inhomogenities in the composite, the partial use of toxic substances and application limits of such systems in horizontal direction as well as hollow section materials has so far prevented the use of such composites for all-purpose applications. A new chemical fixing system, which consists of hexamethylene tetramine (hexa) cured novolac and inorganic filler, was developed for application in concrete. It is applied by a thermo-curing procedure. The uncatalyzed curable mixture has a high reactivity at temperature between 150-300 °C. Compared with commercial chemical fixing systems, the premixed curable mass has many benefits. First it has a unique storage stability and second, it is free of toxic and volatile substances. Another important aspect is, it is self-foaming. In this study was investigated the overall kinetics of the reaction during the curing process of these polymer composites. An appropriate method for this experiment proved to be the DSC in isothermal and non-isothermal mode and MDSC. This turned out to be a safe quality control technique for these systems. Parallel to the non-isothermal and isothermal DSC conductivity measurements have been performed to determine the end point of the curing reaction.
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