Kliknij ten link, aby zobaczyć inne rodzaje publikacji na ten temat: Se substitution.
Rozprawy doktorskie na temat „Se substitution”
Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych
Sprawdź 50 najlepszych rozpraw doktorskich naukowych na temat „Se substitution”.
Przycisk „Dodaj do bibliografii” jest dostępny obok każdej pracy w bibliografii. Użyj go – a my automatycznie utworzymy odniesienie bibliograficzne do wybranej pracy w stylu cytowania, którego potrzebujesz: APA, MLA, Harvard, Chicago, Vancouver itp.
Możesz również pobrać pełny tekst publikacji naukowej w formacie „.pdf” i przeczytać adnotację do pracy online, jeśli odpowiednie parametry są dostępne w metadanych.
Przeglądaj rozprawy doktorskie z różnych dziedzin i twórz odpowiednie bibliografie.
1
Vanessa, Rocha Andréa. "Substitution operators." Universidade Federal de Pernambuco, 2009. https://repositorio.ufpe.br/handle/123456789/7073.
Pełny tekst źródłaStreszczenie:
Made available in DSpace on 2014-06-12T18:28:46Z (GMT). No. of bitstreams: 2
arquivo4238_1.pdf: 678788 bytes, checksum: 1a19da235845c146881443f4bbcb79b9 (MD5)
license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5)
Previous issue date: 2009<br>Nós estudamos um novo tipo de processo estocástico a tempo discreto, que nós chamamos de processos de substituição. Como o tempo é discreto, nós podemos definir este processo através de um operador que transforma uma medida de probabilidade (em um certo espaço) em outra. Vale a pena notar que a maioria dos estudos de processos de partículas interagentes se baseia na suposição de que o conjunto de sítios, também chamado de espaço, não muda ao longo da interação. Existem apenas poucos trabalhos onde os sítios podem aparecer e desaparecer durante a realização do processo, e este trabalho é um deles. Considere então um conjunto finito não-vazio A chamado de alfabeto, cujos elementos são chamados de letras. Sequências finitas de letras são chamadas de palavras e o comprimento de uma palavra é o número de letras que existe nela. Os elementos de AZ (sequências bi-infinitas de letras) são chamados de configurações. Denotamos por M o conjunto de medidas de probabilidade invariantes por translação. Nós podemos definir um operador de substituição genérico como um operador de M em M que substitui cada ocorrência de uma palavra G (onde G precisa satisfazer uma certa condição) em uma configuração por outra palavra H com probabilidade ρ, onde ρ pertence a [0; 1], independentemente das outras ocorrências. A nossa maior contribuição é dada pela definição e estudo dos operadores de substituição em geral. O caso mais interessante do operador de substituição, na nossa opinião, é o caso em que G e H têm comprimentos diferentes; a própria definição do operador neste caso é não-trivial. De fato, foi preciso desenvolver uma teoria de aproximação de medidas por sequências de palavras para lidar com este caso. Uma dificuldade com este caso é que os operadores de substituição não são lineares. No entanto, foi possível provar que todos eles são finos, que nos parece ser a melhor propriedade depois da linearidade. Nós também provamos que todos os operadores de substituição são contínuos e nós utilizamos este fato para obter conclusões a respeito da existência de medidas invariantes por estes operadores, o que nos ajuda a estudar ergodicidade do processo de substituição. Por fim, nós esperamos que estas propriedades possam ser relacionadas com certas necessidades de ciências aplicadas
2
Martyn, R. J. "Ipso aromatic substitution." Thesis, University of Canterbury. Chemistry, 1985. http://hdl.handle.net/10092/7318.
Pełny tekst źródłaStreszczenie:
In the first part of this thesis the conformation and stereochemistry of a number of polychlorocyclohex-3-enones, formed by the reaction of chlorine in acetic acid and hydrochloric acid with polysubstituted phenols (or anilines), are discussed. Those polychlorocyclohex-3-enones with the H(Cl)CS or the Me(Cl)CS structural features were shown to exist in a twist-boat conformation with the CS-Cl bond in the flagpole orientation. In contrast, two polychlorocyclohex-3-enones with gem-dichloro substituents at C5, were shown to be conformationally mobile in solution. The alicyclic ring of two 4,4,5-trichlorocyclohex-2-enones were also shown to exist in twist-boat conformations, but with the CS-Cl bond in the equatorial orientation. A satisfactory correlation between the ¹H n.m.r. and infrared spectroscopic data and the known structures in the solid state indicates that these polychlorocyclohex-3-enones and polychlorocyclohex-2-enones adopt conformations in solution close to those observed in the solid state.
Extensive use of single-crystal X-ray structure analysis was made in the above structural studies; some thirteen structure analyses are reported in this thesis.
In the second part of this thesis are discussed the reactions of polysubstituted 2-methylphenols with chlorine in carbon tetrachloride in the presence of pyridine to give
6-chloro-6-methylcyclohexa-2,4-dienones. These 6-chloro-6-methylcyclohexa-2,4-dienones arise from ipso chlorine attack on the phenol ortho to the hydroxy function. It was shown that attack ipso to a methyl group occurred in preference to attack ipso to a chlorine atom. Where both ortho positions of the phenolic substrate are methyl substituted, the site of ipso chlorine attack is affected by the meta substituents.
In the third part of this thesis the additions of chlorine to 6-chloro-6-methylcyclohexa-2,4-dienones to give polychlorocyclohex-3-enones and polychlorocyclohex-2-enones are discussed. These addition reactions proceed by three distinct reaction mechanisms, 2,3-, 4,5- and 2,5-chlorine addition. The 2,3-chlorine addition reaction was shown to be powerfully acid-catalysed. In contrast, the 4,5- and 2,5-chlorine additions were shown to be only mildly acid-catalysed. Reaction mechanisms which accommodate these observations are discussed.
Finally, the formation of an acyclic pentachloro hex-3-enoic acid by the chlorination of 4-chloro-2-methyl-6-nitrophenol (130) in acetic acid and hydrochloric acid is described and a probable mode of formation suggested.
3
Parnjai, Jarungjit. "Behavioral service substitution." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II, 2013. http://dx.doi.org/10.18452/16725.
Pełny tekst źródłaStreszczenie:
Serviceevolution erlaubt es, einen Service durch einen anderen Service zu verfeinern oder zu ersetzen. Der Austausch durch einen anderen Service sollte garantieren, dass alle oder ausgewählte Partner des Originalservices erhalten bleiben. In dieser Arbeit entwickeln wir einen Ansatz welcher einem Serviceentwickler helfen soll, Analyse- und Syntheseaufgaben für den Serviceaustausch so durchzuführen, dass jeder Partner eines gegebenen Services beim Austausch erhalten bleibt. Wir modellieren einen Kontrollfluss eines Services als Beschreibung der Reihenfolge von asynchron kommunizierenden Ereignissen mittels eines impliziten ungeordneten Nachrichtenspeichers. Weiterhin studieren wir den Verhaltensaspekt von korrekter Interaktion zwischen Services und konzentrieren uns auf zwei Varianten von Verklemmungsfreiheit als Korrektheitskriterien von Serviceersetzung. Der wichtigste Beitrag ist ein Ansatz zur Charakterisierung jedes möglichen Austausches eines gegebenen Services. Die zentrale Idee dieses Ansatzes ist eine systematische Untersuchung der Verbindung zwischen einem Service und all seiner Partner bzgl. eines gegebenen Korrektheitskriteriums. Wir nutzen diese Verbindung um von einem gegebenen Service einen kanonischen Partner und einen kanonischen Austausch bzgl. aller Partner zu synthetisieren. Ein Service welcher den kanonischen Austausch eines gegebenen Services verfeinert wird als Austausch des gegebenen Services angesehen, wenn die Menge all seiner Partner jeden Partner des gegebenen Services enthält. Mit dem kanonischen Austausch eines gegebenen Services identifizieren wir die Menge der möglichen austauschenden Services eines gegebenen Services bei der jeder exakt die gleichen Partner wie der gegebene Service hat. Einige Ergebnisse dieser Arbeit fundieren auf früheren Arbeiten zu Austausch und Korrektheit von Services und können daher mit diesen verbunden werden um schwierigere Analyse- und Syntheseaufgaben für den Serviceaustausch durchzuführen.<br>Service evolution allows one service to be refined into or substituted by another service. Substituting one service by another service should guarantee to preserve all or selected partners of the original service. In this thesis, we develop an approach that shall assist a service designer, such as a domain expert, to perform analysis and synthesis tasks on service substitution. We model a control flow of services that describes the ordering of asynchronously communicating events over an implicit unordered message buffer. We study the behavioral aspect of correct interaction between services and concentrate on two variants of deadlock freedom as correctness criteria of service substitution. The major contribution of this thesis is an approach for characterizing the set of all substitutes for a given service. We systematically investigate the relationship between a service and all its partners under a given correctness criterion and employ this relationship to synthesize from a given service its canonical partner and its canonical substitute with respect to all partners. A service that refines the canonical substitute for a given service is regarded as a substitute for the given service if the set of all its partners includes every partner of the given service. With the canonical substitute of a given service, we identify a specific subset of the set of all substitutes for the given service, each of which has exactly the same set of partners as that of the given service. Parts of the results in this thesis have been established upon previous works on service substitution and correctness of services. Consequently, we can also combine our results with the related existing techniques to perform more sophisticated analysis and synthesis tasks on service substitution.
4
Anfinsen, Jarle. "Making substitution matrices metric." Thesis, Norwegian University of Science and Technology, Department of Computer and Information Science, 2005. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-9237.
Pełny tekst źródłaStreszczenie:
<p>With the emergence and growth of large databases of information, efficient methods for storage and processing are becoming increasingly important. The existence of a metric distance measure between data entities enables efficient index structures to be applied when storing the data. Unfortunately, this is often not the case. Amino acid substitution matrices, which are used to estimate similarities between proteins, do not yield metric distance measures. Finding efficient methods for converting a non-metric matrix into a metric one is therefore highly desirable. In this work, the problem of finding such conversions is approached by embedding the data contained in the non-metric matrix into a metric space. The embedding is optimized according to a quality measure which takes the original data into account, and a distance matrix is then derived using the metric distance function of the space. More specifically, an evolutionary scheme is proposed for constructing such an embedding. The work shows how a coevolutionary algorithm can be used to find a spatial embedding and a metric distance function which try to preserve as much of the proximity structure of the non-metrix matrix as possible. The evolutionary scheme is compared to three existing embedding algorithms. Some modifications to the existing algorithms are proposed, with the purpose of handling the data in the non-metric matrix more efficiently. At a higher level, the strategy of deriving a metric distance function from a spatial embedding is compared to an existing algorithm which enforces metricity by manipulating the data in the non-metric matrix directly (the triangle fixing algorithm). The methods presented and compared are general in the sense that they can be applied in any case where a non-metric matrix must be converted into a metric one, regardless of how the data in the non-metric matrix was originally derived. The proposed methods are tested empirically on amino acid substitution matrices, and the derived metric matrices are used to search for similarity in a database of proteins. The results show that the embedding approach outperforms the triangle fixing approach when applied to matrices from the PAM family. Moreover, the evolutionary embedding algorithms perform best among the embedding algorithms. In the case of the PAM250 scoring matrix, a metric distance matrix is found which is more sensitive than the mPAM250 matrix presented in a recent paper. Possible advantages of choosing one method over another are shown to be unclear in the case of matrices from the BLOSUM family.</p>
5
Maletti, Andreas. "Pure and O-Substitution." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-99193.
Pełny tekst źródłaStreszczenie:
The basic properties of distributivity and deletion of pure and o-substitution are investigated. The obtained results are applied to show preservation of recognizability in a number of surprising cases. It is proved that linear and recognizable tree series are closed under o-substitution provided that the underlying semiring is commutative, continuous, and additively idempotent. It is known that, in general, pure substitution does not preserve recognizability (not even for linear target tree series), but it is shown that recognizable linear probability distributions (represented as tree series) are closed under pure substitution.
6
Harriss, Edmund Orme. "On canonical substitution tilings." Thesis, Imperial College London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.408103.
Pełny tekst źródła
7
Dolby, David. "Propositions, substitution and generality." Thesis, University of Reading, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.500543.
Pełny tekst źródła
8
Maletti, Andreas. "Pure and O-Substitution." Technische Universität Dresden, 2006. https://tud.qucosa.de/id/qucosa%3A26215.
Pełny tekst źródłaStreszczenie:
The basic properties of distributivity and deletion of pure and o-substitution are investigated. The obtained results are applied to show preservation of recognizability in a number of surprising cases. It is proved that linear and recognizable tree series are closed under o-substitution provided that the underlying semiring is commutative, continuous, and additively idempotent. It is known that, in general, pure substitution does not preserve recognizability (not even for linear target tree series), but it is shown that recognizable linear probability distributions (represented as tree series) are closed under pure substitution.
9
Mallet-Bricout, Blandine. "La substitution de mandataire." Paris 2, 1998. http://www.theses.fr/1998PA020072.
Pełny tekst źródłaStreszczenie:
La substitution de mandataire, operation a trois personnes reglementee par le code civil a l'article 1994, a lieu lorsque le mandataire confie a un tiers (mandataire substitue) tout ou partie de la mission qu'il a recue de son mandant, le substitue agissant alors au nom et pour le compte de ce dernier. Le legislateur de 1804 ne s'est interesse qu'a la responsabilite du mandataire principal a l'egard du mandant et a l'action ouverte au mandant directement a l'encontre du substitue. Mais bien des zones d'ombre subsistent, alors meme que la substitution de mandataire est tres frequemment mise en oeuvre dans des domaines varies. L'etude du triple rapport juridique unissant les protagonistes a cette operation s'impose, d'autant plus que la substitution de mandataire n'a jamais ete etudiee dans son ensemble. Or il apparait indispensable de s'interroger sur la justesse et l'opportunite de regles ou analyses considerees comme acquises, et de soulever plusieurs questions jusqu'a present delaissees : l'influence du droit commun du mandat sur le regime de la substitution de mandataire, celle de la jurisprudence sur les regles posees en matiere de responsabilite, l'existence d'hypotheses de substitution dans l'ignorance du mandant ou du mandataire substitue, ou encore la nature et le regime de l'action instauree par l'article 1994 alinea 2 en faveur du mandant, puis accordee au mandataire substitue par la jurisprudence. Un autre interet de cette etude est de decouvrir la veritable nature juridique de la substitution de mandataire. Pour de nombreux auteurs, le contrat de substitution est sans aucun doute un sous-mandat. Cette qualification, que la jurisprudence ne rejette pas expressement, est discutable. La substitution de mandataire presente un fort particularisme: loin de se glisser dans le moule d'une qualification juridique exclusive, sous-contrat ou cession de contrat notamment, elle se revele doublement originale. Du point de vue de la theorie de la representation, elle ne peut etre confondue avec le mandat de droit commun, bien qu'il s'agisse sans aucun doute d'une forme de representation. Du point de vue de la theorie generale des obligations, elle doit etre analysee en une operation + multi-qualifiable ;, qui recoit des qualifications distinctes en fonction des hypotheses pratiques envisagees<br>Subangency, a three persons operation which is ruled by the french civil code (art. 1994), takes place when the agent gives to the subagent a part of or all the mission he received from the principal. The subagent is therefore acting in the name and on behalf of the principal. Legislator in 1804 was only interested in the question of the agent liability to the principal (art. 1994 al. 1) and in the action granted to the principal directly against the subagent (art. 1994 al. 2). But many questions are subsisting even when subagency is very frequent in various legal areas. As subagency has never been studied in the whole in french law, it is necessary to examine the treble link between the protagonists of this operation. Expediency and accuracy of the rules or analysis considered secured must be discussed, and different questions till now deserted must be mooted : influence of agency common law on subagency regulations, that of jurisprudence on rules about liability, existence of hypothesis of subagency in the ignorance of principal or of subagent, nature and regulations of the action established by article 1994 al. 2 in favor of principal and then opened to subagent by jurisprudence. Another concern of this study is to discover the true juridical nature of subagency. For many authors part, subagency contract with no doubt is a + sous-mandat ;. This qualification, not expressly denied by judges, can be discussed. Subagency presents a great particularism : it can not answer to an exclusive and classical qualification, sub-contract or transfer of contract, it is revealed singular in a double manner. Regarding to agency theory, it can't be confounded with agency common law, even though it is an operation about representation. Regarding to general theory of bonds, it must be analysed as a + multiqualifiable ; operation, which receives different qualifications depedent of the practical subagency suppositions
10
Mallet-Bricout, Blandine. "La substitution de mandataire /." Paris : Éd. Panthéon-Assas : diff. LGDJ, 2000. http://catalogue.bnf.fr/ark:/12148/cb372052144.
Pełny tekst źródła
11
Marshall, Jonathan. "Heteroatom Substitution within Indenofluorenes." Thesis, University of Oregon, 2016. http://hdl.handle.net/1794/20402.
Pełny tekst źródłaStreszczenie:
The inclusion of atoms other than carbon into the framework of polycyclic conjugated hydrocarbons can have profound effects on the properties of the resultant compounds. Substitution of acenes with nitrogen-, oxygen-, and sulfur-containing rings has long been used as a strategy to alter the HOMO and LUMO energy levels of a compound and direct the solid-state morphology. In this thesis, I present my work in extending heteroatom substitution into the class of compounds known as indenofluorenes.
Chapter I serves as an overview of indenofluorenes and related compounds with a special focus on the redox properties of these materials. Chapter II covers the synthesis and characterization of two selenophene-containing indenofluorene analogues. Chapter III discloses a new synthetic method for the preparation of unsymmetrical indenofluorenes and discusses the unusual reactivity of the dione precursors. Chapter IV is a comprehensive study of indacenodibenzothiophenes. This chapter investigates how heteroatom substitution affects the antiaromaticity of the indacene core and presents a detailed optoelectronic, computational, solid-state and materials study of a series of indacenodibenzothiophene derivatives. Chapter V presents my work towards the synthesis of the final unknown indenofluorene isomer, indeno[1,2-a]fluorene. Appendices A and B discuss my work done as part of Professor Shih-Yuan Liu’s research group at the start of my graduate career.
This dissertation includes previously published and unpublished coauthored material.<br>10000-01-01
12
Murshed, Mohammad Mangir. "Gallium substitution in alumosilicate sodalites." [S.l. : s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=975134388.
Pełny tekst źródła
13
Kennedy, R. J. "Copper-promoted nucleophilic aromatic substitution." Thesis, University of Kent, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.355148.
Pełny tekst źródła
14
Hartley, Joseph P. "Indium catalysed electrophilic aromatic substitution." Thesis, University of Bath, 2002. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.760785.
Pełny tekst źródła
15
Pamukoglu, Güliz. "Import-substitution industrialization in Turkey." Thesis, Massachusetts Institute of Technology, 1990. http://hdl.handle.net/1721.1/69265.
Pełny tekst źródła
16
Chen, Cheng S. M. Massachusetts Institute of Technology. "Security of substitution-permutation network." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/101582.
Pełny tekst źródłaStreszczenie:
Thesis: S.M., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2015.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 43-44).<br>In this thesis, we study the security of a block cipher design called substitution-permutation network (SPN). We prove that when S-box is chosen uniformly at random as a permutation, the resulting SPN is a strong pseudorandom permutation even against an adversary having oracle access to that S-box. We then examine some special cases of SPN for a fixed S-box and prove two special cases of SPN inspired by AES are 2-wise independent.<br>by Cheng Chen.<br>S.M.
17
Rodriguez, Medina Inmaculada Concepcion. "Studies on oxidative aromatic substitution." Thesis, University of Sussex, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390923.
Pełny tekst źródła
18
PERROTEY, ANNE. "Substitution nucleophile et lithiation d'arenetricarbonylchrome." Paris 6, 1996. http://www.theses.fr/1996PA066325.
Pełny tekst źródłaStreszczenie:
Dans la premiere partie de ce travail, nous avons etudie la regioselectivite de l'addition d'anions stabilises de nitriles ou d'esters sur le complexe de la benzophenone et de ses derives dans le but de synthetiser un precurseur du ketoprofene. Nous avons ensuite envisage une autre voie de synthese du ketoprofene: une substitution nucleophile ipso d'un atome d'halogene. Dans un premier temps, nous avons etudie la regioselectivite de la lithiation du complexe de la benzophenone protegee par un acetal (premiere etape avant l'halogenation). Dans la deuxieme partie, nous avons tente de lithier diatereoselectivement le complexe du phenol ayant sa fonction hydroxyle protegee par une copule chirale. Nous avons obtenu un complexe du phenol-tricarbonylchrome substitue en ortho pour un groupement phosphore chiral. Nous avons ensuite synthetise des complexes diastereoisomeres fonctionnalises par une fonction alcene en ortho d'une fonction aldehyde protegee par un animal chiral
19
Wilson, Gregory Arthur. "Labor Substitution in U.S. Manufacturing." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/31108.
Pełny tekst źródłaStreszczenie:
This paper presents a translog model designed to estimate the elasticity of substitution between capital, non-production workers, and production workers using U.S. manufacturing data for the period 1988 to 1997. The elasticity of substitution estimates derived from the translog model suggest that production workers and capital are substitutes, as well as non-production and production workers. Although the estimates do not provide conclusive evidence regarding the degree of substitutability between non-production workers and capital, they do indicate that the degree of substitutability between production workers and capital is greater than it is between non-production workers and capital.<br>Master of Arts
20
Gaymard, Alexandre. "Étude et suivi de la résistance des virus influenzae A aux inhibiteurs de la neuraminidase." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSE1135/document.
Pełny tekst źródłaStreszczenie:
Les virus influenzae sont des pathogènes importants ayant un impact à la fois écologique et en santé publique humaine. En effet chez l’Homme, ces virus sont responsables de la grippe, qu’elle soit saisonnière, pandémique ou zoonotique. Face à ces infections très peu d’options thérapeutiques sont disponibles : seuls les inhibiteurs de neuraminidases (INA) sont recommandés par l’OMS mais des résistances ont été décrites. Les substitutions H274Y, E119V et R292K sont les substitutions de résistance retrouvées le plus fréquemment dans les neuraminidases des virus influenzae humains. Dans notre travail, l’étude des résistances aux INA a été organisée autour de deux axes, d’une part via le suivi clinique et biologique de la résistance chez les patients et d’autre part via l’étude de l’impact des substitutions de résistance dans des neuraminidases aviaires. La surveillance de ces résistances au sein du CNR des virus des infections respiratoires a permis la caractérisation du génome de virus influenza A(H1N1)pdm09 dans un contexte d’excrétion chronique en présence d’un traitement par INA chez un patient atteint de déficit immunitaire combiné sévère mais aussi le développement et l’évaluation de la PCR digitale pour le diagnostic de la substitution H274Y des virus A(H1N1). Au niveau mécanistique, notre travail a permis l’analyse des substitutions (H274Y, R292K, E119V±I222L) sur l’ensemble des sous-types de neuraminidases des virus influenzae A. La substitution H274Y se retrouve préférentiellement dans les N1 mais est responsable d’une diminution de la sensibilité à l’oseltamivir pour toutes les neuraminidases du groupe 1 (N1, N4, N5 et N8). La substitution E119V entraine une diminution de la sensibilité à l’oseltamivir variable en fonction des neuraminidases avec un impact plus important pour les N2, N7, N9 et N5. De plus l’association des substitutions E119V+I222L entraine un effet synergique sur le phénotype de résistance à l’oseltamivir. Enfin la substitution R292K entraine une diminution de la sensibilité à tous les INA dans toutes les neuraminidases du groupe 2 (N2, N3, N6, N7 et N9). La production d’une N9 recombinante portant la substitution R292K a montré un impact majeur de la substitution sur l’activité enzymatique. Un développement technologique toujours en cours au laboratoire va nous permettre d’aller plus loin dans l’analyse des mécanismes qui sous-tendent l’apparition de ces résistances<br>Influenza viruses are important human pathogens that are responsible for flu, whether seasonal, pandemic or zoonotic. Very few therapeutic options are available against these pathogens and neuraminidase inhibitors (NAI) are the only antiviral agents recommended by the WHO for treatment and prophylaxis of influenza virus infections. NAI resistance has already been described and the H274Y, E119V and R292K neuraminidase substitutions are the most frequently encountered substitutions responsible for oseltamivir resistance. During this work, we focused the NAI resistance study around two main objectives: first, we monitored clinical and biological resistance in treated patients and then we studied the impact of substitutions responsible for NAI resistance using avian neuraminidases. For NAI resistance monitoring, viral genomic diversity of a child's influenza A(H1N1)pdm09 was characterized in the context of a severe combined immunodeficiency and a chronic viral excretion despite antiviral treatment. For a better detection of H274Y substitution in A(H1N1) influenza viruses, a digital droplet PCR was developed and evaluated. At a more fundamental level, resistance substitutions (H274Y, R292K, E119V ± I222L) were analysed using all neuraminidase subtypes of influenza A viruses. To summarize, H274Y substitution is preferentially isolated in N1 but also decreases oseltamivir susceptibility in all group 1 neuraminidases (N1, N4, N5 and N8). The E119V substitution impact on oseltamivir susceptibility depends on the neuraminidase and decreases oseltamivir susceptibility especially within N2, N7, N9 and N5. Moreover, the E119V+I222L substitutions has a synergistic effect on oseltamivir resistance profile. The R292K substitution decreases all NAI susceptibility for all group 2 neuraminidases (N2, N3, N6, N7 and N9). The production of a recombinant N9 bearing the R292K substitution allows to highlight the substitution impact on the sialidasic activity. Development of new technological tools are still in progress to allow a more accurate analysis of the mechanisms that underlie the NAI resistance
21
Tasdemir, Ozlem. "Currency And Asset Substitution In Turkey." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/2/1002369/index.pdf.
Pełny tekst źródłaStreszczenie:
This study investigates the determinants and effects of currency and asset substitution in Turkey using quarterly data from 1987:1 to 2002:4. The empirical results from the application of Johansen procedure to a four-variable
system containing currency-asset substitution proxy (M2Y/M2)), real income, real exchange rate, and ratchet effect proxy (past peak values of the depreciation of
the real exchange rate) suggest the presence of a single cointegration vector among the variables. The results further suggest the endogeneity of the degree of currency substitution for the parameters of the cointegration vector. According to the theory consistent and data-acceptable long-run relationship between the variables, there is a strong ratchet (hysteresis) effect in currency-asset
substitution in Turkey. The study contains also the policy implications of both currency substitution and the ratchet effect arising from real exchange rate change shocks in the Turkish economy.
22
Lee, Jeong-Yup. "Lattice substitution systems and model sets." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ60145.pdf.
Pełny tekst źródła
23
Hofmann, Robert Carl Werner. "Die Grenzen der Substitution im Arbeitszeitgesetz /." Lohmar ; Köln : Eul, 2007. http://deposit.d-nb.de/cgi-bin/dokserv?id=2969052&prov=M&dok_var=1&dok_ext=htm.
Pełny tekst źródła
24
Wyper, Joshua Stephen. "The atonement of Christ penal substitution /." Theological Research Exchange Network (TREN), access this title online, 2006. http://dx.doi.org/10.2986/tren.042-0143.
Pełny tekst źródła
25
Nguyen, Quang. "Reinventing Aromatic Substitution: A Novel Look." TopSCHOLAR®, 2013. http://digitalcommons.wku.edu/theses/1292.
Pełny tekst źródłaStreszczenie:
Electrophilic aromatic substitution (EAS) and directed ortho-metalation (DoM) involve the direct substitution of an arene hydrogen. A major drawback involving EAS is the necessity for harsh forcing conditions for the reaction to proceed. Catalysts such as Lewis acids FeBr3 and AICI3 for the introduction of halogens and acyl groups, respectively, are each highly toxic and corrosive. Textbook preparations of aryl iodides classicaly involved the use of iodine and nitric acid. This approach affords only modest yields and does not provide regiospecific substitution of most substituted aromatics because most contain ortho/para directors which afford mixtures of isomers. The novelty of our procedure for the synthesis of the iodinated aromatics is twofold in that regiospecific para-iodination is observed and hydrocarbon media are utilized. Hydrocarbon media are less hazardous and greener than media used for halogenations reported in literature. This procedure always yields derivatives regiospecifically substituted para to an electron donating substituent. Moreover, this method eliminates the need to use hazardous oxidative catalysts. DoM is a reaction regiospecifically substitute an arene hydrogen at the ortho position. The media used in DoM reactions are less hazardous than those required for a variety of EAS reactions. The only problem for this reaction is use of extremely strong bases, alkyllithium reagents, which are known to be air and water sensitive. However, the DoM reaction does eliminate the need to separate ortho/para isomer mixtures so that only a single product is generated. The metalation yields predominantly products regiospecifically substituted ortho-to the direcing metalating group (DMG). With our deficiency catalysis concept and subsequent purificaion methods, relatively pure ortho-lithiated intermediates have been prepared. The study of catalysts/promoters on the derivatization of these intermediates is anticipated to be extremely insightful. For this study, we have shown that highly selective, efficient ortho-lithiation can be achieved by deficiency catalysis utilizing n-BuLi as the only strong metalating base.
26
Beard, Collen Alana. "Rubredoxin cobalt substitution and crystallization attempts." Thesis, Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/29863.
Pełny tekst źródła
27
Murphy, Nicholas Patrick. "Radical aromatic cyclisation and substitution reactions." Thesis, University of Warwick, 2008. http://wrap.warwick.ac.uk/2286/.
Pełny tekst źródłaStreszczenie:
This dissertation is divided into five chapters. Chapter One consists of an introduction to radical cyclisation and rearrangement reactions. Chapter Two investigates the reactions of substituted arylsulfonamides 278a-l with copper bromide and an amine ligand-TPA. This reaction involves an alkyl radical generated from the copper (I) bromide/TPA complex, which can then undergo a 1,5- ipso attack onto the sulfonamide leading to a cyclohexadienyl radical intermediate. Re-aromatisation and extrusion of sulfur dioxide leads to an amidyl radical intermediate. This can undergo either cyclisation back onto the aromatic ring to give the 6-substituted oxindole 336, or reduction from H-atom abstraction by the solvent leading to rearranged amides. A minor product identified as a 5-substituted oxindole 333 may be formed from direct radical cyclisation onto the sulfonamide followed by extrusion of sulfur dioxide. An unambiguous synthesis of 333 was obtained through the Stollé method in order to rigorously identify this product. For completion, the rearranged amide 280e was also unambiguously synthesised from known literature sources. It has been shown that the selectivity towards either rearrangement or cyclisation is dependent upon the solvent used and temperature. For example, toluene induces excellent selectivity towards cyclisation (to furnish oxindoles), while using dichloromethane (DCM) induces a greater selectivity towards rearranged amides. Chapter Three explores the effects of varying the alkyl chain length on the nitrogen atom on selectivity, while keeping both the aryl group and initiator the same. It has been shown that selectivity towards the rearrangement (or decrease in cyclisation) occurred when the alkyl chain was increased from N-butyl to N-dodecyl. In addition a similar solvent effect on selectivity was observed as discussed in Chapter 3, notably relatively more rearranged amide was produced with DCM and oxindoles with toluene. Chapter four involves investigating the copper-mediated radical cyclisation of haloamides to give oxindoles directly. The final chapter consists of the experimental.
28
Stephen, J. A. "Co-substitution in novel hydroxyapatite materials." Thesis, University of Aberdeen, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.590972.
Pełny tekst źródłaStreszczenie:
Silicate substitution in hydroxyapatite (HA), with a substitution limit of ~5.2 wt%, has been shown previously to enhance the bioactivity of this material <i>in vivo</i>. The current study describes the substitution of greater levels of silicate <i>via </i>a coupled substitution of yttrium and silicate ions for calcium and phosphate ions, respectively. This was carried out using two different substitution mechanisms, and silicate levels of up to 11.25 wt% were incorporated; these compositions were characterised extensively. There was not a clear correlation between the surface properties of samples produced by the different mechanisms and the growth behaviour of MG-63 osteoblast-like cells, although there was a correlation with substitution mechanism. Following the success in increasing the level of silicate substitution in HA <i>via </i>the co-substitution of the Y<sup>3+</sup> ion, the synthesis of similar materials, but substituting another ion in place of Y<sup>3+</sup>, was attempted. Gadolinium was chosen for its similar size, but primarily because of its use in MRI contrast agents. Similar levels of silicate substitution to the Y<sup>3+</sup>/SiO<sub>4</sub><sup>4-</sup> co-substituted materials were achieved for both mechanisms. An MRI study showed improved contrast of the Gd<sup>3+</sup>/SiO<sub>4</sub><sup>4-</sup> co-substituted compositions compared to stoichiometric HA, which suggests that these new compositions may have clinical applications where bone repair and implant resorption could be monitored using MRI. Carbonate-substituted HA is the subject of the final part of this study. The effect of the synthesis route upon the resulting carbonate location within the lattice is examined. Since CHA can be synthesised to contain sodium ions as a co-substituted ion, or as a sodium-free composition, investigations were carried out to find a synthesis method for both types of composition.
29
Mugal, Carina Farah. "Nucleotide Substitution Patterns in Vertebrate Genomes." Doctoral thesis, Uppsala universitet, Evolutionsbiologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-198787.
Pełny tekst źródłaStreszczenie:
The rates and patterns at which nucleotide substitutions occur vary significantly across the genome sequence of vertebrates. A prominent example is the difference in the rate of evolution of functional sequences versus nonfunctional (neutrally evolving) sequences, which is explained by the influence of natural selection on functional sequences. However, even within neutrally evolving sequences there is striking variation in the rates and patterns of nucleotide substitutions. Unraveling the underlying processes that induce this variation is necessary to understand the basic principles of variation in neutral substitution profiles, which in turn is crucial for the identification of regions in the genome where natural selection acts. This research question builds the main focus of the present thesis. I have studied the causes and consequences of variation in different patterns of nucleotide substitutions. In particular, I have investigated substitutional strand asymmetries in mammalian genes and could show that they result from the asymmetric nature of DNA replication and transcription. Comparative analysis of substitutional asymmetries then suggested that the organization of DNA replication and the level of transcription are conserved among mammals. Further, I have examined the variation in CpG mutation rate among human genes and could show that beside DNA methylation also GC content plays a decisive role in CpG mutability. In addition, I have studied the signatures of GC-biased gene conversion and its impact on the evolution of the GC isochore structure in chicken. By comparison of the results in chicken to previous results in human I found evidence that karyotype stability is critical for the evolution of GC isochores. Finally, beside the empirical studies, I have performed theoretical investigations of substitution rates in functional sequences. More precisely, I have explored the temporal dynamics of estimates of the ratio of non-synonymous to synonymous substitution rates dN/dS in a phylogentic-population genetic framework.
30
McMurdo, J. "Electrophilic aromatic substitution using methoxyacetyl chloride." Thesis, University of East Anglia, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302997.
Pełny tekst źródła
31
Wainwright, Julie Ann. "Carbonyl substitution in platinum pentamethylcyclopentadienyl complexes." Thesis, University of Salford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245018.
Pełny tekst źródła
32
Talk, Ruaa. "Deprotonation-substitution of N-Boc-tetrahydroisoquinolines." Thesis, University of Sheffield, 2017. http://etheses.whiterose.ac.uk/19202/.
Pełny tekst źródłaStreszczenie:
Tetrahydroisoquinolines (THIQs) are found in a wide range of natural products and compounds with biological activity. This thesis describes the methodology of deprotonation‒substitution as an efficient route to 1-substituted THIQs and 3-substituted THIQs. This methodology was developed by using organolithium and organomagnesium chemistry. Firstly, methods were developed for the lithiation–substitution of tetrahydroisoquinolines by carrying out in situ ReactIR spectroscopic monitoring of deprotonation reactions. Moderate to high yields of products were obtained under the optimum reaction conditions. The lithiation‒substitutions of tetrahydroisoquinolines A were carried out. This chemistry was applied to a short synthesis of the alkaloids (±)-dysoxyline and (±)-crispine A. The lithiation–substitution of N-Boc-3-phenyltetrahydroisoquinoline B was also investigated. Lithiation was found to occur with approximately a 2:1 ratio at C-1 to C-3. NMR studies and DFT analysis were carried out in order to calculate the ratio of the two rotamers of B. Investigations have also focused on N-Boc-3-cyanotetrahydroisoquinoline and N-Boc-2-cyanopyrrolidine. High enantioselectivities of the forming products could be obtained from the sequence of deprotonation–substitution of these compounds at –104 ºC using magnesium bases. Altering the solvent was shown to have a large impact on the yield and enantioselectivity of the products.
33
Maritime, Abraham Aaron. "An efficient substitution model scheme evaluator." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/42750.
Pełny tekst źródłaStreszczenie:
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.<br>Includes bibliographical references (leaf 121).<br>by Abraham Aaron Maritime.<br>M.Eng.
34
Chan, Lax. "Continuous spectra for substitution-based sequences." Thesis, Open University, 2018. http://oro.open.ac.uk/53661/.
Pełny tekst źródłaStreszczenie:
This thesis is chiefly concerned with the continuous spectra of substitution-based sequences. First, motivated by a question of Lafrance, Yee and Rampersad [34], we establish a connection between the ‘root-N’ property and the corresponding sequences that satisfy it having absolutely continuous spectrum. Then we use the recent advances in Bartlett [10, 11] to show that the Rudin–Shapiro-like sequence has singular continuous spectrum, hence does not satisfy the root-N property. This gives a negative answer to the question raised by the authors in [34]. Secondly, we use the connection we establish between the root-N property and absolute continuity to create more substitution-based sequences that have absolutely continuous/Lebesgue spectrum. This is done by modifying Rudin’s original construction [44]. We show that the binary sequences (±1 sequences) from our modification also satisfy the root-N property and they are mutually locally derivable to the corresponding substitution sequences. This shows that the spectral properties of the substitution-based sequences are inherited from their binary counterpart. Finally, we generalise our construction using Fourier matrices. This leads to extending Rudin’s construction to sequences with complex coefficients. This approach allows us to generate substitution sequences of any constant length greater than or equal to two. We show explicitly in the length 3 and 4 cases that these systems exhibit Lebesgue spectrum, employing Bartlett’s algorithm from Chapter 3 and mutual local derivability.
35
Nair, Aruna. "Justifying claims based on unauthorised substitution." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:b985b154-fbdb-4c47-863d-b95369af461c.
Pełny tekst źródłaStreszczenie:
This thesis examines the doctrinal justification for the contingency of certain private law claims on tracing in English law. It argues that, contrary to the currently dominant model of tracing as an evidential process, aimed at resolving factual uncertainties, the tracing rules are best understood as normative in function. They strike a balance between preserving the autonomy of the defendant, while preventing her from exploiting the claimant's legally mandated vulnerability to the defendant's decisions to deprive him of rights. The rules distinguish among the different legal capacities of a person acquiring a right, and permit a stranger to the transaction to assert an entitlement to its product only in cases where the product is separable from the person of the defendant and where its acquisition involved the exercise of a legal power to deprive the claimant. On this basis, the thesis argues that claims contingent on tracing are better described as claims based on 'unauthorised substitution'. An unauthorised substitution occurs where A acquires a right in consideration for the valid exercise of a private legal power affecting B, in breach of a duty owed to B. Such an exercise of power can only take place in the context of a prior relationship of 'stewardship of assets', whereby A has a legal power to vary the legal rights of B with respect to some assignable right, owes B a duty in respect of the exercise of that power, and is able to validly exercise the legal power in breach of that duty. These relationships overlap with the categories of 'fiduciary duties' or 'property rights', but share additional and distinctive characteristics that justify the law's particular response to unauthorised substitution.
36
ASSELIN, THUILLIEZ CORINNE. "Le droit de substitution au canada." Lille 2, 1997. http://www.theses.fr/1997LIL2P050.
Pełny tekst źródła
37
Chabran, Isabelle. "La Négociation de substitution dans l'entreprise." Paris 1, 1986. http://www.theses.fr/1986PA010311.
Pełny tekst źródła
38
Guillaume, Bruno. "Un calcul de substitution avec etiquettes." Chambéry, 1999. http://www.theses.fr/1999CHAMS017.
Pełny tekst źródłaStreszczenie:
Le lambda-calcul est un formalisme simple et abstrait qui joue un role crucial dans l'etude des langages de programmation fonctionnelle et dans les assistants a la demonstration. L'operation de base du lambda-calcul (la beta-reduction) pose de nombreux problemes d'implementation, c'est pourquoi abadi, cardelli, curien et levy ont propose le lambda-sigma-calcul, dans lequel l'operation de beta-reduction est decomposee en operations plus elementaires en introduisant des substitutions explicites. De nombreux autres calculs avec substitutions explicites ont ete proposes. Le principal probleme est de trouver un tel calcul qui soit a la fois confluent sur les termes avec metavariables (mc) et qui preserve la forte normalisation du lambda-calcul (psn). Dans cette these, on montre que le lambda-se-calcul (un calcul propose par kamareddine et rios) n'a pas la psn. L'etude de la non psn dans lambda-sigma et dans lambda-se a permis d'obtenir le resultat principal de cette these, c'est-a-dire un nouveau calcul (nomme lambda-l) dont on montre qu'il possede les deux proprietes souhaitees. Il s'agit de l'un des premiers calculs qui possedent ces deux proprietes et qui simulent la beta-reduction pas a pas. Les techniques de preuve (pour la psn) sont nouvelles et ne ressemblent pas du tout aux preuves existantes pour des calculs sans composition de substitutions. Une partie de la preuve de psn, ainsi que les preuves de confluence locale ont ete verifiees par un programme caml.
39
KHOURZOM, RAMI. "Les complexes arenetricarbonylchrome : substitution nucleophile aromatique." Paris 6, 1990. http://www.theses.fr/1990PA066564.
Pełny tekst źródłaStreszczenie:
Les travaux realises au cours de cette these permettent d'illustrer les proprietes originales des complexes arenetricarbonylchrome. Les anions en alpha d'un groupement sulfonyle agissent sur des halogeno-benchrotrenes selon des substitutions nucleophiles aromatiques ipso, cine, tele-meta et tele-para. L'addition de l'anion secondaire sur les isomeres du fluoro- et chlorotoluenetricarbonylchrome est a la fois regio- et diastereoselective. La fluoration des chloro-benchrotrenes fournit les complexes resultant d'une coupure de la liaison carbone-chlore. Nous avons egalement mis au point l'addition nucleophile d'anions non carbones sur des complexes portant un groupement fluore. Ces anions sont l'amidure de sodium et le trifluoroethylate de sodium
40
Couapel, Morgane. "Droit, éthique et médecine de substitution." Amiens, 2006. http://www.theses.fr/2006AMIE0052.
Pełny tekst źródłaStreszczenie:
La médecine de substitution englobe les techniques fondées sur le traitement de l’homme par les éléments et produits du corps humain d’autrui. Cela concerne les greffes d’organes, de tissus et de cellules, l’assistance médicale à la procréation et le clonage. Le droit est nécessaire pour l’encadrer, mais il ne suffit pas à en obtenir une étude complète. Une approche pluridisciplinaire s’impose. La législation adoptée, révisée avec cinq années de retard, contribue à garantir le respect des principes de justice, de sécurité et de qualité dans l’utilisation du corps humain. Cette approche juridique nationale doit se conjuguer avec une approche supranationale et extra-législative, notamment éthique, religieuse et sociétale. Il est possible de manipuler le corps humain dans l’intérêt d’une tierce personne. Mais, il faut garantir le respect et la protection des personnes, tout en autorisant la réalisation de thérapeutiques salvatrices<br>Medicine by substitution includes therapeutics based on man’s treatment by elements and products of other people’s body. It concerns organs, tissues and cells transplantations, medically assisted reproduction and cloning. Law is necessary to provide a frame for it, but it is not enough to obtain a complete study of it. A pluridisciplinary approach is essential. The adopted legislation, revised after a five years’ delay, contributes to guarantee the respect of law, security and quality principles as far as using the human body is concerned. This legal and national approach must combine with a supranational approach and an extralegal approach, particularly in the fields of ethics, religion and society. It is possible to handle the human body in other people’s interest. But, it will have to guarantee the respect and the protection of persons, while authorizing the realization of saving therapeutics
41
Chudoba, Lubomír. "Generic Substitution: From Threat To Opportunity." Master's thesis, Vysoká škola ekonomická v Praze, 2011. http://www.nusl.cz/ntk/nusl-142296.
Pełny tekst źródłaStreszczenie:
The objective of this thesis is to identify factors, which are influencing pharmacists` choice of a particular drug in a situation when generic substitution can be offered to a patient, and to analyse the relative importance of these factors for the pharmacists. This study investigates such behavioural patterns of pharmacists operating within chain of pharmacies called Alphega. The research consists of 2 consecutive parts; Firstly, qualitative inquiry through depth-in interviews has been carried out in order to identify variables, which may shape pharmacist's choice. And subsequently, quantitative investigation has been performed for the purpose of assessing importance of each variable. The results of the research have finally been used to evaluate the strategy of antibiotic Augmentin produced by company GlaxoSmithKline.
42
Rae, Robert Lammie. "Substitution effects in intramolecular furan cycloadditions." Thesis, Heriot-Watt University, 2014. http://hdl.handle.net/10399/2829.
Pełny tekst źródłaStreszczenie:
The intramolecular Diels-Alder reaction of furan (IMDAF) provides a high degree of structural complexity in one step. However, reaction reversibility issues and the lower reactivity of furan in comparison to non-aromatic dienes prevent more widespread use of furan as a diene component in such reactions. Initial efforts to develop a new mode of organocatalysis which we hoped would facilitate IMDAF reaction was unfortunately unsuccessful, thus alternative means of IMDAF facilitation were investigated. For the first time, a comprehensive synthetic and computational study of the effect of halogen substitution on the IMDAF reaction has been undertaken. We have successfully demonstrated that halogenation of the furan moiety facilitates the IMDAF reaction (displaying increased reactivity to the non-halogenated analogue, regardless of halogen position), whereas dienophile halogenation hinders it. Additionally, careful selection of the position of the halogen on the furan can somewhat overcome the detrimental effect of having a halogen on the dienophile leading to highly functionalised cycloadducts with potential for further modification. Computational data produced by Martin Paterson and Justyna McKinlay support the idea that frontier molecular orbital effects cannot explain the experimental observations and we thus believe that the reactions are controlled by the interplay of three factors: positive charge stabilisation in the transition state and product, steric effects and a dipolar interaction term identified by the high level calculations. Finally, we have briefly demonstrated that nitro groups on the furan moiety also facilitate the IMDAF reaction whereas acyl groups appear to hinder the reaction. STEREOCHEMICAL ABSTRACT Any chiral compounds included in this thesis are racemic in nature. However, for clarity, such mixtures are schematically represented by drawings of only one of the enantiomers.
43
Logvinovich, Dmitry. "Anionic substitution in perovskite-type oxides." kostenfrei, 2008. http://d-nb.info/993937535/34.
Pełny tekst źródła
44
Fermor, Hazel Louise. "Engineering of natural cartilage substitution biomaterials." Thesis, University of Leeds, 2013. http://etheses.whiterose.ac.uk/6328/.
Pełny tekst źródłaStreszczenie:
Cartilage lesions cause pain and a loss of joint motion, and if not repaired will further degenerate into an osteoarthritic state. Currently the only treatment options for end stage osteoarthritis are total joint replacements, which are not preferable for younger or more active patients. Early intervention therapies to repair initial cartilage damage and stem the progression of osteoarthritis are thought to be a more favourable treatment option in appropriate cases. It is hypothesised that an acellular xenogeneic osteochondral scaffold could be used in mosaicplasty-like operations to provide an immunocompatible, off-the-shelf biomaterial for osteochondral lesion repair, retaining the same natural composition, structure and function as native cartilage. Initial characterisation of cartilages from different species (pig, cow and sheep) and joint regions of the hip and knee revealed differences in cartilage biology, biochemistry and biomechanics. Osteochondral tissues from skeletally immature porcine medial condyles were selected along with mature bovine femoral groove tissues as source materials for decellularisation, primarily based on cartilage thickness and glycosaminoglycan (GAG) content. Bovine osteochondral pins were subject to a number of decellularisation protocols and were shown to be successfully decellularised following use of a water pik to remove bone marrow, four cycles of freeze-thaw (two of which were in a hypotonic buffer with protease inhibitors), two cycles of hypotonic buffer followed by incubation in 0.1 % (w/v) SDS with protease inhibitors and treatment with nucleases and sterilisation with 0.1 % (v/v) peracetic acid. The process removed all whole cell nuclei, as visualised by histology and reduced cartilage DNA content per cartilage dry weight to 39 ng.mg-1. However, the process removed 99% of GAGs and resulted in reduced biomechanical properties. Porcine osteochondral pins were fully decellularised following use of the above process with one cycle of incubation in hypotonic buffer and 0.1 % (w/v) SDS in hypotonic buffer. Cartilage DNA content was reduced by 98% and the osteochondral tissues contained no visible cell nuclei. Cartilage GAG content was reduced by 60 %. Further alterations to the protocol to improve GAG retention revealed cartilage damage; histologically appearing highly porous and having greatly increased water content and almost complete GAG loss. A comprehensive investigation was conducted to identify the cause of the damage, however no protocol could be developed which completely eradicated cartilage damage. Further characterisation of acellular bovine osteochondral scaffolds showed that a low concentration of SDS remained in the bone, and that this had cytotoxic effects when incubated in contact with BHK cells. Further washes in PBS were added to the protocol to remove excess SDS, however this increased washing led to damage of the bovine cartilage, as seen previously in porcine osteochondral decellularisation. Finally, the decellularisation process was applied to whole porcine condyles in which the ratio of cut edge to cartilage area was minimised and minimal damage to the decellularised cartilage was seen. In summary, the complex microstructure of cartilage has been shown to be surprisingly fragile ex vivo and a novel approach to the development of clinically relevant acellular osteochondral grafts is required; however significant advances have been made in the current study.
45
Cruz, Daniel Alejandro. "Hierarchical Self-Assembly and Substitution Rules." Scholar Commons, 2019. https://scholarcommons.usf.edu/etd/7770.
Pełny tekst źródłaStreszczenie:
A set of elementary building blocks undergoes self-assembly if local interactions govern how this set forms intricate structures. Self-assembly has been widely observed in nature, ranging from the field of crystallography to the study of viruses and multicellular organisms. A natural question is whether a model of self-assembly can capture the hierarchical growth seen in nature or in other fields of mathematics. In this work, we consider hierarchical growth in substitution rules; informally, a substitution rule describes the iterated process by which the polygons of a given set are individually enlarged and dissected. We develop the Polygonal Two-Handed Assembly Model (p-2HAM) where building blocks, or tiles, are polygons and growth occurs when tiles bind to one another via matching, complementary bonds on adjacent sides; the resulting assemblies can then be used to construct new, larger structures. The p-2HAM is based on a handful of well-studied models, notably the Two-Handed Assembly Model and the polygonal free-body Tile Assembly Model.
The primary focus of our work is to provide conditions which are either necessary or sufficient for the ``bordered simulation'' substitution rules. By this, we mean that a border made up of tiles is allowed to form around an assembly which then coordinates how the assembly interacts with other assemblies. In our main result, we provide a construction which gives a sufficient condition for bordered simulation. This condition is presented in graph theoretic terms and considers the adjacency of the polygons in the tilings associated to a given substitution rule. Alongside our results, we consider a collection of over one hundred substitution rules from various sources. We show that only the substitution rules in this collection which satisfy our sufficient condition admit bordered simulation. We conclude by considering open questions related to simulating substitution rules and to hierarchical growth in general.
46
Droz, Johan. "La substitution dans le contrat de mandat /." Genève : Schulthess, 2008. http://aleph.unisg.ch/hsgscan/hm00243562.pdf.
Pełny tekst źródła
47
Zeitler, Berndt. "A comparative study of source substitution methods." [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=974828165.
Pełny tekst źródła
48
Frondel, Manuel. "Empirical and theoretical contributions to substitution issues." [S.l.] : [s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=962716057.
Pełny tekst źródła
49
Xie, Jianing. "Advancing Pd-catalyzed Stereoselective Allylic Substitution Reactions." Doctoral thesis, Universitat Rovira i Virgili, 2020. http://hdl.handle.net/10803/670221.
Pełny tekst źródłaStreszczenie:
Aquesta tesi doctoral se centra principalment en el desenvolupament de nous mètodes catalítics (dòmino) basats en la substitució al·lílica catalitzada per Pd per a la síntesi estereoselectiva de petites molècules funcionals i heterocicles utilitzant un disseny detallat de lligants i substrats. Aquesta tesi està organitzada en cinc capítols: el primer capítol és una introducció general sobre els aspectes bàsics de la química al·lílica. El segon capítol il·lustra el primer mètode general per a la preparació d'èters arílics al·lílics terciaris enantioenriquits mitjançant una eterificación regio- i enantio-selectiva catalitzada per Pd dels VCCs en presència de nucleòfils fenòlics. La regioselectivitat de la reacció pot ajustar-se selectivament al producte lineal Z canviant el lligant fosforamidit a un lligant monofosfina, demostrant així el paper crucial del disseny adequat del lligant. El tercer capítol descriu el disseny d'un nou alcohol al·lílic terciari equipat amb un grup carboxil, que s'utilitza en primer lloc per a la síntesi de γ-lactames α,β-insaturades mitjançant una aminació al·lílica estereoselectiva catalitzada per Pd, seguit d’un procés de ciclació intramolecular. Els estudis mecanístics suggereixen que el grup carboxil és crucial per a aquesta transformació i actua com un grup funcional activador i estereodirector. El quart capítol presenta un enfocament estereodivergent controlat pel lligant per a la síntesi de γ-aminoàcids amb configuració Z o E derivats d'alcohols al·lílics terciaris i amines secundàries. Els resultats experimentals destaquen el paper crucial del lligant de suport i l'angle de mossegada de la difosfina. El cinquè capítol informa sobre un mètode general per a la síntesi de caprolactames insaturades substituïdes a través d'un procés d'aminació / ciclació en cascada utilitzant vinil γ-lactones com a substrats mitjançant l'ús d'un lligant fosforamidito recentment desenvolupat. Finalment, s'extreu una conclusió general per a cada capítol i també es discuteix l’aplicació potencial d'aquestes metodologies desenvolupades.<br>Esta tesis doctoral se centra principalmente en el desarrollo de nuevos métodos catalíticos (dominó) basados en la sustitución alílica catalizada por Pd para la síntesis estereoselectiva de pequeñas moléculas funcionales y heterociclos utilizando un diseño detallado de ligandos y sustratos. Esta tesis está organizada en cinco capítulos: el primer capítulo es una introducción general sobre los aspectos básicos de la química alílica. El segundo capítulo ilustra el primer método general para la preparación de éteres arílicos alílicos terciarios enantioenriquecidos mediante una eterificación regio- y enantio-selectiva catalizada por Pd de los VCCs en presencia de nucleófilos fenólicos. La regioselectividad de la reacción puede ajustarse selectivamente al producto lineal Z cambiando el ligando fosforamidito a un ligando monofosfina, demostrando así el papel crucial del diseño adecuado del ligando. El tercer capítulo describe el diseño de un nuevo alcohol alílico terciario equipado con un grupo carboxilo, que se utiliza en primer lugar para la síntesis de γ-lactamas α,β-insaturadas mediante una aminación alílica estereoselectiva catalizada por Pd, seguido por un proceso de ciclación intramolecular. Los estudios mecanisticos sugieren que el grupo carboxilo es crucial para esta transformación y actúa como un grupo funcional activador y estereodirector. El cuarto capítulo presenta un enfoque estereodivergente controlado por el ligando para la síntesis de γ-aminoácidos con configuración Z o E derivados de alcoholes alílicos terciarios y aminas secundarias. Los resultados experimentales destacan el papel crucial del ligando de soporte y el ángulo de mordedura de la difosfina. El quinto capítulo informa sobre un método general para la síntesis de caprolactamas insaturadas sustituidas a través de un proceso de aminación / ciclación en cascada utilizando vinil γ-lactonas como sustratos mediante el uso de un ligando fosforamidito recientemente desarrollado. Finalmente, se extrae una conclusión general para cada capítulo y también se discute la aplicación potencial de estas metodologías desarrolladas.<br>This doctoral thesis is mainly focused on the development of novel catalytic (domino) synthesis methods based on Pd-catalyzed allylic substitution for the stereoselective synthesis of functional small molecules and heterocycles utilizing a detailed ligand engineering and substrate design. The scope of this thesis is organized into five chapters: the first chapter is a general introduction on the regular aspects of allylic chemistry. The second chapter illustrates the first general method for the preparation of enantioenriched tertiary allylic aryl ethers through a Pd-catalyzed regio- and enantio-selective etherification of VCCs in the presence of phenolic nucleophiles. The regioselectivity of the reaction can be finely tuned to the Z-selective linear product by switching the phosphoramidite ligand to a monophosphine ligand, thus proving the crucial role of proper ligand engineering. The third chapter describes a newly designed tertiary allylic alcohol equipped with a carboxyl group, which is firstly used for α,β-unsaturated γ-lactams synthesis through Pd-catalyzed stereoselective allylic amination and intramolecular cyclization process. Mechanistic studies suggest that the carboxyl group is crucial for this transformation, and acts as an activating and stereodirecting functional group. The fourth chapter presents a ligand-controlled stereodivergent approach for the synthesis of either Z or E-configured γ-amino acids derived from tertiary allylic alcohols and secondary amines. The experimental results highlight the crucial role of the supporting ligand and the diphosphine bite angle. The fifth chapter reports a general method for substituted unsaturated caprolactam synthesis through a cascade amination/cyclization process using vinyl γ-lactones as substrate by using a newly developed phosphoramidite ligand. Finally, a general conclusion for each chapter is given and potential applications for these developed methodologies are also discussed.
50
Baskurt, Ozge. "Financial Dollarization And Currency Substitution In Turkey." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606172/index.pdf.
Pełny tekst źródłaStreszczenie:
This study aims to investigate currency substitution and financial dollarization in Turkey. The extend of dollarization in Turkey appears to be very high according to both the conventional currency substitution and the recently developed financial dollarization measures. This has serious policy implications as a source of financial fragility through currency/maturity mismatches and balance sheet effects. The empirical part of this study contained an investigation of the long run relationships between the variables in a system containing currency substitution ratio, expected exchange rate change and rates of return on domestic and foreign currency denominated assets. The results of the Johansen cointegration analysis based on quarterly data for the 1987-2004 period appeared not to be strongly supporting the General Portfolio Balance Model (GPBM). The theoretical part of this study suggests that the GPBM can be reduced to the Sequential Portfolio Balance Model (SPBM) under the uncovered interest parity (UIP) hypothesis. Consequently, the GPBM may be misleading under UIP. The Johansen cointegration results suggested the validity of the UIP for the Turkish data. The estimation of the SPBM suggested that there is a long-run relationship between currency substitution and expected exchange rate change in Turkey. The elasticity of currency substitution appeared to be high but consistent with those estimated for other high inflation developing countries. The results further supported the presence of a ratchet/hysteresis effect proxied by a trend variable. All these results are consistent with the argument that currency substitution and financial dollarization are important especially in high inflation countries.