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Dissertations / Theses on the topic 'Polya groups'
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1
Bovo, Eduardo. "O teorema de enumeração de Polya, generalizações e aplicações." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/307501.
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Orientador: Jose Plinio de Oliveira SantosDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação Cientifica
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Resumo: Neste trabalho são desenvolvidos conceitos algébricos, analíticos e combinatórios que culminam no Teorema de Enumeração de Pólya; bem como são fornecidas muitas de suas aplicações em enumeração de padrões (grafos, colorações geométricas, tipos e permutações, etc). Tal teorema clássico, que tem suas bases em Teoria dos Grupos, utiliza fundamentalmente o conceito de funções geradoras, o que permite grande generalidade e computabilidade de resultados. Finalmente são apresentadas algumas generalizações do resultado principal, aplicações destas e também uma importante interpretação probabilística
Abstract: In this dissertation we present algebraic, analytic and combinatorial results that are used to prove Polya's Enumeration Theorem. Applications to counting patterns (graphs, colourings, permutations, etc.) are given. This classical Theorem has its foundations on the theory of groups and uses, mainly, the concept of generating functions which allows great generality and computability of results. At the end some generalizations of the main theorem are given including applications and, aiso, an important probabilistic interpretation
Mestrado
Combinatoria Enumerativa
Mestre em Matemática Aplicada
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Emmelin, Etienne. "Grοupes de classes et de Ροlya d'extensiοns abéliennes." Electronic Thesis or Diss., Normandie, 2024. http://www.theses.fr/2024NORMC241.
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Pour des extensions galoisiennes K/Q, le groupe de Pólya de K est un sous-groupedu groupe de classes d’idéaux de K engendré par les idéaux ambiges. On démontredans cette thèse l’existence d’une infinité d’extensions abéliennes K/Q, dont le groupede Pólya est isomorphe à un groupe abélien fini G, prescrit. Pour cela on se ramèneau cas des l-extensions cycliques et l’on utilise le théorème de structure des groupesabéliens finis. De plus, on étudie le comportement asymptotique du groupe de classesrelatif d’extensions CM abéliennes K/Q, défini comme étant le quotient du groupede classes Cl(K), par le groupe de Pólya Po(K) et l’on montre qu’il n’existe qu’unnombre fini de tels corps dont le groupe de classes relatif est trivial. Enfin, on démontrel’existence d’une infinité de corps quadratiques successifs en caractéristique strictementpositive, dont le nombre de classes est divisible par un nombre premier, en montrantun analogue du théorème de Siegel pour les corps de fonctionsFor Galois extensions K/Q, the Pólya group of K is a subgroup of the ideal classgroup of K generated by ambigous ideals. In this thesis, we prove the existence of infinitlymany abelian extensions K/Q, such that the Pólya group of K is isomorphic to aprescribed finite abelian group G. For this, we study the case of cyclic l-extensions andwe show the existence using the theorem of finite abelian group structure. In addition,we study the asymptotic behavior of the relative class group of abelian CM extensionsK/Q, defined as the quotient of the class group Cl(K) by the Pólya group Po(K) andwe show that there exists a finite number of such fields whose relative class group istrivial. Finally, we prove the existence of infinitely many successive quadratic field inpositive caracteristic, whose class number is divisible by a prime number, by showingan analogous of Siegel’s theorem for function fields
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Brough, Tara Rose. "Groups with poly-context-free word problem." Thesis, University of Warwick, 2010. http://wrap.warwick.ac.uk/35716/.
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We call a language poly-context-free if it is an intersection of finitely many contextfree languages. In this thesis, we consider the class of groups with poly-context-free word problem. This is a generalisation of the groups with context-free word problem, which have been shown by Muller and Schupp [17, 3] to be precisely the finitely generated virtually free groups. We show that any group which is virtually a finitely generated subgroup of a direct product of finitely many free groups has poly-context-free word problem, and conjecture that the converse also holds. We prove our conjecture for several classes of soluble groups, including the metabelian groups and torsion-free soluble groups, and present progress towards resolving the conjecture for soluble groups in general. Some results in the thesis may be of independent interest in formal language theory or group theory. In Chapter 2 we develop some tools for proving a language not to be poly-context-free, and in Chapter 5 we prove that every finitely generated soluble group which is not virtually abelian has a subgroup of one of a small number of types.
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MORESCHINI, LORENZO. "Poly-free constructions for some Artin groups." Doctoral thesis, Università degli studi di Pavia, 2019. http://hdl.handle.net/11571/1292066.
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Artin-Tits groups have fruitfully been studied since the thirties when Emil Artin introduced the family of braid groups in the context of knot theory.
The precise definition of the whole family of Artin-Tits groups is due to Jacques Tits in the seventies who introduced them as extensions of Coxeter groups.
Although their definition is purely algebraic and relies on certain combinatorial data encoded in a so called "Coxeter graph", their study is not limited to their own field, but connections with other branch of mathematics has been discovered such as geometric group theory and algebraic topology.
Since the definition of Artin-Tits groups is given by means of Coxeter graphs, it's quite natural to wonder whether there exists any connection between the structure of the combinatorial data that is written in the graph and the algebraic properties of the associated group.
Not surprisingly, this is sometimes the case and a number of results we present in this thesis state hypotheses on the structure of the Coxeter graph in order to infer algebraic information regarding the Artin-Tits group associated to it.
However, the "slightest variation" in the structure of the graph may change a lot the properties of the related Artin-Tits group.
This situation has the consequence that many general questions about these groups have been answered only for some more or less extended families using tools specifically developed for that cases.
E.g., we do not know if all Artin-Tits groups are torsion free and proofs are known only for some of them.
In particular, in our thesis we want to study poly-freeness, a strong structural property of groups that in turn implies an affirmative answer to questions like torsion-freeness, orderability and others.
We achieve that the only poly-free Artin-Tits groups of finite type are those of type I_2(n) (n >= 3), A_3, B_3, B_4 and D_4 (with the only possible exception of F_4 which remains unknown at the moment). Moreover, we prove that all Artin-Tits groups whose associated graph is a tree or a forest are poly-free and in the last part we give an affirmative result about poly-freeness of Artin-Tits groups built starting from graphs that may be "more connected" than just a tree or a forest and that we hope to be able to further generalise in the future.Artin-Tits groups have fruitfully been studied since the thirties when Emil Artin introduced the family of braid groups in the context of knot theory. The precise definition of the whole family of Artin-Tits groups is due to Jacques Tits in the seventies who introduced them as extensions of Coxeter groups. Although their definition is purely algebraic and relies on certain combinatorial data encoded in a so called "Coxeter graph", their study is not limited to their own field, but connections with other branch of mathematics has been discovered such as geometric group theory and algebraic topology. Since the definition of Artin-Tits groups is given by means of Coxeter graphs, it's quite natural to wonder whether there exists any connection between the structure of the combinatorial data that is written in the graph and the algebraic properties of the associated group. Not surprisingly, this is sometimes the case and a number of results we present in this thesis state hypotheses on the structure of the Coxeter graph in order to infer algebraic information regarding the Artin-Tits group associated to it. However, the "slightest variation" in the structure of the graph may change a lot the properties of the related Artin-Tits group. This situation has the consequence that many general questions about these groups have been answered only for some more or less extended families using tools specifically developed for that cases. E.g., we do not know if all Artin-Tits groups are torsion free and proofs are known only for some of them. In particular, in our thesis we want to study poly-freeness, a strong structural property of groups that in turn implies an affirmative answer to questions like torsion-freeness, orderability and others. We achieve that the only poly-free Artin-Tits groups of finite type are those of type I_2(n) (n >= 3), A_3, B_3, B_4 and D_4 (with the only possible exception of F_4 which remains unknown at the moment). Moreover, we prove that all Artin-Tits groups whose associated graph is a tree or a forest are poly-free and in the last part we give an affirmative result about poly-freeness of Artin-Tits groups built starting from graphs that may be "more connected" than just a tree or a forest and that we hope to be able to further generalise in the future.
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Leriche, Amandine. "Groupes, corps et extensions de Polya : une question de capitulation." Phd thesis, Université de Picardie Jules Verne, 2010. http://tel.archives-ouvertes.fr/tel-00612597.
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Dans cette thèse, nous nous intéressons à l'ensemble $Int\left(\mathcal O _K \right)$ des polynômes à valeurs entières sur l'anneau $\mathcal{O}_K$ des entiers d'un corps de nombres $K$. Selon Pólya, une base $\left(f_{n}\right)_{n\in \mathbb{N}}$ du $\mathcal O _K$-module $Int\left(\mathcal O _K \right)$ est dite régulière si pour tout $n \in \mathbb{N}$, $\deg(f_{n})=n$. Un corps $K$ tel que $ Int \left(\mathcal{O}_K \right)$ possède une base régulière est dit de Pólya et le groupe de Pólya d'un corps de nombres $K$ est un sous-groupe du groupe de classes de $K$ qui peut être considéré comme une mesure de l'écart pour un corps au fait d'être de Pólya. Nous étudions le groupe de Pólya d'un compositum $L= K_1 K_2$ de corps de nombres galoisiens et établissons des liens avec la ramification des nombres premiers dans chacune des extensions $K_1 /\mathbb{Q}$ et $K_2 /\mathbb{Q}$. Nous appliquons ces résultats aux corps de nombres de petit degré afin d'élargir la famille des corps de Pólya quadratiques déjà caractérisés. Par ailleurs, une condition pour qu'un corps de nombres $K$ soit de Pólya est que tous les produits d'idéaux de $K$ de même norme soient principaux. Par analogie avec le problème classique du plongement, on peut se poser la question suivante : tout corps de nombres $K$ peut-il être plongé dans un corps de Pólya? Nous donnons une réponse positive à cette question : pour tout corps $K$, le corps de classes de Hilbert $H_K$ de $K$ est un corps de Pólya . Toujours par analogie avec le problème de plongement où l'on sait que les idéaux de $\mathcal{O}_K$ deviennent principaux dans $\mathcal{O}_{H_K}$, on peut définir la notion d'extension de Pólya d'un corps $K$ : il s'agit de corps $L$ contenant $K$ dans lesquels le groupe de Pólya de $K$ devient trivial par extensions des idéaux, ce sont aussi des corps $L$ tels que le $\mathcal O _L$-module engendré par $Int\left(\mathcal O _K \right)$ possède une base régulière. Outre $H_K$ dans le cas général, dans le cas où $K$ est une extension abélienne, la capitulation des idéaux ambiges de $K$ montre que le corps de genre de $K$ en est une extension de Pólya. Ceci nous amène à des questions de minimalité et d'unicité concernant les corps et extensions de Pólya.
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Cameron, Donald King. "Some reactions of unsaturated ring systems containing sulphonyl groups." Thesis, University of Edinburgh, 1987. http://hdl.handle.net/1842/10859.
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Green, Shawn Jeffrey. "Extensions of the Power Group Enumeration Theorem." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/7526.
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The goal of this paper is to develop extensions of Polya enumeration methods which count orbits of functions. De Bruijn, Harary, and Palmer all worked on this problem and created generalizations which involve permuting the codomain and domain of functions simultaneously. We cover their results and specifically extend them to the case where the group of permutations need not be a direct product of groups. In this situation, we develop a way of breaking the orbits into subclasses based on a characteristic of the functions involved. Additionally, we develop a formula for the number of orbits made up of bijective functions. As a final extension, we also expand the set we are acting on to be the set of all relations between finite sets. Then we show how to count the orbits of relations.
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Abdellatif, Mohamed Moustafa. "Poly(arylene ether)s with Truly Pendant Benzene Sulfonic Acid Groups." Wright State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=wright1222544981.
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de, Santiago Rolando. "Structural results for von Neumann algebras of poly-hyperbolic groups." Diss., University of Iowa, 2017. https://ir.uiowa.edu/etd/5745.
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This work is a compilation of structural results for the von Neumann algebras of poly-hyperbolic groups established in a series of works done jointly with I. Chifan and T. Sinclair; and S. Pant. These works provide a wide range of circumstances where the product structure, a discrete structural property, can be recovered from the von Neumann algebra (a continuous object).
The primary result of Chifan, Sinclair and myself is as follows: if Γ = Γ1 × · · · × Γn is a product of non-elementary hyperbolic icc groups and Λ is a group such that L(Γ)=L(Λ), then Λ decomposes as an n-fold product of infinite groups. This provides a group-level strengthening of the unique prime decomposition of Ozawa and Popa by eliminating any assumption on the target group Λ. The methods necessary to establish this result provide a malleable procedure which allows one to rebuild the product of a group from the algebra itself.
Modifying the techniques found in the previous work, Pant and I are able to demonstrate that the class of poly-groups exhibit a similar phenomenon. Specifically, if Γ is a poly-hyperbolic group whose corresponding algebra is non-prime, then the group must necessarily decompose as a product of infinite groups.
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Formosa, Joseph S. "Thermal degradation of polymer blends containing the poly (hydroxy, ether of bisphenol-A) /." Online version of thesis, 1987. http://hdl.handle.net/1850/10289.
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Franklin, Jeff E. "Implantation of Biocompatible Fibers for the Coupling of Muscle Groups." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1123702272.
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Franckevičius, Marius. "Excited-state dynamics of PPI and PAMAM dendrimers functionalized with photochromic terminal groups." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20111003_114600-62082.
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Dendrimers are multivalent, well-defined materials that constitute a new class of polymer macromolecules. They have been extensively studied over the past several decades mainly due to their exceptional structure properties. The size of molecule, number of terminal groups, molecular weight and several other properties of dendrimers could be precisely controlled during synthesis.
The main goal of this thesis is to investigate the optical properties and light induced photochemical reaction dynamics within the PPI and PAMAM dendrimers functionalized by CAzPA and ESA type terminal groups by means of several spectroscopic techniques. Because photochromism of CAzPA and ESA type terminal groups is associated with light induced isomerization and tautomerization photochemical reactions, the main attention of present thesis was devoted to investigate dynamical properties of functionalized dendrimers as an influence of dendrimer type and its generation.
Investigations of dynamic properties of PPI and PAMAM dendrimers functionalized with the CAzPA terminal groups have shown that isomerization rate is insensitive to dendrimer type, solvent and excitation wavelength. The isomerization rate of the dendrimer films take place in about 15 ps and it is only seven times slower than in dendrimer solvent.
Both experimental and theoretical optical studies performed on PPI dendrimers functionalized with the ESA type terminal groups reveal four stable tautomeric forms with different energy in the... [to full text]Dendrimerai tai naujai dendritinių polimerų klasei priskiriamos makromolekulės. Jų dydis, funkcinių grupių skaičius yra tiksliai apibrėžti ir gali būti kontroliuojami sintezės metu. Dėl išskirtinių struktūrinių savybių, dendrimerai jau keletą dešimtmečių yra intensyviai tiriamos medžiagos. Pagrindinis disertacijos tikslas yra ištirti PPI ir PAMAM dendrimerų, funkcionalizuotų CAzPA ir ESA fotochrominiais junginiais optines savybes bei šviesa inicijuotų fotocheminių reakcijų dinamiką panaudojus kelias tyrimų metodikas. Kadangi CAzPA ir ESA junginių fotochromizmas yra susijęs su šviesa indukuota izomerizacijos bei tautomerizacijos fotocheminėmis reakcijomis, todėl darbe buvo siekiama ištirti šiais junginiais funkcionalizuotų dendrimerų dinaminių savybių priklausomybę nuo dendrimero tipo bei jo generacijos. Ištyrus PPI ir PAMAM dendrimerų funkcionalizuotų CAzPA junginiais plėvelių ir tirpalų dinamines savybes, buvo nustatyta, kad izomerizacijos sparta nepriklauso nuo dendrimero tipo, tirpiklio ir žadinančios spinduliuotės energijos. Dendrimerų plėvelių sužadintos būsenos relaksacijos trukmė yra apie 15 ps, o tai apie 7 kartus lėčiau nei tirpaluose. Eksperimentiškai ir teoriškai ištyrus skirtingų generacijų PPI dendrimerų funkcionalizuotų ESA fotochrominiais junginiais optines savybes, buvo nustatytos keturios stabilios ESA funkcinių grupių tautomerinės formos, kurių pagrindinės būsenos energijos yra skirtingos. Skirtingų dendrimero generacijų sužadintos būsenos dinamikos... [toliau žr. visą tekstą]
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Plenderleith, Richard. "End group functionalised highly branched poly(N-isopropylacrylamides) in biomaterials." Thesis, University of Sheffield, 2015. http://etheses.whiterose.ac.uk/11861/.
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Hubbard, K. Lise. "The study of poly(Divinylbenzene-co-Ethylvinylbenzene) and modifications to the pendant vinylbenzene groups." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0013/NQ36984.pdf.
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Yeomans, Kevin A. "Novel poly(aryl ether)s containing nitrile groups : synthesis, characterization and cross-linking studies." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=67538.
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Four novel aromatic difluoride compounds were synthesized for use as monomers in nucleophilic aromatic displacement polymerization reactions. Attempts were then made to polymerize these monomers with a series of bisphenols, using potassium carbonate as a base, in a dipolar aprotic solvent as in equation 1. eqalign qquad{& rm K sb2CO sb3 cr rm F{-}Ar{-}F + HO{-}Ar{-}OH quad& rm quad longrightarrow quad quad bigl(O{-}AR{-}O{-}Ar bigr) sb{n} cr& rm Dipolar aprotic cr& rm solvent cr& rm 160-195 sp circ C cr} eqno(1) sing the reaction above, several novel poly(aryl ether)s have been produced and some of their physical properties, such as glass transition temperature and thermal stability, have been investigated. The polymers all contain nitrile groups which have potential to form cross-links upon heating, thereby increasing the use temperature and solvent resistance of the resulting materials. This cross-linking potential was investigated. Also, polymers containing the 9,10-dicyanophenanthrene moiety were prepared and then reacted with cuprous chloride and phthalonitrile to give poly(aryl ether)s containing copper phthalocyanine groups.
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Hubbard, K. Lise (Kirsten Lise-Lotte). "The study of poly(Divinylbenzene-co-ethylvinylbenzene) and modifications to the pendant vinylbenzene groups /." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34644.
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Cross-linked resins of poly(divinylbenzene-co-ethylvinylbenzene) were characterized and modified by a variety of reactions with the pendant vinylbenzene groups. Laboratory-prepared resins of a known composition were compared and contrasted to a commercial version with regard to surface area, porosity, and vinylbenzene content. The commercial resin, Amberlite XAD-4 (Rohm and Haas Company), had a higher surface area (831 m2 /g), porosity (1.18 mL/g), and accessible vinylbenzene groups (2.5 mmol/g, degree of functionalization 33%). Modifications of both resins by radical addition of a variety of thiols led to higher conversions (of vinylbenzene groups to modified groups) with use of the commercial resin (as high as 76%). Further modifications were done strictly with XAD-4. Some thiol additions to XAD-4 were done with water as the solvent, with conversions as high as 43%. Disulfides were added across the vinylbenzene groups of XAD-4 with iodine catalysis, with conversions as high as 55%. This simple one-step reaction has never been done with a polymer system before. XAD-4 was completely epoxidized using a solution of dimethyldioxirane in acetone, and completely brominated to form a resin with (1,2-dibromoethyl)benzene groups (3.76 mmol Br/g). Resins with (1-hydroxy-2-bromoethyl)benzene groups (1.5 mmol/g) were prepared by reaction of XAD-4 with N-bromosuccinimide and water, with 73% conversion. Resins with thiol groups (2.5 mmol S/g) were prepared by a one-pot reaction of brominated XAD-4 with N,N-dimethylthioformamide followed by methanolysis. From one commercially-available resin, several polymers with a variety of functional groups have thus been prepared by simple one- to three-step modifications.
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Atkinson, Deborah Jane. "Stress response and inorganic poly-phosphate in the Bacillus group bacteria." Thesis, University of Bath, 2010. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.538113.
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This thesis concentrates on the Bacillus cereus group of organisms and interactions that they may encounter in their natural environment. Inorganic polyphosphate has been identified as an important factor of stress and survival in B. cereus. One of the aims of this project was to create knock out mutants of certain enzymes involved in polyphosphate metabolism in B. anthracis, the etiological agent of anthrax. Unfortunately, even though B. anthracis is very closely related to B. cereus and despite the application of published methods it was not possible to create these B. anthracis knockout mutants. In order to address the importance of inorganic polyphosphate in B. anthracis, a real time RT‐PCR assay was developed to monitor the mRNA levels of these enzymes when the bacterium is faced with harsh nutrient environments Real time RT‐PCR analysis showed that mRNA levels of the metabolizing enzymes were upregulated in low nutrient conditions but that the profiles of gene expression were varied when grown in a chemically defined media. In addition to abiotic stresses such as low nutrients, B. anthracis is also likely to face biotic stress such as predation by amoeba in the soil. Investigations were performed into the outcome of the interaction of B. cereus group bacteria with a model amoeba, Acanthamoeba polyphaga. Amoebae are bacterial predators but can also be utilised as hosts by bacterial symbionts and pathogens, such as Legionella pneumophila. It was theorised that amoebae may provide a host environment similar to that of the professional macrophages, which B. anthracis encounters in mammalian infection. These investigations confirmed that the B. cereus group bacteria demonstrate a range of interactions with amoeba cells, from surface attachment through to intracellular persistence. These studies went on to show that B. cereus, B. thuringiensis and B. anthracis can all be engulfed by amoebae when challenged in their vegetative form and that spores were able to survive, and apparently germinate. Finally these studies have identified a new developmental stage of the B. cereus group bacteria. When grown in static conditions, especially in the presence of amoeba, the bacterial cells cease to septate and large (often motile) continuous hyphae like filaments form. These filaments can be seen to “weave” together to form large “rope” like macrofibre structures which can even become visible by eye. Previously this macrofibre growth has also been seen in B. subtilis, suggesting it may be common to the whole genus. In the light of these findings we speculate that this group of pathogens have evolved complex behaviours to interact with soil amoeba in order to facilitate survival in harsh environmental conditions.
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Rouzaud, Jacques. "Di- et poly-métallocènes du groupe 14 (Ge, Sn) à espaceurs conjugués." Toulouse 3, 2001. http://www.theses.fr/2001TOU30094.
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Kern, Kimberly E. "Poly(arylene ether sulfone)s Carrying Pendant(3-sulfonated) phenyl sulfonyl Groups for use as Proton Exchange Membranes." Wright State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=wright1308770965.
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Schumacher, Trevor I. "Poly(arylene ether sulfone)s with Ammonium Groups Located on PendentPhenyl Sulfonyl Moieties for Anionic Exchange Membranes." Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1468932871.
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Toda, Mitsuaki. "Complement activation on surfaces carrying hydroxyl or amino groups." 京都大学 (Kyoto University), 2010. http://hdl.handle.net/2433/120910.
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Despres, Typhaine. "Synthesis of hyperbranched polymers with multiple reactive terminal groups by RAFT-SCVP." Electronic Thesis or Diss., Le Mans, 2024. http://www.theses.fr/2024LEMA1022.
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Ce projet vise à élaborer des polymères hyper-ramifiés (HBP) cationiques porteurs de multiples groupements terminaux fonctionnels afin de développer le multi-ciblage cellulaire de nouveaux vecteurs de gènes thérapeutiques. Ces HBP sont prometteurs pour traiter les troubles vasculaires et prévenir les maladies cardio-vasculaires associées à un dysfonctionnement endothélial chez les patients diabétiques. Les HBP, présentant de grands volumes intérieurs et un nombre élevé de groupes terminaux en périphérie, sont le plus souvent limités à un seul type de groupement terminal. La stratégie choisie pour lever ce verrou scientifique repose sur la combinaison de la polymérisation par auto-condensation de monomères vinyliques (SCVP) et de la polymérisation par transfert de chaîne par addition-fragmentation réversible (RAFT) suivie de la chimie de l’azlactone pour ancrer une grande variété de fonctions réactives chimiosélectives à la périphérie des HBP. Cette stratégie a été appliquée à la synthèse d’HBP neutres cationisables et porteurs du groupement thiocarbonylthio par RAFT-SCVP du méthacrylate de 2-N,N-diméthylaminoéthyle (DMAEMA) et du 2-(méthacryloyloxy)éthyl 4-cyano-4-(((propylthio)carbonothioyl)thio) pentanoate (R-transmer). Plusieurs HBP ont été synthétisés en faisant varier le rapport molaire DMAEMA/R-transmer, produisant ainsi une gamme d’HBP possédant des masses molaires moyennes en nombre allant de 8 300 à 45 800 g.mol-1, des dispersités supérieures à 1,59 et des degrés de branchement variés compris entre 0,05 et 0,.30. Ces HBP ont ensuite été modifiés chimiquement par cationisation des unités DMAEMA afin de proposer des entités capables de complexer l’ARN interférent anti-PTP1B, protéine d’intérêt dans le traitement du dysfonctionnement endothélial. Les HBP neutres ont également été fonctionnalisés par un dérivé de poly(éthylène glycol) et la modification des motifs terminaux thiocarbonylthio a permis d’ancrer successivement différents groupements réactifs via une séquence d’aminolyse, de thiol-ène et de réaction d’aminolyse azlactone-amine de type click, pour obtenir en périphérie des fonctions amines réactives pour la conjugaison avec des peptides de ciblage. Ainsi, des HBP originaux, neutres, PEGylés ou non, fonctionnalisés par des amines ont été obtenus. Ces composés finaux, ainsi que certains intermédiaires de synthèse, seront soumis à des tests biologiques réalisés en collaboration avec le laboratoire MINT à Angers afin d’évaluer leur cytotoxicité, leur capacité à complexer l’ARN et leur efficacité de transfection, in vitro et in vivoThis project aims at the synthesis of cationic hyperbranched polymers (HBP) with multiple functional end-groups to enable multi-targeting of cells with novel therapeutic gene vectors. These HBP hold potential for treating diabetes-associated vascular disorders and preventing cardiovascular diseases associated with endothelium dysfunction. HBP, characterized by their large interior volumes and a high number of terminal end-groups in periphery, are limited to a single type of terminal group. To overcome this limitation, the proposed strategy is based on the combination of self-condensing vinyl polymerization (SCVP) and reversible addition-fragmentation chain transfer (RAFT) polymerization, followed by the azlactone chemistry to anchor a high diversity of chemoselective reactive functions on the HBP periphery. This approach was applied to the synthesis of neutral, cationizable HBP with thiocarbonylthio groups using RAFT-SCVP of 2-N,N-dimethylaminoethyl methacrylate (DMAEMA) and 2-(methacryloyloxy)ethyl 4-cyano-4-(((propylthio)carbonothioyl)thio)pentanoate (R-transmer). By varying the DMAEMA/R-transmer molar ratio, a range of HBP with number-average molecular weight from 8 300 to 45 800 g.mol-1, dispersity above 1.59, and degree of branching between 0.05 and 0.30 has been synthesized. These HBP were further modified by cationization of the DMAEMA units to provide moieties able of electrostatic complexation with siRNA anti-PTP1B, a protein implicated in the endothelial dysfunction. The neutral HBP were also functionalized with a derivative of poly(ethylene glycol) and the thiocarbonylthio terminal groups were modified to anchor various reactive groups through a sequence of aminolysis, thiol-ene and azlactone-amine click reaction, in order to target reactive amines functions at the periphery able to conjugate with targeting peptides. Thus, new neutral, PEGylated and non-PEGylated, HBP displaying reactive amines functions were prepared. These final compounds, as well as some synthesis intermediates, will be submit to in vitro and in vivo biological tests in collaboration with the MINT laboratory in Angers, in order to evaluate their cytotoxicity, siRNA complexation and transfection efficiencies
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Tobiesen, Finn Andrew. "A method for grafting poly(acrylic acid) onto nylon 6,6 using amine end-groups on the nylon surface." Thesis, Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/29994.
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Ekanayake, Herath Mudiyanselage Sujeewani K. "Poly(Organophosphazenes) with Azolylmethylphenoxy and Pyridinoxy Side Groups to be used as Proton Exchange Membranes in Fuel Cells." University of Akron / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=akron1321289351.
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Kim, Yoon-Sung. "Synthèse, caractérisation et structure de poly bêta-amides portant des groupes latéraux dérivés du carbazole." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb37614748g.
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KAYSER, DOMINIQUE. "Syntheses radicalaires de copolymeres sequences poly(dimethylsiloxane) poly(vinyliques) par la technique des iniferters. Preparation de nouveaux groupes fonctionnels actifs. Etudes cinetiques et caracterisations." Université Louis Pasteur (Strasbourg) (1971-2008), 1992. http://www.theses.fr/1992STR13184.
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Le travail realise s'inscrit dans le cadre de la mise au point de nouveaux procedes de polymerisation de monomeres vinyliques, bases sur l'utilisation de la technique des iniferters, en vue de synthetiser des copolymeres sequences poly(dimethylsiloxane)-poly(vinyliques) par voie radicalaire. Cette technique developpee recemment au laboratoire repose sur les proprietes thermiques des disulfures de thiurame, et sur la synthese de nouveaux groupements fonctionnels de type disulfures de bis-carbamyle. Elle consiste a introduire un ou plusieurs de ces groupements dans une macromolecule de poly(dimethylsiloxane) pour obtenir les macro et polyiniferters qui sont les precurseurs des copolymeres trisequences pdms-b-poly(vinyliques-b-pdms et multisequences pdms-b-poly(vinyliques)#n. Un interet particulier a ete porte a l'etude cinetique de la polymerisation du styrene et du methacrylate de methyle, en masse et en solution dans le toluene, amorcee par des macro et polyiniferters appartenant aux deux familles. Les principaux parametres cinetiques qui regissent ces polymerisations sont determines par exploitation mathematique des resultats experimentaux. La connaissance de ces grandeurs permet d'optimiser le procede de polymerisation et de synthetiser des copolymeres a teneur elevee en poly(dimethylsiloxane). La caracterisation morphologique de ces materiaux par diverses techniques physicochimiques met en evidence une heterogeneite de structure resultant de l'incompatibilite des sequences siloxane et methacrylate de methyle. Par ailleurs, ces composes presentent une excellente stabilite thermique ainsi qu'une bonne tenue au rayonnement uv
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Bouyahyi, Miloud. "Nouveaux complexes organométalliques à base de métaux des groupes 3 et 13 pour la polymérisation d'esters cycliques." Rennes 1, 2009. http://www.theses.fr/2009REN1S080.
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Les polyesters aliphatiques constituent une alternative très prometteuse en vue de remplacer les plastiques conventionnels par des matériaux capables de se dégrader après leur utilisation. Ces polymères appartiennent à la famille des polymères « biodégradables » et même bioassimilables car les produits de leur dégradation sont compatibles et métabolisés par les microorganismes. L'étude présentée dans ce manuscrit consistait en la synthèse de nouveaux complexes organométalliques à base de métaux oxophiles (aluminium et yttrium) pour la polymérisation stéréosélective d'esters cycliques. Le compte rendu de ces recherches est présenté dans ce manuscrit de la façon suivante : Le premier chapitre est consacré aux rappels bibliographiques afférents à notre étude. L'intérêt est accordé dans un premier temps aux différents polyesters qui ont fait l'objet de ce travail (PLA, PCL et PHB) et, dans un second temps, nous décrivons les systèmes catalytiques à base de métaux les plus connus pour la polymérisation d'esters cycliques. En ce qui concerne les initiateurs à base de l'aluminium, nous avons décrit dans le deuxième et le troisième chapitre l'étude détaillée de la synthèse et la caractérisation de nouveaux complexes d'aluminium à base de ligands (di)imino-(di)alcoolates fluorés et de ligands acétylacétonates fluorés. Le quatrième chapitre était dévolu entièrement à la synthèse des nouveaux initiateurs à base d'yttrium pour la polymérisation stéréosélective d'esters cycliques. L'objectif principal de ce dernier chapitre a été atteint en synthétisant des complexes qui présentent un excellent degré de contrôle stéréochimique pour la polymérisation du lactide et de la butyrolactone racémique. Enfin, Le cinquième chapitre rassemble quant à lui tous les modes opératoires expérimentaux qui se rapportent à cette étudeAmong various families of biodegradable polymers, aliphatic polyesters have a leading position since hydrolytic and/or enzymatic chain cleavage yields hydroxy-carboxylic acids, which in most cases are ultimately metabolized. Aliphatic polyesters are receiving increasing attention for their use in a wide variety of surgical and pharmaceutical applications as well as in disposable packaging. Typical examples of synthetic, biodegradable polymers are polylactide (PLA), polyhydroxybutyrate (PHB) and poly('-caprolactone) (PCL). Although these polyesters can be prepared by different approaches, the most convenient and efficient method to obtain well suited polyesters is the ring-opening polymerization (ROP) of the corresponding lactones. These researches aim to investigate new single site group 3 and 13 metal complexes for the ring-opening polymerization of rac-lactide (rac-LA), '-caprolactone and rac-'-butyrolactone (rac-BBL). Some of these original complexes have shown high activity and productivity for the controlled isotactic or heterotactic living polymerization of rac-LA and for the syndiotactic living polymerization of rac-BBL. The synthesis, structural features and catalytic performances of these complexes (amino-alkoxy-bis(phenolate) yttrium and aluminum complexes of fluorinated dialkoxy-diimino salen-like ligands) is detailed
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Kim, Yoon-Sung. "Synthese, caracterisation et structure de poly beta-amides aspartiques portant des groupes lateraux derives du carbazole." Paris 6, 1988. http://www.theses.fr/1988PA066331.
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Polymerisation non-assistee des esters benzylique, carbazolyl-9 ethyliques-2 et du (carbazolyl-9) ethylamide-2 de l'acide oxo-4 azetidinecarboxylique-2 et etude par ir de leur structure et notamment des liaisons imide inter- et intramoleculaire
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Cisáriková, Barbora. "Příprava a charakterizace biologicky rozložitelných kompozitů na bázi polyhydroxyalkanoátů a kávové sedliny." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2020. http://www.nusl.cz/ntk/nusl-433094.
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This diploma thesis was focused on the preparation and characterization of biodegradable composites based on poly-3-hydroxybutyrate (PHB) and spent coffee grounds (SCG). The aim was to prepare biocomposites based on PHB and coffee grounds. Biocomposites were prepared by solution casting in chloroform. Films with a thickness of about 150-200 µm were prepared with the addition of 20% unmodified and modified coffee grounds. The PHB/SCG films were modified by an addition of a plasticizer and a crosslinking agent or by blending with polybutylene adipate terephthalate (PBAT). The thermal properties of the films were determined by differential scanning calorimetry. The compatibility filler/polymer matrix compatibility was assessed morphologically with the naked eye. It has been found that the direct addition of spent coffee grounds to the PHB is not suitable due to the deterioration of the morphology of the film surfaces and the formation of aggregates. The compatibility between the spent coffee grounds and the PHB was improved after the addition of the plasticizer and the crosslinking agent. However, the highest compatibility between SCG and PHB was achieved in the case of esterified coffee grounds. Another way to improve the resulting morphological properties of the films thus prepared was to use coffee grounds fractions.
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Castiglione, Andrea. "Liquid crystalline macromolecular architectures based on regioregular poly(3-alkylthiophene) as backbone and calamitic mesogens as side-groups : towards ambipolar materials." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066693.
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Très récemment, le potentiel des semi-conducteur organiques (OSC) ambipolaires à attiré l'attention par de nombreuses applications technologiques. Dans le domaine de la microélectronique organique, l'un des obstacles majeurs pour le développent des OSC est le design de systèmes capables de transporter à la fois les électrons et les trous. Les matériaux semi-conducteurs ambipolaires ordonnés, peuvent répondre à cette problématique. Dans ce contexte nous avons développé la synthèse et la caractérisation d'une architecture macromoléculaire originale, fondée sur l'association d'un polymère semi-conducteur régiorégulier d'une part, avec des molécules ?-conjuguées cristal liquides ayant la propriété de s'auto-organiser spontanément d'autre part. Afin d'améliorer les propriétés mésomorphes et électroniques de ce système macromoléculaire, une gamme de composés différant par (i) la nature chimique du groupement pendant et (ii) le dégrée de polymérisation moyen du polymère à été synthétisée. La présence d'une mesophase a été confirmée pour chacun de ces composés par diffraction des rayons X et une mesophase de type lamello-lamellaire, présentant une alternance de couches électron-donneur ou électron-accepter à également pu être mis en évidenceVery recently ambipolar organic semi-conductors (OSC) have gaining attention for their potential use in numerous technologically relevant applications. Representative technological examples are the area of organic microelectronics where patterning of p- and n-channel semiconductors is one of the major hurdles for the implantation of OSC in organic complementary logic circuit. To achieve this objective, well-ordered ambipolar semiconducting materials are needed. In this work we investigated the self-organization and the electronic properties of a series of side chain liquid crystal (SCLC) semiconducting polymers where: (i) the backbone is a π-conjugated polymer and (ii) the side-groups are π-conjugated calamitic mesogens. We present our results on the design, synthesis, and structural characterization of this new liquid crystal regioregular poly(3-alkylthiophene) polymer family post-functionalized with side-on calamitic moieties. The parameters of these materials are: (i) the chemical nature of the side-group moieties and (ii) the degree of polymerization. As a result we will show that this strategy leads to the supramolecular self-assembly of this SCLC semiconducting polymer in a peculiar lamello-lamellar mesophase, where the two different lamellas present two different electronic properties, such as electron donor and electron acceptor behaviors
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Castiglione, Andrea. "Liquid crystalline macromolecular architectures based on regioregular poly(3-alkylthiophene) as backbone and calamitic mesogens as side-groups : towards ambipolar materials." Electronic Thesis or Diss., Paris 6, 2014. http://www.theses.fr/2014PA066693.
Full textAbstract:
Très récemment, le potentiel des semi-conducteur organiques (OSC) ambipolaires à attiré l'attention par de nombreuses applications technologiques. Dans le domaine de la microélectronique organique, l'un des obstacles majeurs pour le développent des OSC est le design de systèmes capables de transporter à la fois les électrons et les trous. Les matériaux semi-conducteurs ambipolaires ordonnés, peuvent répondre à cette problématique. Dans ce contexte nous avons développé la synthèse et la caractérisation d'une architecture macromoléculaire originale, fondée sur l'association d'un polymère semi-conducteur régiorégulier d'une part, avec des molécules ?-conjuguées cristal liquides ayant la propriété de s'auto-organiser spontanément d'autre part. Afin d'améliorer les propriétés mésomorphes et électroniques de ce système macromoléculaire, une gamme de composés différant par (i) la nature chimique du groupement pendant et (ii) le dégrée de polymérisation moyen du polymère à été synthétisée. La présence d'une mesophase a été confirmée pour chacun de ces composés par diffraction des rayons X et une mesophase de type lamello-lamellaire, présentant une alternance de couches électron-donneur ou électron-accepter à également pu être mis en évidenceVery recently ambipolar organic semi-conductors (OSC) have gaining attention for their potential use in numerous technologically relevant applications. Representative technological examples are the area of organic microelectronics where patterning of p- and n-channel semiconductors is one of the major hurdles for the implantation of OSC in organic complementary logic circuit. To achieve this objective, well-ordered ambipolar semiconducting materials are needed. In this work we investigated the self-organization and the electronic properties of a series of side chain liquid crystal (SCLC) semiconducting polymers where: (i) the backbone is a π-conjugated polymer and (ii) the side-groups are π-conjugated calamitic mesogens. We present our results on the design, synthesis, and structural characterization of this new liquid crystal regioregular poly(3-alkylthiophene) polymer family post-functionalized with side-on calamitic moieties. The parameters of these materials are: (i) the chemical nature of the side-group moieties and (ii) the degree of polymerization. As a result we will show that this strategy leads to the supramolecular self-assembly of this SCLC semiconducting polymer in a peculiar lamello-lamellar mesophase, where the two different lamellas present two different electronic properties, such as electron donor and electron acceptor behaviors
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NAVARRO, RODRIGUEZ DAMASO. "Pyridines et poly-(4-vinylpyridines) quaternisees par des groupes mesogenes. Synthese, caracterisation et etude de leurs proprietes liquide-cristallines." Université Louis Pasteur (Strasbourg) (1971-2008), 1990. http://www.theses.fr/1990STR13140.
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Ce travail decrit la synthese et l'etude des proprietes liquide-cristallines thermotropes d'une serie homologue de molecules de pyridinium obtenues par la quaternisation de la pyridine avec le mesogene methoxybiphenyle et les espaceurs d'halogenure d'alkyle de plusieurs longueurs. Il decrit aussi la synthese et les proprietes mesomorphes des poly-4-vinylpyridines 100% et partiellement quaternises avec ces alkyl-mesogenes. La caracterisation a ete effectuee par microscopie optique, par dsc et par diffraction des rayons x. Ces produits presentent des phases smectiques monocouches (a, b et e). Des modeles d'arrangement moleculaire sont proposes. Ceux-ci tiennent compte de la position relative des trois parties qui composent les molecules et qui s'organisent pour former les couches smectiques, ainsi que du placement de la chaine macromoleculaire dans le cas de polymeres 100% greffes. En ce qui concerne les polymeres partiellement quaternises, les noyaux non-quaternises se placent entre les lamelles. L'arrangement a l'interieur des couches est similaire a celui des molecules pyridinium et des polymeres 100% greffes, a l'exception de certaines phases smectiques monocouches a molecules inclinees qui apparaissent selon la temperature et le taux de greffage
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Hoang, Huong. "Hydroquinone-based Poly(arylene ether)s with Pendent Benzothiazole Or Benzoxazole and 3-sulfonated Phenyl Sulfonyl Groups for Use as Proton Exchange Membranes." Wright State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=wright1376481513.
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Badami, Anand Shreyans. "Morphological and Structure-Property Analyses of Poly(arylene ether sulfone)-Based Random and Multiblock Copolymers for Fuel Cells." Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/29469.
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The commercialization of proton exchange membrane (PEM) fuel cells depends largely upon the development of PEMs whose properties are enhanced over current perfluorinated sulfonic acid PEMs. Understanding how a PEMâ s molecular weight and morphology affect its relevant performance properties is essential to this effort. Changes in molecular weight were found to have little effect on the phase separated morphologies, water uptake, and proton conductivities of random copolymers. Changes in block length, however, have a pronounced effect on multiblock copolymers, affecting surface and bulk morphologies, water uptake, proton conductivity, and hydrolytic stability, suggesting that multiblock copolymer PEM properties may be optimized by changes in morphology.
A major goal of current proton exchange membrane fuel cell research involves developing high temperature membranes that can operate at ~120 °C and low humidites. Multiblock copolymers synthesized from 100% disulfonated poly(arylene ether sulfone) (BPSH100) and naphthalene polyimide (PI) oligomers may be an alternative. At block lengths of ~15 kg/mol they displayed no morphological changes up to 120 °C or even higher. Water desorption was observed to decrease with increasing block length. The copolymers exhibited little to no water loss during a 200 °C isotherm in contrast to random BPSH copolymers and Nafion. A BPSH100-PI multiblock copolymer with large block length appears to have morphological stability and retain water at temperatures exceeding 120 °C, suggesting its candidacy as a high temperature PEM.
A growing number of alternative PEM research efforts involve multiblock copolymer chemistries, but little emphasis is placed on the methods used to couple the oligomers. Fluorinated linkage groups can help increase block efficiency during coupling, but their effect on a PEM is not well-known. The choice of linkage type, hexafluorobenzene (HFB) vs. decafluorobiphenyl (DFBP), appears to have small but observable influences on multiblock copolymers with disulfonated and unsulfonated poly(arylene ether sulfone) oligomers. DFBP linkages promote greater phase separation than HFB linkages, resulting in increased stiffness, decreased ductility, and increased proton conductivity at low humidities. DFBP linkages also promote more surface enrichment of fluorine, causing changes in surface morphology and slightly increased water desorption, but determining the impact on actual fuel cell performance requires further research.Ph. D.
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Friggeri, Arnaud. "Rôle extranucléaire de HMGB1 (High Mobility Group Box 1) au cours de l'efferocytose (phagocytose de cellules apoptotiques)." Amiens, 2012. http://www.theses.fr/2012AMIED004.
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La clairance des cellules apoptotiques appelée efferocytose est un mécanisme complexe participant à l’homéostasie des êtres pluricellulaires. Son dysfonctionnement est associé à des maladies inflammatoires aiguës et chroniques ainsi qu’autoimmunes. La reconnaissance de la phosphatidylsérine (PS) à la surface des cellules apoptotiques par les phagocytes prévient la libération de leur contenu cytotoxique. Au cours de pathologies comme le syndrome de détresse respiratoire aigu (SDRA) on observe une accumulation de cellules apoptotiques dans le tissu pulmonaire. High mobility group box 1 (HMGB1) est une molécule aux propriétés pro-inflammatoires et chémo-attractantes, libérée dans le milieu extracellulaire après modification post-transcriptionnelle comme une acétylation ou une phosphorylation. Sa concentration plasmatique est élevée dans de nombreuses pathologies comme le sepsis et le SDRA. Son administration dans des modèles animaux induit des lésions pulmonaires similaires à celles du SDRA alors que l’utilisation d’anticorps anti-HMGB1 les prévient. But : ces expériences ont été réalisées afin d’explorer le rôle d’HMGB1 au cours de l’efferocytose. Résultats : HMGB1 en se liant à l’intégrine αVβ3 à la surface des macrophages inhibe l’efferocytose. La délétion de l’extrémité C-terminale d’HMGB1 n’altère pas sa capacité à se lier à αVβ3 mais lui fait perdre une partie de ses propriétés inhibitrices en la rendant incapable de se fixer au récepteur aux Advanced Glycation Endoproducts (RAGE) qui participe à l’efferocytose en se liant à PS. La stimulation par le LPS, un ligand de TLR4, induit la libération dépendante de la Poly (ADP) Ribose Polymerase 1 (PARP1) d’HMGB1 ribosylé. Cette ribosylation augmente la capacité d’HMGB1 à se lier à RAGE et à PS et ainsi d’inhiber l’efferocytose. Conclusion : HMGB1 a un effet pro-inflammatoire en inhibant l’efferocytose. HMGB1 se lie sur la surface des phagocytes à l’intégrine αVβ3 et à RAGE qui est un récepteur à PS nouvellement décrit. La ribosylation d’HMGB1 intensifie la propriété inhibitrice d’HMGB1 sur l’efferocytose.
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Manandhar, Prakash. "Understanding the Functional Group-dependent Self-assembly and Cellular Entry of Cationic Conjugated Polymer Nanoparticles." FIU Digital Commons, 2018. https://digitalcommons.fiu.edu/etd/3673.
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Highly fluorescent conjugated polymers (CPs) are an important class of biomaterials used for various biological applications including labelling, sensing, and delivery of biological substances. Synthetic versatility and tunable emission make CPs a superior class of biomaterials. Understanding the structure-function relationship of CPs plays a vital role in designing high performing biomaterials. The cationic CPs are self-assembled to conjugated polymer nanoparticles (CPNs) in an aqueous environment due to their amphiphilicity. The physical and biophysical properties of CPNs are highly dependent on the chemical functionality and backbone structure of CPs. Modulation of the surface property and backbone structure of CPNs play an important role for efficient internalization of CPNs into cells. The goal of this dissertation is to understand the structure function relationship of CPNs in an aqueous environment and the change in their photo physical properties upon the self-assembly of CPNs with different backbone structure upon complexation with biologically significant polysaccharides and cell membrane.
This work presents the self-assembly of a set of four cationic CPs with different connectivity and backbone structure upon complexation with a linear polyanion hyaluronic acid (HA). The study of photo physical properties changes upon the complexation with series of Glycosaminoglycans (GAGs) provides more insight about how the self-assembly behavior of cationic CPs changes upon the exposure to negatively charged polysaccharides. The understanding of the self-assembly of CPNs with negatively charged biologically important macromolecules under in vitro conditions can give us an idea of photophysical property changes of CPNs during the treatment of CPNs in the cellular environment. The study of the interaction of CPNs with cell membranes using scanning ion conductance microscopy (SICM)-based topography, potential mapping, and confocal microscopy imaging is presented. CPNs are able to induce transient pore like feature formation on the cell membrane during the cellular internalization process. A comparative study of cellular labelling and delivery of siRNA of five CPNs with guanidine motif is presented. The subcellular localization and delivery of siRNA were dependent on the side chain hydrophilicity. The CPNs fabricated with hydrophilic aminoethoxyethanol possesses excellent cellular imaging with higher siRNA delivery.
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D'Orazio, Anthony Emidio. "SCALING OF INDIVIDUAL BEHAVIOR TO GROUP DYNAMICS: THEORETICAL AND EXPERIMENTAL CONCERNS WITH REGARD TO POLYP AND CLONE BEHAVIOR IN ANTHOPLEURA ELEGANTISSIMA." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1337634557.
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Kalisch, Thomas. "Caractérisation fonctionnelle et biochimique d'un nouveau partenaire de la poly(ADP-ribose) polymérase I : high-mobility group protein containing 2-like 1." Thesis, Strasbourg, 2013. http://www.theses.fr/2013STRAJ068.
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La poly(ADP-ribosyl)ation est une modification post-traductionnelle des protéines catalysée par une famille d’enzymes : les poly(ADP-ribose) polymérases. Parmi les plus étudiées, PARP-1 et PARP-2 interviennent dans l’organisation, l’expression et le maintien de l’intégrité du génome. Nous avons initié l'étude d'un nouveau partenaire de PARP-1 préalablement identifié par double-hybride, et encore peu étudié à ce jour : HMG2L1 (High-Mobility Group protein 2 Like-1). La protéine humaine de 601 acides aminés contient un domaine HMG (High-Mobility Group) normalement impliqué dans l’interaction avec l’ADN. Quelques études ont montré que HMG2L1 régule la transcription en agissant comme co-régulateur négatif ou positif. Dans un premier temps, nous avons caractérisé le lien entre PARP-1 et HMG2L1. L’interaction avec PARP-1 a été confirmée in-vivo et in vitro. Nous avons montré que HMG2L1 pouvait également interagir avec PARP-2. HMG2L1 est poly(ADP-ribosyl)ée par PARP-1 et PARP-2, de même qu’elle est capable d’interagir avec le poly(ADP-ribose). La construction de formes tronquées de HMG2L1 en fusion avec la GFP nous a permis de montrer que le domaine N-terminal – en amont du domaine HMG – est impliqué dans ces interactions. Ce domaine N-terminal est très électropositif et intrinsèquement désordonné ce qui lui confère de nombreuses potentialités d’interactions. L’expression des fusions GFP dans des cellules HeLa nous a permis de montrer la localisation nucléaire et nucléolaire de HMG2L1, comme c’est le cas pour PARP-1 et PARP- 2. En outre, HMG2L1 colocalise avec UBF (Upstream Binding Factor), le facteur de transcription de l’ARN polymérase I responsable de la transcription des ARN ribosomaux. La surexpression de GFP-hHMG2L1 entraîne un stress nucléolaire caractérisé par l’inhibition de la transcription des ADNr et la formation de coiffes nucléolaires. Nous avons également entrepris une recherche de partenaires de HMG2L1 par spectrométrie de masse. De nombreuses protéines nucléolaires, impliquées dans la biogenèse des ribosomes ou la maturation des ARNs ont été identifiées, suggérant un rôle de HMG2L1 dans ces processus. Nous avons montré que la protéine purifiée interagit avec l’ADN via son domaine HMG principalement, et qu’elle interagit avec l’ARN via son domaine N-terminal. Mais surtout, nous avons mis en évidence une activité ARN-chaperonne, qui peut être régulée par le poly(ADP-ribose). La localisation de HMG2L1, son réseau d’interaction ainsi que son activité chaperonne nous laissent à penser qu’elle pourrait être impliquée dans des processus de maturation des ARN, régulés par la poly(ADPribosyl)ationPoly(ADP-ribosyl)ation is a post-translational modification of proteins mediated by a family of enzymes called poly(ADP-ribose) polymerases. Among the best studied, PARP-1 and PARP-2 are both implicated into the transcription, organization and integrity of genome. We have initiated the characterization of a new PARP-1 partner previously identified in a yeast two-hybrid screen, and still poorly studied: HMG2L1 (High-Mobility Group protein 2 Like-1). The human protein of 601 amino acids contains one HMGbox domain normally implicated in the recognition of DNA. Some studies have reported the role of HMG2L1 in the regulation of transcription by acting as a negative or positive coregulator. First, we characterized the link between PARP-1 and HMG2L1. We confirmed the interaction between both proteins in vivo and in vitro. We also showed that HMG2L1 couldinteract with PARP-2. HMG2L1 is poly(ADP-ribosyl)ated by PARP-1 and PARP-2, and is able to interact with poly(ADP-ribose). The construction of GFP-fused truncated versions of HMG2L1 allowed us to show that the N-terminal part – upstream to the HMGbox – is responsible for all these interactions. This N-terminal domain is highly electropositive and intrinsically disordered conferring a lot of interactions potentialities. The expression of the GFP-fused proteins in HeLa cells allowed us to localizeHMG2L1 into the nucleus and the nucleolus, like PARP-1 and PARP-2. Moreover, HMG2L1 colocalizes with UBF (Upstream Binding Factor), the transcription factor responsible for the transcription of ribosomal ARNs by RNA polymerase I. The overexpression of GFPhHMG2L1 leads to a nucleolar stress illustrated by the inhibition of transcription and the formation of nucleolar caps. We also undertook a proteomic study to find new partners of HMG2L1. We found a huge amount of nucleolar proteins, involved in ribosome biogenesis or RNA maturation, suggesting that HMG2L1 could be involved in these processes. Finally, we demonstrated the ability of the purified protein to interact with DNA mostly through its HMGbox domain and RNA through its N-terminal domain. Moreover, we discovered that HMG2L1 is endowed with a RNA-chaperone activity, that can be regulated by poly(ADP-ribose). Taken together, the localization of HMG2L1, its interacting partners and its RNA chaperone activity allow us to make the assumption that HMG2L1 could be implicated in RNA maturation processes, regulated by poly(ADP-ribosyl)ation
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Vaca, Melissa Mariana Gómez. "Avaliação da eficiência de obtenção, proliferação, senescência e plasticidade das células-tronco da polpa de dentes permanentes humanos em diferentes faixas etárias." Universidade Federal de Juiz de Fora (UFJF), 2017. https://repositorio.ufjf.br/jspui/handle/ufjf/5707.
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O tecido da polpa do dente é uma fonte promissora para a obtenção de células tronco, as Dental Pulp Stem Cells (DPSCs) e seu posterior uso em terapias regenerativas, por isso torna-se importante saber a melhor idade do doador para seu armazenamento. Desta forma, o presente estudo buscou avaliar a eficiência na obtenção, proliferação, senescência e plasticidade das DPSCs em diferentes faixas etárias. Foram obtidas polpas dentarias de dentes molares extraídos, que compuseram três grupos: GI (18 – 33 anos), GII (34 – 49 anos) e GIII (50 – 67 anos). O isolamento celular foi avaliado através da observação microscópica diária do tecido pulpar e das células provenientes da polpa, por 15 dias. A proliferação celular foi analisada pelo ensaio de MTT nos dias 3, 5 e 7. A senescência das DPSCs foi feita em triplicata com contagem celular a cada 2 dias. A plasticidade celular foi realizada através da indução a diferenciação osteogênica, odontogênica e adipogênica. Os resultados apontaram que a eficiência da obtenção das DPSCs foi maior no GI, com decrescimento progressivo para GII e GIII. Não houve diferença estatística entre os grupos testados na avaliação da proliferação celular e na senescência. Amostras dos 3 grupos avaliados demostraram ter capacidade de diferenciação celular. Pode-se concluir que a idade foi capaz de influenciar a obtenção de DPSCs, apontando a faixa etária de 18 a 33 anos de idade (GI), como o grupo mais eficiente, já que o 100% das polpas dentarias deram células. Entretanto, ao avaliar a proliferação, senescência e plasticidade celular, todos os grupos se comportaram dentro de um mesmo padrão, sem a interferência da idade do doador.
The pulp tissue of the tooth is a promising source for obtaining stem cells, the Dental Pulp Stem Cells (DPSCs) and their subsequent use in regenerative therapies, so it becomes important to know the best age of the donor for its storage. In this way, the present study sought to evaluate the efficiency in obtaining, proliferating, senescence and plasticity of DPSCs in different age groups. Dental pulps of extracted molar teeth were obtained, which comprised three groups: GI (18 - 33 years), GII (34 - 49 years) and GIII (50 - 67 years). Cellular isolation was evaluated by daily microscopic observation of pulp tissue and pulp cells for 15 days. Cell proliferation was analyzed by the MTT assay on days 3, 5 and 7. Senescence of the DPSCs was done in triplicate with cell counts every 2 days. Cellular plasticity was achieved through the induction of osteogenic, odontogenic and adipogenic differentiation. The results showed that the efficiency of obtaining DPSCs was higher in the GI, with progressive decrease for GII and GIII. There was no statistical difference between the groups tested in the evaluation of cell proliferation and senescence. Samples of the 3 groups evaluated showed to be cell differentiation capacity. It can be concluded that age was able to influence the achievement of DPSCs, pointing to the age group of 18 to 33 years of age (GI), as the most efficient group, since 100% of the pulps gave cells. However, when evaluating cell proliferation, senescence and plasticity, all groups behaved within the same pattern, without interference from donor age.
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Varray, Stéphane. "Utilisation du support poly(éthylène glycol) dans la synthèse d'aminoacides et de peptides cycliques par métathèse des oléfines." Montpellier 2, 2001. http://www.theses.fr/2001MON20191.
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Serpa, Giulliano Caixeta. "Oximetria de pulso na determinação da saturação de oxigênio de pré-molares em diferentes faixas etárias." Universidade Federal de Goiás, 2015. http://repositorio.bc.ufg.br/tede/handle/tede/7268.
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Objective: The aim of this study was to establish the level of oxygen saturation in normal pulps of premolars maxilary in different age groups. Methodology: 120 premolars were selected in normal conditions and pulp divided by age of 24 teeth each: 20-24 years; 25-29 years; 30-34 years; 35-39 years; 40 to 44 years. the level of oxygen saturation of these teeth was determined by pulse oximetry. The ANOVA was used to check for differences between these age groups in the level of oxygen saturation and the Tukey test to identify which differed from each other. Results: The mean oxygen saturation encompassing all age groups was 86,2%, already for each separately it was found that: 20-24 years (89,71%), 25-29 years (87,67%) 30 to 34 years (88,71%), 35-39 years (84,80%), 40-44 years (80,00%), with the latter being statistically significant reduced level of others. Conclusion: The oxygen saturation level in normal pulps premolars averaged 86.2%, a significant reduction from 40 to 44 years.
Objetivo: Estabelecer o nível de saturação de oxigênio em polpas normais de pré-molares em diferentes faixas etárias. Material e Método: Foram selecionados 120 pré-molares superiores humanos em condições pulpares de normalidade e divididos por faixa etária (n=24): 20 a 24 anos; 25 a 29 anos; 30 a 34 anos; 35 a 39 anos; 40 a 44 anos. O nível de saturação dos dentes foram avaliados por um oximetro de pulso. A análise de variância ANOVA foi utilizada para verificar a existência de diferença entre as faixas etárias em relação ao nível de saturação de oxigênio, e o teste de Tukey para identificar quais diferiam entre si. Resultados: A média de saturação de oxigênio em todas as faixas etárias foi de 86,2%. A análise dos valores obtidos em cada faixa sugere que na última faixa etária verificou-se um nível reduzido, significante em relação as demais [(20 a 24 anos (89,71%); 25 a 29 anos (87,67%); 30 a 34 anos (88,71%); 35 a 39 anos (84,80%); 40 a 44 anos (80,00%)]. Conclusão: O nível de saturação de oxigênio em polpas normais de pré-molares apresentou uma média de 86,2%, com redução significante entre 40 a 44 anos.
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Monte, Pérez Inés [Verfasser], Kallol [Gutachter] Ray, and Christian [Gutachter] Limberg. "Bioinspired oxidation reactions involving mono- and poly-nuclear transition metal complexes : hydrogen atom abstraction and group transfer reactions / Inés Monte Pérez ; Gutachter: Kallol Ray, Christian Limberg." Berlin : Mathematisch-Naturwissenschaftliche Fakultät, 2017. http://d-nb.info/1129750671/34.
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Kleinfehn, Alex Patrick. "Scale-Up of Modifiable Poly(propylene fumarate) and Surface Functionalization of Additive Manufactured Scaffolds for Bone Tissue Regeneration." University of Akron / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=akron1562679460809562.
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Sadjadi, Seyedabdolreza. "Ab initio relativistic-consistent calculations and charge density and experimental mass-spectroscopic analysis of mono and poly-nuclearclusters of group 11 and 12 transition metals and metal chlorides: ySeyedabdolreza Sadjadi." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hub.hku.hk/bib/B5060577X.
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The electron density function of molecular systems supplies a package of information. Quantum mechanical methods of producing and analyzing this function have been significantly improved during the past few years. The advent of accurate pseudopotentials and corresponding basis sets for Kohn-Sham density functional and for post-Hartree-Fock electron-correlated approaches have enabled the inclusion of scalar relativistic and spin-orbit coupling effects as well as electron correlation effects into the electron density function. The unpacking of the information embedded in such a function via the quantum theory of atoms in molecules (QTAIM) became possible by utilizing the very new subshell fitting method of reconstructing the density distribution of core electrons that had been replaced by the pseudopotentials.
These theoretical advances were applied in this thesis to characterize and explore the topological features of metal-metal bonding as one of the fundamental types of bonds formed between two elements. Group 11 and 12 transition metals which include gold and mercury as the most relativistic elements were the main focus of this work. Mono and poly-nuclear compounds (with up to 4 metal atoms) in both pure metal clusters and chloro-complexes were studied by ab initio MØller-Plesset perturbation calculations followed by QTAIM analysis on the relaxed density. Some of these chloro-complexes of copper, gold, zinc and cadmium metals were identified in the gas phase by mass spectrometric experiments. The general formulas of the set of molecules studied in group 11 were : M2, MCl, MCl+, MCl2, MCl2+, M2Cl+, M2Cl2^(s+), M2Cl3+, M3Cl2+, M3Cl3+, M3Cl5+, M4Cl5+ and M4Cl7+ and in group 12 were : M2, MCl, MCl+, MCl2, M2Cl3+, M3Cl5+, M4Cl7+ and M2^(s+). The topological features of metal-metal bonding were calculated along with atomic properties for each individual local minimum isomer found. The comparison of
the metal-metal bonding within the complexes and with the dimers revealed new
features of metal-metal bonding in 3d, 4d and 5d transition metal elements of
groups 11 and 12. With the aid of strong correlation between bond dissociation
energy and electron density at the location of the bond critical points found in the
case of dimers, the strength of the metal-metal bonding in the complexes was
estimated. The electron density’s basin properties calculated accurately for all the
clusters and their isomers in this thesis provided more insight also into the nature
of M-Cl bondings in the group 11 and 12 chloride clusters. Ultimately the bonding
information was used to predict the viability of these clusters in the gas phase.published_or_final_version
Chemistry
Doctoral
Doctor of Philosophy
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Etheve, Jocelyne. "Corrélation potentiel d'écoulement-concentration interfaciale de protéines à l'interface silice-solution : influence d'un traitement externe par de la poly(éthylèneimine) sur la pénétration du lysozyme à l'intérieur d'une membrane portant des groupes sulfonates." Montpellier 2, 2003. http://www.theses.fr/2003MON20004.
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McIntosh, Blaine. "Shifting attentions in mathematics: developing problem solving abilities through problem-solving groups." 2011. http://hdl.handle.net/1993/4756.
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The purpose of this study was to improve problem solving attitudes and abilities in students of mathematics through the exploration of John Mason’s general problem solving strategy and the use of problem solving groups, and to document and understand this improvement process. The types of problems and tasks assigned to students as well as assessment practices were also examined. A Design-Experiment Research approach was used with thirty grade 9 students participating throughout the year-long study. A teacher-researcher journal, student problem-solving journals, and surveys were used.
The study showed that using a general problem solving strategy with groups of students working together to solve problems can improve problem solving attitudes and abilities. Students made significant improvements during initial engagement of problems, in specializing and generalizing, and in communication. Almost all students expressed a more positive attitude toward problem solving and their problem solving abilities. The study demonstrates how focusing on initial stages of the problem solving process like the understanding of the problem in a group context can reach multiple learning objectives and positively impact later stages of problem solving. In addition, recommendations for classroom teachers are provided concerning the roles within the groups, the nature of beneficial problem types and student tasks, and concerning the role of the teacher as researcher of his or her own teaching practice.
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Chen, Ya-Yin, and 陳雅音. "SYNTHESIS AND PROPERTIES OF NOVEL POLY(ETHER IMIDE)S CONTAINING TRIFLUOROMETHYL GROUPS AND POLY(ETHER NAPHTHALIMIDE)S CONTAINING PHTHALIDE GROUPS." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/16795728160082047558.
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碩士大同大學
化學工程學系(所)
94
Part 1: A series of novel fluorinated poly(ether imide)s (IV) having inherent viscosities of 0.70-1.08 dL/g were prepared from 1,1-bis[4-(3,4-dicarboxyphenoxy)phenyl]cyclohexane dianhydride (I) and various trifluoromethyl (CF3)-substituted aromatic bis(ether amine)s II¬¬a-g by a standard two-step process with thermal and chemical imidization of poly(amic acid) precursors. These poly(ether imide)s showed excellent solubility in many organic solvents and could be solution-cast into transparent, flexible, and tough films. These films were essentially colorless, with an ultraviolet-visible absorption edge of 375-380 nm and a very low b* value (a yellowness index) of 5.5 to 7.3. They also showed good thermal stability with glass-transition temperatures of 207-269 oC, 10% weight loss temperatures in excess of 474 oC, and char yields at 800 oC in nitrogen more than 62%. In comparison with analogous V series poly(ether imide)s without the -CF3 substituents, the IV series polymers showed better solubility, lower color intensity, and lower dielectric constants. Part 2: A series of organosoluble and colorless fluorinated poly(ether imide)s (4a-g) were prepared from 3,6-bis(3,4-dicarboxyphenoxy) benzonorbornane dianhydride (1) and various trifluoromethyl (CF3)-substituted aromatic bis(ether amine)s 2a-g by a standard two-step process with thermal and chemical imidization of poly(amic acid) precursors. These poly(ether imide)s had inherent viscosities of 1.19-1.78 dL/g and showed excellent solubility in many organic solvents. They could be solution-cast into transparent, flexible, and tough films with good mechanical properties. These films were virtually colorless, with an ultraviolet-visible absorption edge of 372-379 nm and a very low b* value (a yellowness index) of 10.8 to 14.1. The glass-transition temperatures (Tg) and softening temperatures (Ts) were recorded between 216-292 oC and 209-285oC, respectively. The decomposition temperature for 10% weight loss all occurred above 479 oC in nitrogen and 467 oC in air, and the char yields at 800 oC in nitrogen were more than 51%. They also showed low dielectric constants of 2.84-3.58 (1 MHz) and moisture absorptions in the range of 0.05-0.19%. In comparison with analogous 5 series poly(ether imide)s without the -CF3 substituents, the 4 series ones showed better solubility, lower color intensity, and lower dielectric constants. Part 3: A series of organic-soluble polynaphthalimides (PNI) bearing flexible ether links and phthalide cardo group were synthesized from 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTDA) with 3,3-bis[4-(4-aminophenoxy)-3-methylphenyl]phthalide (BAMP) and its mixtures with other dietheramines (6b-g) by high-temperature solution polycondensation in m-cresol. The PNIs had moderate to high inherent viscosities in the range of 1.24-2.25 dL/g and could afford flexible and tough films with tensile strengths of 97-138 MPa by casting their m-cresol solutions. These PNIs exhibited high thermal stability, with glass-transition temperature of 291-321 °C, 10% weight-loss temperatures above 542 °C, and char yields at 800 °C in nitrogen higher than 56%. In comparison with PNIs without the BAMP component, these BAMP-modified PNIs revealed an enhanced solubility and film-forming capability.
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Matt, Sonja [Verfasser]. "Polycomb group proteins in the freshwater polyp Hydra / Sonja Matt." 2011. http://d-nb.info/1011486962/34.
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Hsu, Ke-Lun, and 許閣倫. "Crosslinkable sulfonated poly(ether ketone)s containing norbornene groups as proton exchange membrane." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/44163409358432474096.
Full textAbstract:
碩士國立中央大學
化學研究所
96
A series of crosslinkable sulfonated poly(ether ketone)s containing norbornene groups were synthesized by aromatic nucleophilic substitution reaction . To decrease the swelling of fuel cell membranes , crosslinking of theses polymers by radical polymerization were be tested. These polymers had good thermal and oxidative stability , and good dimensional stability in hot water . The proton conductivity of NB-Np SPEEKK at room temperature is 7.52 x 10-2 S/cm. The results showed these materials containing norbornene groups are possible inexpensive candidate materials for proton exchange membranes in fuel cell applications.
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Yeh, Chen-Yu, and 葉振裕. "Poly(propylene oxide) modifications with end-coupling of functional groups for biomedical applications." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/03843612034952230925.
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碩士國立陽明大學
醫學工程研究所
95
The polymer chain of polypropylene oxide (PPO) contains two parts of different properties, one is the major hydrophobic chain PO, the other is the hydrophilic hydroxyl groups located at both ends of PPO. The two hydroxyl groups can be modified to obtain functional active groups. The aims of this study were to synthesize PPO with terminal COOH, CHO and NH2 groups, and thence used to modify collagen and hyaluronic acid. The PPO-COOH polymer was synthesized by PPO reacted with succinic anhydride at 1500c, PPO-CHO was obtained by PPO reacted with the DMSO/Acetic anhydride reagents, and PPO-NH2 was synthesized by PPO-CHO reacted with NH3 followed by the reduction with NaCNBH3. All of the PPO modified products thus obtained were confirmed by the data of FT-IR and NMR. The resulted PPO-COOH polymer and a commercial PPO-NH2 polymer were used to couple to collagen and hyaluronic acid, respectively. The carboxylic acid of PPO-COOH was activated by 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide hydrochloride (EDC)/ N-hydroxysuccinimide (NHS) and reacted with the amino groups of collagen fibrils. The resulted collagen-PPO was identified by IR absorption peak at 1100cm-1 (C-O), 1700cm-1 (C=O) and 2950cm-1 (CH3) and the slower mobility of collagen-PPO as shown in the SDS-PAGE. The coupling of 2HN-PPO-NH2 to HA was confirmed by absorption peak of PPO (fingerprint of PPO 800~1200 cm-1) in HA-PPO FT-IR spectra and the peak of PPO methyl group (around 1.2ppm) in HA-PPO NMR spectra. The PPO derivatives synthesized in this study could be very useful for the modifications of other biopolymers.