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1
Tee, Abigail. "Acknowledging individual strengths, interests and needs of pupils with Autistic Spectrum Conditions : questioning 'Theory of Mind' (a pilot study)". Thesis, Cardiff University, 2016. http://orca.cf.ac.uk/95513/.
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Research investigating children and young people’s (CYP’s) performance in standard False Belief (FB) tasks, such as ‘The Sally Anne Task’ has highlighted that CYP with autistic spectrum condition (ASC) have difficulties in passing the task and demonstrating Theory of Mind (ToM), in comparison to CYP with ‘neurotypical’ development. This finding has led to the suggestion that individuals with ASC may have deficits in their ToM (Baron-Cohen, Leslie & Frith, 1985). The present research aimed to explore whether there were differences in the performance of pupils with ASC on ‘The Sally-Anne Task’ compared to an adapted task, which was tailored to the individual’s strengths, interests and areas of need (via information from a template about the pupil supplied by helpers). Nineteen pupils with a diagnosis of ‘autistic spectrum disorder’ between the ages of 6 and 10 years (mean = 8.47 years, standard deviation = 1.12 years) were recruited from mainstream classrooms or specialist resource bases attached to mainstream classrooms in three Welsh and five English primary schools. A pragmatic research framework employed a within subjects design; each pupil took part in the two (counterbalanced) tasks. A McNemar’s Exact test revealed a significant difference between the pass rates of pupils in the standard and adapted tasks (p = .008). Pupils in the adapted tasks were almost twice as likely to pass the tasks (M = .89, SD = .31) as those in the standard tasks (M = .47, SD = .51). Implications for understanding ToM in pupils with ASC are discussed and suggestions for developing support, which focuses on the individual’s strengths and interests, are proposed.
2
Wiedenheft, Blake Alan. "Sulfolobus as a model organism for the study of diverse biological interests forays into thermal virology and oxidative stress /". Diss., Montana State University, 2006. http://etd.lib.montana.edu/etd/2006/wiedenheft/WiedenheftB1206.pdf.
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Miketova, Petra 1967. "Mass spectrometry of compounds of biological interest". Diss., The University of Arizona, 1998. http://hdl.handle.net/10150/288810.
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Mass spectrometric methods, including EI, CI, FAB and ESI LC/MS have been surveyed as tools for identification and characterization of compounds of natural origin exhibiting biological activity. Bioactive catechins isolated from green tea were analyzed by mass spectral methods: EI spectra provided both molecular weight and structural information, including epimer differentiation. FAB mass spectrometry gave both molecular weight and structural information on all compounds. ESI LC/MS provided unambiguous MW information on all compounds and some additional structural data on compounds ECG and EGCG. ESI LC/MS provided a means for separation of all compounds in a mixture and is an appropriate method for analysis of a crude extract of this plant material. Based on the result from biological testing, showing that quinic acid derivatives possess considerable anti-HIV activity, four analogs of dicaffeoylquinic acid were characterized by mass spectral methods. An attempt was made to design a mass spectral method allowing the differentiation between the analogs. FAB mass spectral analysis provided good MW information for all compounds. In addition, ions representing the elimination of water from MH+ ion of the 3,5-DCQA-OAc clearly differentiated this isomer from the 3,4-DCQA-OAc. MIKES analysis of the MH+ ions of the acetate derivative confirmed the isomer specific water loss. ESI provided unambiguous MW information on all compounds, confirming that loss of water is specific for the 3,5-DCQA-OAc. The extract of the CSF in patients with ALL was surveyed for a suitable biomarker which would indicate brain tissue damage following therapy. Phospholipid levels in CSF in three groups of patients receiving different CNS propylaxis were monitored during the course of treatment and the elevated levels were correlated to the cognitive impairment evaluation results. As a result of the CNS propylaxis, the levels of phospholipids in CSF are significantly elevated, indicating disruption of brain cell membranes. Two major classes of phospholipid were identified by FAB mass spectral analysis, PC and SM. Their elevated levels were inversely correlated with the decreased scores from cognitive testing. A close correlation was found between the PC levels and some test scores.
4
Birch, Nicola Jayne. "A novel route to iminosugars of biological interest". Thesis, University of Sussex, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.430365.
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Desai, Trupti. "The chemistry of inositol compounds of biological interest". Thesis, University College London (University of London), 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304867.
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Strawbridge, Sharon Mary. "Redox-active sensors for molecules of biological interest". Thesis, University of Exeter, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.414263.
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Barnes, Samuel. "Synthesis of 2,4-Disubstituted Pyrimidines of Possible Biological Interest". Digital Archive @ GSU, 2008. http://digitalarchive.gsu.edu/chemistry_theses/10.
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The synthesis of 2,4-disubstituted pyrimidine derivatives is described. The synthetic route involved the addition reaction of lithiated intermediates, mostly heterocycles, to position 4 of 2-chloropyrimidine to give a dihydropyrimidine intermediate which was oxidized back to a pyrimidine. This was followed by nucleophilic aromatic substitution with various amines of the chlorine in the position 2. A number of compounds were prepared which showed binding towards various serotonin receptors in preliminary biological evaluation.
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Quiroz, Alejandro. "Deciphering the Biological Mechanisms Driving the Phenotype of Interest". Thesis, Harvard University, 2012. http://dissertations.umi.com/gsas.harvard:10708.
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The two key concepts of Neo-Darwinian evolution theory are genotype and phenotype. Genotype is defined as the genetic constitution of an organism and phenotype refers to the observable characteristics of that organism. Schematically the relationship between genotype and phenotype can be settled as Genotype + Environment + Random Variation \(\underrightarrow{\text{yields}}\) Phenotype. This schematic representation has led to the fundamental problem of given the interactions of the genes and environment, up to what extent is possible to establish a relationship between gene structure and function to the phenotype (Weatherall, D. J., et. al., (2001)). Since R. A. Fisher establishing the basis of quantitative trait loci up to the work of Subramanian, et. al., (1995) gene set enrichment analysis, several statistical methods have been devoted to answer this question, some with more success and scientific repercussion than others. In this work we attempt to answer to this question by delineating the biological mechanisms driven by the genes that are characterize the differences and actions of the phenotypes of interest. Our contribution resides on two pillars: we present an alternative way to conceive gene expression measurements and the use of functional gene set annotation systems as guided prior knowledge of the biological mechanisms that drive the phenotype of interest. Based on these two pillars we propose a method to infer the Functional Network Inference and an alternative method to perform expression Quantitative Trait Loci analysis. (eQTL) From the Functional Network Inference method we are able to identify what mechanisms describe the behavior of most of the, there fore establishing its importance. The alternative method to perform eQTL analysis that we present, is more direct way to associated variations at a sequence level and the biological mechanisms it affects. With this proposal we attempt to address two important issues of traditional eQTL analysis: statistical power and biological implications.
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Wood, Stephen Derek. "Crystallographic studies of molecules of biological and chemical interest". Thesis, Liverpool John Moores University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337886.
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Lineros, Rosa Mauricio. "Photoremovable protecting groups for carbonyl compounds of biological interest". Doctoral thesis, Universitat Politècnica de València, 2021. http://hdl.handle.net/10251/167764.
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[ES] El espectro de la luz solar está compuesto por una amplia gama de radiaciones electromagnéticas las cuales tienen diferentes impactos sobre la vida en la tierra. Entre ellas, las pertenecientes a la región ultravioleta toman un papel principal cuando nos referimos a la fotobiología, ya que pueden interactuar con las biomoléculas por medio de procesos tanto directos como fotosensibilizados. Como resultado, estas biomoléculas pueden sufrir modificaciones que no siempre tienen efectos beneficiosos. En este contexto, los daños fotoinducidos al ADN son de gran relevancia ya que están estrechamente relacionados con la creciente incidencia de cáncer de piel. Por ello, es necesario investigar tanto los mecanismos involucrados en dichos procesos como el desarrollo de nuevas estrategias para combatirlos. En la presente tesis se da respuesta a estas necesidades mediante el desarrollo y empleo de grupos protectores fotolábiles (PPG).
En una primera parte se avanza en el desarrollo de nuevos PPG basados en filtros solares. Estos ofrecen la ventaja de actuar, una vez liberados, como un escudo protector frente a la radiación ultravioleta. En este contexto, en el Capítulo 3 se profundiza en las propiedades fotofísicas y fotoquímicas de los sistemas formados por la avobenzona como PPG de ácidos carboxílicos, más concretamente del ketoprofeno (KP) y del naproxeno (NPX). En este estudio se analiza por medio de modelado molecular y técnicas espectroscópicas la influencia que tiene la energía relativa del triplete de la avobenzona en su forma dicetónica, 3AB(K)*, respecto a la de los compuestos protegidos en el proceso de liberación. Siguiendo en esta misma línea de trabajo, en el Capítulo 4 se ha desarrollado un nuevo PPG capaz de liberar el filtro solar oxibenzona (OB) junto con compuestos carbonílicos.
En una segunda parte, el foco de atención se ha puesto en el concepto de "Caballo de Troya", el cual establece que ciertas lesiones del ADN pueden actuar a su vez como fotosensibilizadores endógenos generando así nuevas lesiones en su entorno. En este contexto, en el Capítulo 5 se han estudiado, mediante métodos tanto experimentales como teóricos, las propiedades fotosensibilizantes de dos de los daños oxidativos del ADN, el 5-formiluracilo (ForU) y la 5-formilcitosina (ForC), poniendo especial énfasis en la capacidad de estos para poblar sus estados tripletes, así como de inducir la formación fotosensibilizada de dímeros ciclobutánicos de pirimidina (CPD). Por último, en el Capítulo 6 se ha desarrollado una nueva alternativa sintética para la incorporación del ForU en oligonucleótidos. Debido a la inestabilidad del grupo aldehído, esta síntesis se lleva a cabo generalmente mediante la incorporación de un precursor el cual es posteriormente convertido en el ForU mediante la acción de un agente oxidante. Por el contrario, en la nueva alternativa planteada el aldehído es protegido con un PPG, de manera que una vez insertado en el ODN, el aldehído es liberado de forma selectiva mediante el empleo de luz. Este trabajo supone un avance en el estudio de las propiedades fotosensibilizantes del ForU ofreciendo una nueva herramienta para la evaluación de las mismas en un entorno más cercano al del ADN.[CA] L'espectre de la llum solar està compost per una àmplia gamma de radiacions electromagnètiques les quals tenen diferents impactes sobre la vida en la terra. Entre elles, les pertanyents a la regió ultraviolada prenen un paper principal quan ens referim a la fotobiologia, ja que poden interactuar amb les biomolècules per mitjà de processos tant directes com fotosensibilitzats. Com a resultat, aquestes biomolècules poden patir modificacions que no sempre tenen efectes beneficiosos. En este context, els danys fotoinduits a l'ADN són de gran rellevància ja que estan estretament relacionats amb la creixent incidència de càncer de pell. Per això, és necessari tant d'investigar els mecanismes involucrats en els processos com el desenvolupament de noves estratègies per a combatre'ls. En la present tesi es dóna resposta a aquestes necessitats per mitjà del desenvolupament i ús de grups protectors fotolàbils (PPG). En una primera part s'avança en el desenvolupament de nous PPG basats en filtres solars. Estos ofereixen l'avantatge d'actuar, una vegada alliberats, com un escut protector enfront de la radiació ultraviolada. En este context, en el capítol 3 s'aprofundeix en les propietats fotofísiques i fotoquímiques dels sistemes formats per l'avobenzona com PPG d'àcids carboxílics, més concretament del ketoprofé (KP) i del naproxé (NPX). En este estudi s'analitza per mitjà de modelatge molecular i tècniques espectroscòpiques la influència que té en el procés d'alliberament l'energia relativa del triplet de l'avobenzona en la seua forma dicetònica, 3AB(K)*, respecte a la dels compostos protegits. En esta mateixa línia de treball, en el capítol 4 s'ha desenvolupat un nou PPG capaç d'alliberar el filtre solar oxibenzona (OB) junt amb compostos carbonílics. En una segona part, el focus d'atenció s'ha posat en el concepte de "Cavall de Troia", el qual estableix que certes lesions de l'ADN poden actuar al seu torn com fotosensibilitzadors endògens generant així noves lesions en el seu entorn. En este context, en el capítol 5 s'han estudiat, per mitjà de mètodes tant experimentals com teòrics, les propietats fotosensibilitzants de dos dels danys oxidatius de l'ADN, el 5-formiluracil (ForU) i la 5-formilcitosina (ForC), posant especial èmfasi tant en la capacitat d'estos per a poblar els seus estats triplet, com d'induir la formació fotosensibilitzada de dímers ciclobutànics de pirimidina (CPD). Finalment, en el capítol 6 s'ha desenvolupat una nova alternativa sintètica per a la incorporació del ForU en oligonucleòtids. A causa de la inestabilitat del grup aldehid, esta síntesi es duu a terme generalment per mitjà de la incorporació d'un precursor el qual és posteriorment convertit en el ForU per mitjà de l'acció d'un agent oxidant. Al contrari, en la nova alternativa plantejada l'aldehid és protegit amb un PPG, de manera que una vegada inserit en l'oligonucleòtid, l'aldehid és alliberat de forma selectiva per mitjà de l'ús de llum. Este treball suposa un avanç en l'estudi de les propietats fotosensibilitzants del ForU i ofereix una nova ferramenta per a l'avaluació de les mateixes en un entorn més pròxim al de l'ADN.
[EN] The solar spectrum is composed of a wide range of electromagnetic radiations which have different impacts on life on earth. Among them, those belonging to the ultraviolet region are of utmost importance when we refer to photobiology, since they can interact with biomolecules through both direct and photosensitized processes. As a result, these biomolecules can undergo modifications that do not always have beneficial effects. In this context, photoinduced DNA damage is of great relevance as it is closely related to the increasing incidence of skin cancer. Therefore, it is necessary both to investigate the mechanisms involved in these processes and to develop new strategies to avoid them. In this Thesis these issues have been addressed through the development and use of photolabile protecting groups (PPG). The first part of this Thesis involves the development of new PPG based on solar filters. Once released, these PPG offer the advantage of acting as ultraviolet shields. In this context, Chapter 3 looks into the photophysical and photochemical properties of those systems formed by avobenzone as PPG of carboxylic acids, more specifically ketoprofen (KP) and naproxen (NPX). In this study, the influence on the photorelease process of the relative energetic location of the avobenzone triplet manifold in its diketo form, 3AB(K)*, with respect to that of its caged compound, is duly analyzed by means of molecular modeling and spectroscopic techniques. Following this same line of work, a new PPG capable of releasing oxybenzone (OB) solar filter along with carbonyl compounds has been developed in Chapter 4. The second part of this Thesis focuses on the "Trojan Horse" concept, which establishes that certain DNA lesions can act as endogenous photosensitizers, thus generating new lesions in their neighborhood. In this context, in Chapter 5 the photosensitizing properties of two oxidatively generated DNA damages, namely 5-formyluracil (ForU) and 5-formylcytosine (ForC), have been studied by means of experimental and theoretical approaches. Here, special emphasis has been placed on unraveling their capacity to photoinduce the formation of cyclobutane pyrimidine dimers (CPD). Finally, in Chapter 6 a new synthetic alternative for the incorporation of ForU into oligodeoxynucleotides (ODN) has been developed. Due to the instability of the aldehyde group, this synthesis is generally carried out by incorporating a precursor which is subsequently converted into ForU by the action of an oxidative agent. On the contrary, in the new approach, the aldehyde is protected with a PPG, so that once inserted into the ODN, the aldehyde is selectively released through the use of light. This work entails a step forward in the study of the photosensitizing properties of ForU, offering a new tool for their evaluation within the DNA environment.
Lineros Rosa, M. (2021). Photoremovable protecting groups for carbonyl compounds of biological interest [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/167764
TESIS
11
Alexopoulos, Eftichia. "Crystallographic and modeling studies of intermolecular interactions of biological interest". Doctoral thesis, [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=972659137.
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Barnes, Samuel. "Synthesis of 2, 4-distributed pyrimidines of possible biological interest". unrestricted, 2008. http://etd.gsu.edu/theses/available/etd-05012008-164917/.
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Thesis (M.S.)--Georgia State University, 2008.Title from file title page. Lucjan Strekowski, committee chair; A.L. Baumstark, Jerry Smith, committee members. Electronic text (83 p. : ill.) : digital, PDF file. Description based on contents viewed August 8, 2008. Includes bibliographical references (p. 44-46).
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Holland, Susan Katrina. "X-ray studies of proteins of medical and biological interest". Thesis, University of Oxford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.236327.
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Ollerenshaw, T. J. "Synthesis and characterisation of iron-sulphur clusters of biological interest". Thesis, University of Manchester, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376138.
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Wilson, Charles Crichton. "X-ray diffraction studies of some materials of biological interest". Thesis, University of Dundee, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339873.
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Edwards, Simon D. "New routes to medium ring lactones and ethers of biological interest". Thesis, University of York, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.423774.
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Pinto, Rui Montenegro Val-do-Rio. "Photoelectron spectroscopy of nitrogen containing molecules of biological and industrial interest". Doctoral thesis, Faculdade de Ciências e Tecnologia, 2011. http://hdl.handle.net/10362/7077.
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Castrovilli, Mattea Carmen <1985>. "Elemetary processes of radiation damage in organic molecules of biological interest". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6386/1/Castrovilli_MatteaCarmen_tesi.pdf.
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It was observed in the ‘80s that the radiation damage on biological systems strongly depends on processes occurring at the microscopic level, involving the elementary constituents of biological cells. Since then, lot of attention has been paid to study elementary processes of photo- and ion-chemistry of isolated organic molecule of biological interest. This work fits in this framework and aims to study the radiation damage mechanisms induced by different types of radiations on simple halogenated biomolecules used as radiosensitizers in radiotherapy. The research is focused on the photofragmentation of halogenated pyrimidine molecules (5Br-pyrimidine, 2Br-pyrimidine and 2Cl-pyrimidine) in the VUV range and on the 12C4+ ion-impact fragmentation of the 5Br-uracil and its homogeneous and hydrated clusters.
Although halogen substituted pyrimidines have similar structure to the pyrimidine molecule, their photodissociation dynamics is quite different. These targets have been chosen with the purpose of investigating the effect of the specific halogen atom and site of halogenation on the fragmentation dynamics. Theoretical and experimental studies have highlighted that the site of halogenation and the type of halogen atom, lead either to the preferential breaking of the pyrimidinic ring or to the release of halogen/hydrogen radicals. The two processes can subsequently trigger different mechanisms of biological damage.
To understand the effect of the environment on the fragmentation dynamic of the single molecule, the ion-induced fragmentation of homogenous and hydrated clusters of 5Br-uracil have been studied and compared to similar studies on the isolated molecule.
The results show that the “protective effect” of the environment on the single molecule hold in the homogeneous clusters, but not in the hydrated clusters, where several hydrated fragments have been observed. This indicates that the presence of water molecules can inhibit some fragmentation channels and promote the keto-enol tautomerization, which is very important in the mutagenesis of the DNA.
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Castrovilli, Mattea Carmen <1985>. "Elemetary processes of radiation damage in organic molecules of biological interest". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6386/.
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It was observed in the ‘80s that the radiation damage on biological systems strongly depends on processes occurring at the microscopic level, involving the elementary constituents of biological cells. Since then, lot of attention has been paid to study elementary processes of photo- and ion-chemistry of isolated organic molecule of biological interest. This work fits in this framework and aims to study the radiation damage mechanisms induced by different types of radiations on simple halogenated biomolecules used as radiosensitizers in radiotherapy. The research is focused on the photofragmentation of halogenated pyrimidine molecules (5Br-pyrimidine, 2Br-pyrimidine and 2Cl-pyrimidine) in the VUV range and on the 12C4+ ion-impact fragmentation of the 5Br-uracil and its homogeneous and hydrated clusters.
Although halogen substituted pyrimidines have similar structure to the pyrimidine molecule, their photodissociation dynamics is quite different. These targets have been chosen with the purpose of investigating the effect of the specific halogen atom and site of halogenation on the fragmentation dynamics. Theoretical and experimental studies have highlighted that the site of halogenation and the type of halogen atom, lead either to the preferential breaking of the pyrimidinic ring or to the release of halogen/hydrogen radicals. The two processes can subsequently trigger different mechanisms of biological damage.
To understand the effect of the environment on the fragmentation dynamic of the single molecule, the ion-induced fragmentation of homogenous and hydrated clusters of 5Br-uracil have been studied and compared to similar studies on the isolated molecule.
The results show that the “protective effect” of the environment on the single molecule hold in the homogeneous clusters, but not in the hydrated clusters, where several hydrated fragments have been observed. This indicates that the presence of water molecules can inhibit some fragmentation channels and promote the keto-enol tautomerization, which is very important in the mutagenesis of the DNA.
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Meloncelli, Peter J. "The synthesis of several azasugars, glycosylated azasugars and disaccharides of biological interest". University of Western Australia. School of Biomedical, Biomolecular and Chemical Sciences, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0052.
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[Truncated abstract] The development of several carbohydrate-based pharmaceuticals has stimulated an increased interest in the field of carbohydrate chemistry. The discovery of Acarbose and invention of Miglitol, treatments for type II diabetes, as well as the influenza treatments, Relenza and Tamiflu, have been largely responsible for this increased interest. These treatments operate by the inhibition of glycoside hydrolases, a group of enzymes important in a variety of biological processes. This thesis involves the study of a group of glycoside hydrolase inhibitors known as azasugars, which are nitrogen-containing sugar mimics . . . The final chapter, Chapter 4, focuses on the testing of these disaccharides as a possible alternative carbohydrate source for pre-term infants. Initially, commercially available glycoside hydrolases were used to detect any hydrolysis of the four disaccharides, with (206) exhibiting the most promising results (to provide D-glucose and D-galactose). Detailed kinetic studies were then conducted using homogenates obtained from pig intestinal mucosa. Unfortunately, the results indicated that (206) was unsuitable as an alternative carbohydrate source for pre-term infants.
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Darsley, M. J. "Studies on the interaction of monoclonal antibodies with antigens of biological interest". Thesis, University of Oxford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.354824.
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Williams, Christina Joyce. "An ESR study of metal atoms and organometallic compounds of biological interest". Thesis, Liverpool John Moores University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.484223.
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Soussi, Jordane. "Contribution to the study of heat relaxation in nanostructures of biological interest". Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLC013/document.
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En médecine, les nanotechnologies permettent le développement de nouvelles techniques de soin comme l’hyperthermie local ou la délivrance ciblée de médicaments. Ces applications impliquent de nouveaux défis scientifiques concernant la conception de nanosystems et les propriétés de leur environnement biologique. Dans cette thèse, nous avons analysé plusieurs aspects de la relaxation thermique de tels systèmes. Nous avons mise en œuvre la fois des simulations de Dynamique Moléculaire et des mesures expérimentales de microscopie d’imagerie en temps de vie de fluorescence. Nous présentons une étude numérique du transfert thermique depuis une nanoparticule en solution aqueuse et montrons qu’attacher un polymère à sa surface permet de réduire la résistance thermique entre la particule et son environnement. Nous avons modélisé des bicouches lipidiques pour calculer leurs propriétés diélectriques et leur viscosité a été étudiée par microscopie de fluorescence. Ces expériences sont réalisées sur des membranes suspendues et des vésicules unilamellaires géantes et démontrent que la viscosité des bicouches lipidiques diminue avec la température et l’application d’une tension transmembranaire induisant un changement de structureIn medicine, nanotechnologies give the opportunity to create new care practices such as local hyperthermia and targeted drug delivery. These applications imply new scientific challenges concerning the design of nanodevices and the properties of their biological environment. In this thesis, we have analysed several aspects of heat relaxation of such systems. We have used both Molecular Dynamics numerical simulations and Fluorescence-lifetime imaging microscopy experiments. We present a study of heat transfer from a solvated nanoparticle and show that attaching a polymer on its surface reduces the thermal resistance between the particle and its aqueous environment. We have modelled lipid bilayers to compute their dielectric properties and their viscosity have been investigated by fluorescence imaging. The experiments conducted on both suspended lipid membrane and giant unilamellar vesicles show that the viscosity decreases when the temperature increases and when a transmembrane voltage is applied to inducing a structural change
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GIOFRE', SABRINA. "SYNTHESIS OF NITROGEN-CONTAINING HETEROCYCLIC SYSTEMS OF BIOLOGICAL INTEREST THROUGH DOMINO STRATEGIES". Doctoral thesis, Università degli Studi di Milano, 2020. http://hdl.handle.net/2434/701960.
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Abstract. In this thesis the synthesis of potentially biologically active heterocyclic compounds has been developed through novel catalytic methods involving C-N and C-O bond forming processes. The thesis consists of three main chapters: a) oxidative intramolecular palladium(II)-difunctionalizations of alkenes (Chapter 1); b) iodine species as a powerful tool in oxidative ring closing reaction (Chapter 2); c) intramolecular rhodium(I) allylic addition to afford α-vinyl-substituted heterocycles (Chapter 3). In Chapter 1.1 an aminoarylation process of allylic ureas has been investigated as a tool to construct 4-substituted imidazolidinones. In the presence of aryltin nucleophiles and hydrogen peroxide as an inexpensive and green oxidant, a 5-exo-regioselective procedure has been developed. On the other hand, when the homoallylic urea is used under similar conditions the seven-membered ring is obtained as a consequence of the β-elimination accountable to a Pd(II)/Pd(0) catalytic cycle. In Chapter 1.2 an intramolecular alkoxyacylation is described employing an hypervalent iodine (III) as both the acylating and oxidizing reagent. A regioselective 6-exo-trig Pd(II)-catalysed cyclisation of N-allyl aminophenol and N-allyl aminoethanol affords benzoxazine and morpholine nuclei, respectively. The synthetic utility of this new products is demonstrated through two-step transformations into purine derivatives, which are used for the treatment and prevention of cancer, and into β-aminoacids. In Chapter 2.1 it is reported the development of an intramolecular domino-type Diels Alder reaction initiated by hypervalent iodine reagents. The employment of N-allyl 2-aminophenols as substrates leads to the formation of a tricyclic system in the sole presence of I(III) species. Moreover, the insertion of various nucleophiles on the α-position of the amino group opens up the way to further unexplored functionalizations. The substrate scope is investigated varying both substituents on the aromatic ring, protective groups and nucleophiles, affording the respective products in 23-67% yields. In Chapter 2.2 a metal-free aminoiodination of O-allyl Ts-protected carbamates is described. Thus, by using hydrogen peroxide and potassium iodide in aqueous media, iodomethyl-substituted heterocycles are obtained in good yields and for selected substrates in a diastereoselective way, too. The reaction proceeds through the formation of an iodonium intermediate with the subsequent attack of the nitrogen in anti. In Chapter 3.1 an intramolecular hydroamination of Ts-protected allenyl amines is investigated. The ability of Rh(I) to catalyse a hydroamination process in a complete selective way, mostly modulating the type of ligand employed, is herein shown. Vinyl-substituted benzoxazine and benzoxazepine have been obtained in good yields and excellent enantioselectivity, as it has never been done before, by employing Josiphos J688-1 ligand and PPTS as co-catalyst. In Chapter 3.2 the results regarding the intramolecular hydroalkoxylation of allenyl alcohols are reported. N-allenyl aminoethanol, N-allenyl aminophenol, allenyl alcohols and allenyl phenols are subjects of our research. Despite the substrate diversity, the chiral ferrocelane diphosphine ligand, (R,R) Me-ferrocelane, is proven optimal for the intramolecular OH-addition to allenes. High yields and good enantioselectivity can be reached varying the Brønsted acid, employed as additive in the reaction. In conclusion, oxidative palladium(II)-catalysed alkene difunctionalizations, hypervalent iodine-promoted dearomatizing intramolecular Diels-Alder reaction, oxidative aminoiodinations and intramolecular enantioselective rhodium(I)-catalysed hydroaminations and alkoxylations of allenes are approaches described in this thesis as valuable methods for the construction of medicinally relevant heterocycles.
25
MAZZA, ALBERTO. "SUSTAINABLE CHEMISTRY FOR THE PREPARATION OF NITROGENATED POLYHETEROCYCLIC SYSTEMS OF BIOLOGICAL INTEREST". Doctoral thesis, Università degli Studi di Milano, 2017. http://hdl.handle.net/2434/480115.
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The palladium and platinum catalyzed intramolecular reactions of unsaturated systems (alkynes, alkenes and allenes) arising from commercially available o-aminophenols and o-nitroaniline have been studied. Both carbo- and hydroamination processes resulted in the formation of nitrogen- benzofused rings. The carboamination domino process led to the C–C and C–N bond formation using a wide variety of aryl- and heteroaryl halides. The regioselectivity of the cyclization step was strongly dependent on the unsaturated system and on the protecting group tethered to the nitrogen atoms, allowing the formation of five- six- and seven-membered rings.
In the second part, applications of two specific processes the Buchwald-Hartwig and Ullmann-type reactions were reported. The first process allowed the synthesis of a particular class of heteropolycyclic systems endowed with pharmacological properties as anticancer. The synthesis of the new hexacyclic system was realized starting from tryptamines and exploiting as a key step a sequential Pd-catalyzed N-arylation/acylation reaction. Having topoisomerases as biological target and the campthotecins class as benchmark, the new scaffold was decorated with substituents having different polarity and tested as Topoisomerase I inhibitors. The copper catalyzed Ullmann-type reaction was exploited to afford oxazino-indole scaffold through the intramolecular C-O bond formation, starting from N-hydroxyethyl-isatin derivatives.
26
RIVA, BENEDETTA. "investigating the functionalization of colloidal nanoparticles with small molecules of biological interest". Doctoral thesis, Università degli Studi di Milano-Bicocca, 2017. http://hdl.handle.net/10281/153282.
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1) Developement of radio-labelled SNPs for the targeted detection and treatment of Her2-positive breast cancer.Aim of this work was to develop a SNP-based system loaded with radioactive/fluorescent probes and functionalized with the half-chain of a monoclonal antibody, Trastuzumab, which specifically recognizes the human epidermal growth factor receptor 2 (Her2), overexpressed in 25-30% of human breast tumours. The silica core was covalently functionalized with FITC, further protected by a 10 nm silica shell and stabilized in saline buffer by means of differently terminated PEGs (SNP). Such nanoparticles were then conjugated with Trastuzumab half-chain (SNP-TZ). Finally, both SNP and SNP-TZ were derivatized with nitrilo-triacetic acid and labelled with 99mTc-Tricarbonyl complex, giving rise to SNP-NTA and SNP-NTA-TZ NPs. The functionalization steps were monitored both by size and z-potential measurements and the impact of each chemical moietiy on the NP behaviour in cells was assessed in prelabeling in vitro experiments comparing SNP, SNP-NTA, SNP-TZ and SNP-NTA-TZ. Targeting specificity of TZ-functionalized or TZ-free SNPs was studied in in vitro, in vivo and ex vivo experiments, both employing fluorescence and radionuclide techniques. Our results suggested that active targeting provided higher efficiency and selectivity in tumor detection compared to passive diffusion, confirming that our synthetic strategy provided stable nanoconjugates and did not affect their binding efficiency to HER2 expressing cells.2) Development of doxorubicin-loaded nonporous SNPs.
Nonporous SNPs were chosen as the starting point to produce different drug carriers, bearing the well-known anticancer drug doxorubicin. Different silica nanoformulations containing the well-known anticancer drug doxorubicin were compared: OuterDox NPs, in which doxorubicin was covalently linked on the silica surface, InnerDox NPs, in which the chemotherapeutic was covalently immobilized in the core of the same particles and DoubleDox NPs, containing the drug both externally and internally.The nanoformulations were studied in terms of carrier degradation and payload release in physiological conditions.The in vitro efficiency was also investigated.3)Development of glutathione-sensitive apoferritin NPs for the controlled delivery of luciferin.Although bioluminescence imaging has been successfully used in a variety of applications to obtain information regarding biological processes in vivo, the detection of photon emission is limited by the short half-life of luciferin (less than 30 minutes), its modest cell penetration and inhomogeneous diffusion into different tissues. In this context, we developed a glutathione-sensitive NP for stimuli-responsive release of luciferin within cancer cells. The nanoconjugate bears luciferin by means of a disulfide containing linker (Luc-linker), which, in the presence of a reducing agent, undergoes an intramolecular cyclization reaction that results in the release of free luciferin. The correct luciferin release mechanism was checked in cell-free in vitro bioluminescence tests: an abundant photon production was detected when Luc-linker was preincubated with DTT and then reacted with luciferase, while no light emission was seen without DTT pretreatment. Luc-linker was then attached to apoferritin (HFn) NP surface, exploiting the free thiol groups of cysteine residues, leading to Luc-linker@HFn NPs.After the conjugation, an HPLC method was developed for the quantification of conjugation efficiency and drug loading, requiring a preliminary separation of the linker from the hosting HFn NPs. The Luc-linker@HFn was then tested in vitro to initially elucidate the bioluminescent kinetics and compare the luminous signal to the one of nanoparticle-free luciferin.1) Developement of radio-labelled SNPs for the targeted detection and treatment of Her2-positive breast cancer.Aim of this work was to develop a SNP-based system loaded with radioactive/fluorescent probes and functionalized with the half-chain of a monoclonal antibody, Trastuzumab, which specifically recognizes the human epidermal growth factor receptor 2 (Her2), overexpressed in 25-30% of human breast tumours. The silica core was covalently functionalized with FITC, further protected by a 10 nm silica shell and stabilized in saline buffer by means of differently terminated PEGs (SNP). Such nanoparticles were then conjugated with Trastuzumab half-chain (SNP-TZ). Finally, both SNP and SNP-TZ were derivatized with nitrilo-triacetic acid and labelled with 99mTc-Tricarbonyl complex, giving rise to SNP-NTA and SNP-NTA-TZ NPs. The functionalization steps were monitored both by size and z-potential measurements and the impact of each chemical moietiy on the NP behaviour in cells was assessed in prelabeling in vitro experiments comparing SNP, SNP-NTA, SNP-TZ and SNP-NTA-TZ. Targeting specificity of TZ-functionalized or TZ-free SNPs was studied in in vitro, in vivo and ex vivo experiments, both employing fluorescence and radionuclide techniques. Our results suggested that active targeting provided higher efficiency and selectivity in tumor detection compared to passive diffusion, confirming that our synthetic strategy provided stable nanoconjugates and did not affect their binding efficiency to HER2 expressing cells.2) Development of doxorubicin-loaded nonporous SNPs. Nonporous SNPs were chosen as the starting point to produce different drug carriers, bearing the well-known anticancer drug doxorubicin. Different silica nanoformulations containing the well-known anticancer drug doxorubicin were compared: OuterDox NPs, in which doxorubicin was covalently linked on the silica surface, InnerDox NPs, in which the chemotherapeutic was covalently immobilized in the core of the same particles and DoubleDox NPs, containing the drug both externally and internally.The nanoformulations were studied in terms of carrier degradation and payload release in physiological conditions.The in vitro efficiency was also investigated.3)Development of glutathione-sensitive apoferritin NPs for the controlled delivery of luciferin.Although bioluminescence imaging has been successfully used in a variety of applications to obtain information regarding biological processes in vivo, the detection of photon emission is limited by the short half-life of luciferin (less than 30 minutes), its modest cell penetration and inhomogeneous diffusion into different tissues. In this context, we developed a glutathione-sensitive NP for stimuli-responsive release of luciferin within cancer cells. The nanoconjugate bears luciferin by means of a disulfide containing linker (Luc-linker), which, in the presence of a reducing agent, undergoes an intramolecular cyclization reaction that results in the release of free luciferin. The correct luciferin release mechanism was checked in cell-free in vitro bioluminescence tests: an abundant photon production was detected when Luc-linker was preincubated with DTT and then reacted with luciferase, while no light emission was seen without DTT pretreatment. Luc-linker was then attached to apoferritin (HFn) NP surface, exploiting the free thiol groups of cysteine residues, leading to Luc-linker@HFn NPs.After the conjugation, an HPLC method was developed for the quantification of conjugation efficiency and drug loading, requiring a preliminary separation of the linker from the hosting HFn NPs. The Luc-linker@HFn was then tested in vitro to initially elucidate the bioluminescent kinetics and compare the luminous signal to the one of nanoparticle-free luciferin.
27
Patel, Vibhuti Jitendra. "Novel mass spectrometry-based approaches for the characterisation of systems of biological interest". Thesis, University of Warwick, 2009. http://wrap.warwick.ac.uk/2787/.
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Originally established as an analytical technique in the fields of physics and chemistry, mass spectrometry has now also become an essential tool in biology. Advances in ionisation methods and novel types of instrumentation have led to the development of mass spectrometry for the analysis of a wide variety of biological samples. The work presented here describes the use mass spectrometry for the study of a number of biological systems. A new family of techniques has been developed allowing ions to be created under ambient conditions. Three of these ambient ionisation techniques, coupled to different mass analysers, were employed for the rapid screening of pharmaceutical formulations. Active ingredients were identified and subjected to collisionally induced dissociation, enabling the elucidation of potential fragmentation pathways. Drug metabolites were also successfully identified from biological samples. Inorganic mass spectrometry was employed to probe the metal centres of the enzyme, particulate methane monooxygenase, a methane-oxidising complex found in certain bacteria. This protein has been extensively studied, but questions remain regarding its catalytic mechanism, particularly the involvement of indigenous metal ions. Inductively-coupled plasma mass spectrometry experiments have indicated the presence of copper and iron within the enzyme. Protein cross-sections, obtained using ion mobility mass spectrometry, can be used to probe the conformation of molecules in the gas phase. A commercial instrument was used to investigate human hemoglobin from clinical samples. A complex assembly mechanism was deduced, resolving previous disputes in the literature, and conformational differences were observed between healthy and sickle molecules. The field of proteomics is rapidly evolving; as described, techniques are constantly being developed and improved to deal with the enormous complexity that proteomes present. Three proteomics approaches were used to study a recently identified bacterium under two growth conditions. Differences in protein expression were observed and correlated to relevant biological pathways.
28
ONDAR, GRISSET TOMASA FAGET. "SYNTHESIS E CHARACTERIZATION OF THE COMPLEXES WITH SULFURED AMINO ACIDS OF BIOLOGICAL INTEREST". PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2005. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=7654@1.
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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICONo presente trabalho realizou-se a síntese e caracterização de complexos de zinco e cádmio no estado sólido. Foram sintetizados complexos binários e ternários envolvendo os aminoácidos: glicina,ácido aspártico, metionina, cisteína e o tripeptídeo glutationa, os quais formam parte de diversas proteínas que atuam no sistema nervoso central. Embora estudos em solução envolvendo a formação de complexos entre estes metais e aminoácidos tenham sido realizados, há o reconhecimento de que, em diversas doenças neurodegenerativas, ocorre a precipitação de aglomerados sólidos provenientes de proteínas. Isto cria a necessidade de se estudar estes sistemas no estado sólido. Assim, no presente trabalho, foram desenvolvidas rotas de sínteses, que permitem a obtenção destes complexos em condições próximas ao meio biológico. Modelos simples foram sintetizados e caracterizados pelas técnicas de Espectroscopía Infravermelha, Espectroscopía Raman, Análise Termogravimétrica, Análise Elementar e Absorção Atômica. Foi selecionado um composto com cisteína para realizar um estudo espectroscópico detalhado, utilizando cálculos de mecânica quântica, permitindo a atribuição das bandas nos espectros infravermelho e Raman, identificando-se as bandas M-S e M-N de difícil caracterização. A conclusão deste trabalho mostrou que a grande afinidade destes metais (zinco e cádmio) pelo enxofre permite a realização das sínteses mesmo em meio ácido, observando-se uma redução na tendência de precipitação ao passar dos compostos binários, a ternários e à glutationa. Tripeptídeos como a glutationa facilitam a formação de soluções coloidais estáveis, acontecendo a formação de fases sólidas após um grande período de tempo. Assim, um aumento no potencial zeta, permite a formação de uma fase sólida em poucas horas.
In the present work the synthesis and characterization of solid state zinc and cadmium complexes with sulfured amino acids were performed. Binary and ternary complexes, involving glycine, aspartic acid, methionine, cysteine and glutathione tripeptide were synthetized. These compounds form several proteins that act in the central nervous system. Although studies on the formation of complexes between these metals and amino acids in solution, were realized it is a relevant and interesting topic the fact that in several neuro-degenerative illness occur the precipitation of solid agglomerates from proteins. This shows the necessity of study these systems in the solid state. Thus, in the present work, different routes of synthesis were developed in similar conditions to the biological medium. Simple models were synthesized and characterized by Infrared spectroscopy, Raman spectroscopy, Thermogravimetric analysis, Elemental analysis and Atomic absorption spectrometry. These complexes allow the comprehension of the complex molecules which form these systems. A compound with cysteine was chosen to perform a detailed spectroscopic study using quantum mechanical calculation which permitted identification of the the infrared and Raman spectra bands, M-S and M-N which are very difficult to characterize. The conclusion of this work showed that the big affinity of these metals (zinc and cadmium) for sulfur allowed the synthesis in acid medium. It was observed a reduction in the tendency of precipitation when passing binary from binary to ternary compounds and then to glutathione. Tripeptides like glutathione facilitated the formation of stable colloidal solutions, and the formation of solid phases only occurred after a considerable period of time, so, an increase in the zeta potential allows the formation of a solid phase in few hours.
29
Long, Joanna R. (Joanna Ruth). "Solid state NMR studies of structure and dynamics in systems of biological interest". Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/43308.
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30
Pelà, Michela. "Enantioselective approaches and domino sequences for the synthesis of compounds of biological interest". Paris 6, 2011. http://www.theses.fr/2011PA066104.
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(R/S)-SHA-6821 est le premier antagoniste non peptidique sélectif au récepteur NPSR. Les excellentes propriétés pharmacologiques de ce ligand nous ont conduit vers la synthèse énantiosélective, la purification et la caractérisation de deux composés optiquement purs afin d'évaluer séparément leur activité pharmacologique. (R)-SHA 68 est le seul énantiomère capable d'antagoniser l'activité du ligand endogène du récepteur NPSR. Grace une collaboration avec l’équipe du Prof. Giovanni Poli, au sein de laquelle j’ai pu effectuer un stage de neuf mois (doctorat en co-tutelle), il nous est paru intéressant appliquer réactions catalysées au palladium, à partir de précurseurs alléniques, à la synthèse d’un nouvel analogue azoté de la (-)-Stéganacine. La réaction clef de notre stratégie synthétique est la séquence domino « carbopalladation d’allène / alkylation allylique » qui a été optimisée dans les laboratoires du Prof. Poli. 41 Cette réaction nous a permis d'obtenir le γ-lactame désiré avec un rendement de 74%.
31
PELA', Michela. "Enantioselective Approaches and Domino Sequences for the Synthesis of Compounds of Biological Interest". Doctoral thesis, Università degli studi di Ferrara, 2011. http://hdl.handle.net/11392/2388758.
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Neuropeptide S (NPS) is the endogenous ligand of the previously orphan G-protein
coupled receptor, recently named NPSR.12 NPS is a small peptide of 20 amino acids and
rapresents the endogenous ligand of NPSR. In cells expressing the recombinant NPSR
receptor, NPS selectively binds and activates its receptor, producing intracellular
calcium mobilization and an increase of cAMP levels. The NPS-NPSR receptor system
regulates important biological functions such as sleep/waking, locomotion, anxiety and
food intake.
(R/S) SHA-68 21 is the first non-peptide antagonist of NPSR receptor; actually only a
class of molecules able to interact with NPSR are reported in the literature and they are
the same oxazol-piperazine structure.
Initially, in order to confirm the published data, we decided to synthesize SHA 68 in
racemic form following the Okamura’s methodology21.
The high selectivity of (R/S)-SHA 68 for NPSR and its good antagonist activity
prompted us to synthesize the enantiomers of this non-peptide compound, starting from
cheap commercially available reagents as chiral auxiliary.
In order to define the conformation of the piperazine ring in this two enantiomers we
performed a series of NMR experiments leading to define a chair conformation where
the substituent in C9 was placed in equatorial position.
To know the absolute configuration of the new chiral centre X ray analysis was
performed on suitable crystals that show us the R configuration of the new stereogenic
centre.
From a pharmacological point of view (R)-SHA 68 was demonstrated to be the
antagonist of the receptor of the Neuropeptide S.
This new class of non-peptide NPSR antagonists provides additional tools for in vitro
and in vivo studies required to elucidate the NPSR conformation, adding new
informations to well know NPS-NPSR system.
In the frame of the synthesis of biological active chiral compounds I have spend nine
months at the Pierre et Marie Curie University in Paris under the supervision of
Professor Giovanni Poli, focusing the attention on the synthesis of natural product (-)-
Steganacin. This stage allowed me to view a different approach for the selective
generation of new structures using a palladium catalysed domino reactions instead of
the use of chiral auxiliaries used for the synthesis of (R) and (S)-SHA 68.
Steganacin was isolated from a plant of South Africa, Steganotaenia araliacea.31 The
interest of chemists for the (-)-Steganacin was initially motivated by its antitumor
activity; 34 it is for this reason that in literature we found different total syntheses of this
molecule.
From a structural point of view the (-)-Steganacine presents a γ-lactonic skeleton
condensed to an eight membered ring, a biarylic portion and three contiguous
stereogenic centers with a relative stereochemistry trans, trans.
Aim of this project is the synthesis of an aza-analogue of Steganacine in which the
lactone structure is replaced by a γ-lactam moiety.
The synthetic process starts from a commercially available propargyl alcohol to afford
in seven steps the desired cyclization precursor in 19 % yield.
The key step of our project was previously studied in the laboratories of Prof. Giovanni
Poli and reported in literature by Kammerer et al. in 2009.41 This is an original regioand
stereoselective synthesis of aryl substituted pyrrolidones by a phosphine-free Pdcatalyzed
allene carbopalladation/allylic alkylation sequence. This reaction allowed us
to obtain the key intermediate in 74% yield.
After benzylation of this key intermediate, several strategies to remove the
methoxycarbonyl group were tested, the best solution being hydrolysis in ethylene
glycol at high temperatures. The next study will focus on the non-phenolic oxidative
coupling between the two aromatic moieties to formed an eight membered ring.
Then, an oxidative cleavage of the double bond followed by a diastereoselective
reduction of the resulting ketone and final alcohol acetylation should afford the desired
(-)-Steganacin aza-analogue.
32
Silva, Rita de C?ssia Barreto da. "Prospec??o de genes de interesse biotecnol?gico : uma abordagem metagen?mica". Universidade Federal do Rio Grande do Norte, 2009. http://repositorio.ufrn.br:8080/jspui/handle/123456789/16763.
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Previous issue date: 2009-02-27Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico
The total number of prokaryotic cells on Earth has been estimated at 4 to 6x1030 and only about 1% of microorganisms present in the environment can be cultivated by standard techniques of cultivation and plating. Therefore, it is a huge biological and genetic pool that can be exploited, for the identification and characterization of genes with biotechnological potential. Within this perspective, the metagenomics approach was applied in this work. Functional screening methods were performed aiming to identify new genes related to DNA repair and / or oxidative stress resistance, hydrocarbon degradation and hydrolytic activities (lipase, amylase and protease). Metagenomic libraries were built utilizing DNA extracted from soil samples collected in Jo?o C?mara RN. The libraries were analyzed functionally using specific substrate containing solid medium (hydrolytic activity), supplemented with H2O2 (DNA repair and / or resistance to oxidative stress) and liquid medium supplemented with light Arabian oil (activity, degradation of hydrocarbons). After confirmation of activity and exclusion of false-positive results, 49 clones were obtained, being 2 positive for amylase activity, 22 resistant to oxidative stress generated by H2O2 and 25 clones active for hydrocarbons degradation. Analysis of the sequences showed hypothetical proteins, dienelactona hydrolase, DNA polymerase, acetyltransferase, phosphotransferase, methyltransferase, endonucleases, among other proteins. The sequence data obtained matched with the functions tested, highlighting the success of metagenomics approaches combined with functional screening methods, leading to very promising results
O n?mero total de c?lulas procari?ticas na Terra tem sido estimado em 4 a 6x1030 sendo que apenas cerca de 1% dos microrganismos presentes no meio ambiente pode ser cultivado, atrav?s de t?cnicas padr?o de cultivo e plaqueamento, se apresentando, portanto, como um enorme pool biol?gico e gen?tico que pode ser explorado, visando a identifica??o e a caracteriza??o de genes com potencial biotecnol?gico. Dentro desta perspectiva, a abordagem metagen?mica foi aplicada neste trabalho a partir de metodologias de sele??o funcional visando ? identifica??o de novos genes relacionados ao reparo de DNA e/ou resist?ncia a estresse oxidativo, genes relacionados com atividade de degrada??o de hidrocarbonetos, e atividade hidrol?tica (lipase, amilase e protease). Com esse objetivo, uma biblioteca metagen?mica, constru?da a partir de amostras de solo coletadas no munic?pio de Jo?o C?mara RN, foi analisada funcionalmente utilizando meios s?lidos contendo substratos espec?ficos (atividade hidrol?tica), suplementados com H2O2 (reparo de DNA e/ou resist?ncia a estresse oxidativo) e meio liquido suplementado com ?leo ?rabe leve (atividade de degrada??o de hidrocarbonetos). Ap?s confirma??o da atividade e exclus?o de falsos-positivos foram obtidos 49 clones, sendo 2 positivos para atividade amilase, 22 resistentes ao estresse oxidativo gerado por H2O2 e 25 com atividade de degrada??o de hidrocarbonetos, cuja an?lise das seq??ncias revelou,al?m de prote?nas hipot?ticas, dienolactona hidrolase, DNA polimerases, acetiltransferase, fosfotransferase, metiltransferase, endonucleases entre outras, cuja coer?ncia com as fun??es ensaiadas, ressalta o sucesso da abordagem metagen?mica aliada a metodologias funcionais e, os resultados obtidos bastante promissores. PALAVRAS CHAVE: Metagenoma, Biotecnologia
33
Carlin, Graham Richard. "The fabrication of biodegradable nanospheres from novel hydroxyalkanoates for the delivery of actives of pharmaceutical and agricultural interest". Thesis, Aston University, 2001. http://publications.aston.ac.uk/11010/.
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This work describes the fabrication of nanospheres from a range of novel polyhydroxyalkanoates supplied by Monsanto, St Louis, Missouri, USA for the delivery of selected actives of both pharmaceutical and agricultural interest. Initial evaluation of established microsphere and nanosphere fabrication techniques resulted in the adoption and optimisation of a double sonication solvent evaporation method involving the synperonic surfactant F68. Nanospheres could be consistently generated with this method. Studies on the incorporation and release of the surrogate protein Bovine Serum Albumin V demonstrated that BSA could be loaded with between 10-40% w/w BSA without nanosphere destabilisation. BSA release from nanospheres into Hanks Balanced Salts Solution, pH 7.4, could be monitored for up to 28 days at 37°C. The incorporation and release of the Monsanto actives - the insecticide Admire® ({ 1-[(6-chloro-3-pyridinyl)methyIJ-N-nitro-2-imidazolidinimine}) and the plant growth hormone potassium salt Gibberellic acid (GA3K) from physico-chemically characterised polymer nanospheres was monitored for up to 37 days and 28 days respectively, at both 4°C and 23°C. Release data was subsequently fitted to established kinetic models to elaborate the possible mechanisms of release of actives from the nanospheres. The exposure of unloaded nanospheres to a range of physiological media and rural rainwater has been used to investigate the role polymer biodegradation by enzymatic and chemical means might play in the in vivo release of actives and agricultural applications. The potential environmental biodegradation of Monsanto polymers has been investigated using a composting study (International Standard ISO/FDIS 14855) in which the ultimate aerobic biodegradation of the polymers has been monitored by the analysis of evolved carbon dioxide. These studies demonstrated the potential of the polymers for use in the environment, for example as a pesticide delivery system.
34
Marchese, Vittoria. "Acquisizione di materiale biologico e banche dati forensi: un equo contemperamento tra interessi potenzialmenti confliggenti". Doctoral thesis, Università degli studi di Padova, 2017. http://hdl.handle.net/11577/3421930.
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In June 2009, the Italian Parliament passed Law n. 85.
This law regulates the institution of the Italian National Forensic DNA Database and introduces modification articles of the Code of Penal Procedure in relation to the technical assessments that can affect personal freedom involved in biological sampling and collection of DNA profiles.
Italian law No. 85/2009 ratifies the Prüm Treaty which is an agreement of seven EU Member States regarding cooperation in justice and home affairs and establishing the highest possible standard of cooperation in exchange of information, particularly in combating terrorism, crossborder
crime and illegal migration.
Even though DNA databases are a great value for investigation and society, it may be troublesome to solve the balance between the public interest in crime control and individual rights such as personal freedom, dignity and privacy.
The critical analysis of the Italian regulation testifies that a fair balance between individual rights and social security is extremely hard to fulfill.La legge 30 giugno 2009, n. 85 costituisce il primo intervento normativo organico sulla acquisizione e sul trattamento dell’informazione genetica a fini forensi. Con la legge n. 85 del 2009, il presidente della Repubblica è autorizzato ad aderire al Trattato di Prüm sul rafforzamento della cooperazione transfrontaliera. Uno degli strumenti attuativi privilegiati per l’ottemperanza degli obblighi discendenti dall’adesione al Trattato è rappresentato dallo scambio di informazioni genetiche, sul presupposto che le parti contraenti si impegnano «a creare e a gestire degli schedari nazionali di analisi del DNA al fine di perseguire le violazioni penali». La riforma prevede, a tale fine, l’istituzione della Banca dati nazionale del DNA e del relativo Laboratorio centrale per la Banca dati nazionale. Il legislatore del 2009 interviene, poi, a colmare la persistente lacuna sull’esecuzione coattiva dei prelievi biologici, scaturita dalla declaratoria di illegittimità dell’articolo 224 c.p.p., di cui alla sentenza costituzionale n. 238 del 1996. In proposito, la legge n. 85 introduce norme che si propongono di affrontare sistematicamente la dimensione probatoria degli accertamenti corporali coattivi e recano consistenti modifiche al codice di procedure penale. La riforma del 2009 è, nel complesso, apprezzabile per aver riportato nel campo dei principi fondamentali del diritto processuale penale una materia rimasta troppo a lungo priva di regolamentazione nel nostro Paese. L’obiettivo del presente lavoro è la definizione di un modello di disciplina in materia di indagine genetica, che soddisfi le istanze di salvaguardia sottese a ciascuna delle situazioni giuridiche soggettive coinvolte e tenga debito conto degli aspetti applicativi. Si tratta di una proposta de iure condendo con cui è destinata a confrontarsi la disciplina vigente nel nostro Paese.
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Barbany, Puig Montserrat. "Three Dimensional Simulitary of Molecules with biological interest on the basis of molecular interaction potentials". Doctoral thesis, Universitat Pompeu Fabra, 2006. http://hdl.handle.net/10803/7146.
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Una de les àrees més prometedores en recerca biomèdica i farmacèutica és el disseny molecular computacional, que intenta establir relacions entre propietats físico-químiques i activitat biològica. L'èxit d'aquestes tècniques depen críticament de la qualitat de la descripció molecular. En aquest sentit, metodologies basades en potencials d'interacció molecular (MIP) són eines útils per la comparació de compostos que presenten comportaments biològics semblants.
Aquest projecte desenvolupa eines per comparar molècules basades en la caracterització de llurs MIPs. El programa de similaritat molecular MIPsim ha estat desenvolupat i aplicat a diferents problemes biològics.
Aquesta tesi consisteix en quatre estudis científics que mostren l'ús del MIPSim en aliniament molecular, catalisi enzimàtica, en acoratge de molècules dins el lligand i en estudis 3D-QSAR.
One of the most promising areas in biomedical and pharmaceutical research is computer assisted molecular design, which tries to stablish relationships between physicochemical properties and biological activity.
The success of these techniques depends critically on the quality of the molecular description. In this sense, methodologies based on molecular interaction potentials (MIP) are useful tools for the comparison of compounds displaying related biological behaviours.
This project aims to develop tools to compare 'molecules based on the characterization 'of their MIPs. To this end, the molecular similarity program MIPSim has been further developed and applied to different biological problems.
This thesis consists on four scientific studies showing the use of MIPSim for molecular alignment, enzymatic catalysis, ligand-protein docking and 3D-QSAR analyses.
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Alfazil, Abdulkareem Abdulwahab. "Stability of drugs and pesticides of forensic toxicological interest and their metabolites in biological samples". Thesis, University of Glasgow, 2009. http://theses.gla.ac.uk/1309/.
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Loss of analyte from biological samples during the post-mortem interval or during storage has potentially serious implications in forensic toxicology and represents a challenge for the forensic toxicologist, especially in the interpretation of case results. The initial aim of the studies in this thesis was to evaluate the stability of some important drugs and compounds in blood under different storage conditions in order to optimize the preservation of these compounds. A second aim was to evaluate a new method of stabilizing these compounds in blood by storing them as dried blood spots on filter paper. The third aim was to investigate methods by which corrections could be made for analyte losses based on quantification of their degradation products, which would serve as markers of the former presence of the compounds even if they were no longer detectable. The background to toxicology and its classification systems is reviewed along with the most common areas of application, including forensic toxicology. Details are given of the most commonly-used matrices and of current problems facing forensic toxicologists, particularly the problem of analyte instability. The literature concerning stability of drugs and pesticides in biological samples are reviewed and discussed as well as methods applied to enhance and stabilize analytes for long storage periods. Background is provided on methodologies used in the work reported in this thesis, including extraction techniques and instrumental analysis by LC-MS/MS and GC/MS. Also, because of its importance in forensic toxicology at present validation procedures and requirements are also discussed. An initial study was made of drug stability during storage in blood samples for 1 year under conventional laboratory conditions using selected drugs from the benzodiazepine group, alprazolam, lorazepam, oxazepam and estazolam. Blank blood containing these drugs at low and high concentrations was stored in tubes at -20° C, 4°C and room temperature. Half of the tubes contained fluoride-oxalate preservative. Blood samples were analysed on the first (day zero), second and fourth days, and after one week, two weeks, one month, two months, three months, six months and one year using a method which was developed and validated for this study based on solid phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Alprazolam and estazolam were stable at -20° C and 4° C, but decreased by almost 10% at room temperature (RT) at both concentrations. Lorazepam and oxazepam were stable at 20°C but were poorly stable at 4° C and decreased by 100% at RT by the end of the 1 year period. Sodium fluoride stabilised the drugs by approximately 13% compared to unpreserved samples. The long-term stability of alprazolam and estazolam is attributed to the presence of the trizolo ring in their structures which makes the compounds more resistant to hydrolysis, the most prominent degradation reaction affecting benzodiazepines. A similar study was performed on the stability of morphine-3- and 6-glucuronide and codeine-6-glucuronide in blood and urine under the same storage conditions. These compounds were stable at -20° C, losing less than 7% but losses were higher at 4° C, up to 18% in blood and 28% in urine, and at room temperature up to 54% in blood and 78% in urine after 1 year. Sodium fluoride did not have a significant effect (<10% increase in stability). An investigation was carried out on stabilisation of hydrolytically-labile benzodiazepines and cocaine in blood during storage as dried blood spots (DBS) on filter paper. An analytical method was developed and validated for this study based on SPE and LC-MS/MS analysis. The drugs selected were flunitrazepam, temazepam, oxazepam, lorazepam, nitrazepam, diazepam and cocaine. Blood spots (100 µl blood) on Guthrie card 903 containing the drugs at 1000ng/ml were dried overnight at RT. Spots were cut out and extracted with buffer (pH 6), which was analysed with the validated method. DBS were stored in duplicate at RT, 4°C and -20°C for up to one year. Degradation of the drugs in DBS in all storage conditions was less than for the corresponding liquid blood samples stored under similar conditions. More than 80% of each analyte could be recovered from DBS after one month while 15 % cocaine and 74 % of the benzodiazepines were recovered after 1 year under all conditions. The degradation of diazepam, temazepam, chlorodiazepoxide and oxazepam by hydrolysis was studied over a 1 month period under conditions designed to accelerate the reaction (80 °C, pH 2 and 12) and the hydrolysis products 2-methylamino 5-chlorobenzophenone (MACB) and 2-amino 5-chlorobenzophenone (ACB) were analysed by a method based on SPE and LC-MS/MS which was developed and validated for this study. MACB and ACB in whole blood and urine were evaluated as indicators of the original drug concentrations. Blank blood and urine containing these compounds at 1000 ng/ml stored at high temperature (80°C) and under acidic (pH 2) and basic (pH 12) conditions at room temperature for one month. The samples were analyzed in duplicate at days 1, 2, 4, 7, 14 and 30. MACB and ACB were the main hydrolysis products and their concentrations increased as degradation of the drugs proceeded. They could be detected when the starting materials had completely disappeared. However, MACB and ACB were found to be further degraded under some of the conditions used and a further study was made of the conversion of MACB to ACB. It was concluded that the drugs studied were more sensitive to alkaline pH than to acidic pH or high temperature and that MACB and ACB can be used to confirm the original presence of these drugs in samples, especially when they have decomposed due to poor or prolonged storage conditions. A final study was made of organophosphates (OPs) and their dialkylphosphate (DAP) hydrolysis products. A new method was developed and validated for analysis of OPs and DAPs in blood samples based on SPE and GCMS after derivatization with N-tert-butyldimethylsilyl-N-methyltrifluroacetamide. The influence of sodium fluoride preservative and storage as DBS on filter paper on the stability of OPs in blood was assessed over a 3 day period at RT. With preservative, DAPs concentrations increased as degradation of the OPs proceeded and they could be detected when the parent compounds had completely disappeared. OPs in DBS showed good stability in comparison to liquid blood samples containing NAF and the parent compounds were detected at the end of the observation period. It was concluded that careful attention should be given to the storage of samples to avoid loss of analyte and erroneous interpretation of results. DBS could be an effective and inexpensive way of increasing analyte retention but routine use of preservatives without evaluation of their effects is discouraged, as these may accelerate loss of analyte.
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ALMEIDA, BARBARA LUCIA DE. "SYNTHESIS AND CHARACTERIZATION OF POLYAMINES, ADENOSINE 5`TRIPHOSPHATE, PHOSPHOCREATINE COMPOUNDS AND SOME BIOLOGICAL INTEREST METALS". PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2008. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=12171@1.
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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOEste trabalho descreve a síntese e caracterização de compostos de Cu(II), Co(II) e Cd(II). As técnicas de caracterização utilizadas foram análise elementar, termogravimetria, UV-vis, espectroscopia de infravermelho, RMN (para complexos de Cd(II)), EPR (para complexos de cobre (II)) e difração de raio X, quando obtidos cristais. A primeira parte do trabalho foi a síntese de um novo complexo: [Cu(PCr)(H2O)], e os resultados sugerem que a PCr age como um ligante tridentado (o átomo de nitrogênio do grupo guanidino e os átomos de oxigênio dos grupos fosfato e carboxilato como sendo os átomos doadores). A quarta posição na esfera de coordenação é ocupada por uma molécula de água. Estes resultados foram confirmados através de cálculos computacionais (DFT/B3LYP:6- 311G procedimento teórico) e mostram que o cobre(II) está tetracoordenado com uma geometria quadrática plana. A segunda parte deste trabalho foi a síntese de quatro novos complexos do tipo [Cu(ATP)(poliamina)], contendo como ligante as poliaminas (PA): etilenodiamina, 1,3- diaminopropano, espermidina, espermina e o ATP. Os valores dos parâmetros paralelos de EPR para os complexos mostram que o íon cobre(II) está complexado através dos oxigênios dos fosfatos do ATP. Os dados da TG indicam que nos omplexos estão presentes moléculas de água de hidratação. A parte final deste trabalho foi o estudo das interações dos sistemas entre as poliaminas e os tetraclorometalatos. Quatorze novos compostos de Cu(II), Co(II) e Cd(II) de estequiometria [MCl4(poliamina)] contendo, além das poliaminas já citadas, a poliamina putrescina foram preparados. Um complexo de Co(II) com a estequiometria [CoCl2(H2O)4]Put.2HCl, foi preparado e formou cristais.
This work describes the synthesis and characterization of Cu (II), Co(II) e Cd(II) compounds. The characterization was performed by means of elemental and thermogravimetric analysis, UV-vis, IR, RMN (for Cd(II) compounds), EPR (for Cu(II) compounds) and X-ray diffractometry (for crystals). The first part of this work was the synthesis of one new complex : [Cu(PCr)(H2O)] and the results suggest that PCr is acting as a tridentate ligand (the nitrogen atom of the guanidine group and the oxygen atom of the phosphate group and the carboxylate group being the donor atoms). The fourth position is occupied by a water molecule. These results were confirmed through computational calculations (DFT/B3LYP:6-311G theoretical procedure) and show that Cu(II) is tetracoordinated and arranged in a tetrahedric geometry. The second part of the study was the synthesis and characterization of four new complexes of the type [Cu(ATP)(polyamine)] containing as ligands the polyamines (PA): ethylenediamine, 1,3-diaminepropane, spermidine or spermine and ATP. The EPR parallel parameters values for the complexes show that Cu(II) is complexed through the oxygen atoms from the phosphates groups of ATP. TG data indicate that each complex has the presence of one water molecule of hydration. The final part of this work was the study of the interactions occurring in systems between tetrachlorometalates and the polyamines. Fourteen new compounds of Cu(II), Co(II) and Cd(II) of stoichiometry [MCl4(polyamine)] were prepared, containing all the polyamines cited before plus putrescine were prepared. One complex of Co(II) with the stoichiometry [CoCl2(H2O)4] Put.2HCl, has formed single crystals.
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REIS, ALINE CRUZ DE MORAES. "SYTHESIS AND CHARACTERIZATION OF COPPER (II) AND ZINC (II) COMPLEXES WITH DIPEPTIDES OF BIOLOGICAL INTEREST". PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2010. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=16186@1.
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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFUNDAÇÃO DE APOIO À PESQUISA DO ESTADO DO RIO DE JANEIRO
Este trabalho descreve a síntese e caracterização de quatro complexos de cobre (II) e quatro complexos de zinco (II), com dipeptídeos, no estado sólido. Os dipeptídeos envolvidos foram: glicil-glicina, glicil-valina, metionil-metionina, metionil-glicina e cisteinil-glicina, cujos aminoácidos fazem parte de algumas proteínas envolvidas em processos de neurodegeneração, mais especificamente na doença de Alzheimer. Embora os mecanismos que desencadeiam esta patologia não estejam ainda totalmente esclarecidos, sabe-se que os íons metálicos, como o cobre (II) e o zinco (II), interagem com o peptídeo beta-amilóide. Acredita-se que tais interações favoreçam a formação de agregados protéicos sólidos deste peptídeo, observados nos cérebros de pacientes com essa doença. Dessa forma, a obtenção e o estudo de modelos simples no estado sólido, sintetizados em condições próximas ao meio biológico, podem permitir uma melhor compreensão de possíveis interações de tais metais neste sítio protéico. Os compostos obtidos foram caracterizados utilizando as seguintes técnicas: análise elementar, absorção atômica, espectroscopia de infravermelho, espectroscopia Raman, espectroscopia de ultravioleta-visível, termogravimetria, RPE (para os complexos de cobre) e condutivimetria. Para os complexos de zinco, foram realizados cálculos teóricos mecânico-quânticos para obtenção de parâmetros geométricos e espectros de infravermelho. A análise dos compostos obtidos mostrou que os complexos de cobre e zinco com os dipeptídeos estão coordenados por átomos de oxigênio e nitrogênio. Nos complexos de peptídeos contendo enxofre, a coordenação também ocorre pelo átomo de enxofre (cobre com metionil-metionina e metionil-glicina e zinco com cisteinil-glicina). Os compostos obtidos para ambos os metais na proporção metal-ligante (1:1) mostram comportamento diferente dos estudos em solução e aqueles obtidos na proporção metal-ligante (1:2) mostram comportamento similar a complexos de metais com aminoácidos.
This work describes the synthesis and characterization of copper (II) and zinc (II) complexes, with dipeptides in solid state. The dipeptides involved were: glycyl-glycine, glycyl-valine, methionyl-methionine, methionyl-glycine and cysteinyl-glycine, whose aminoacids take part in some proteins involved in neurodegeneration processes, more specifically in Alzheimer’s disease. Although the mechanisms that trigger this pathology are still not totally clear, it is known that metallic ions, such as copper (II) and zinc (II) interact with the beta-amyloid peptide. It seems that such interactions favor the formation of solid proteic aggregates of this peptide, observed in the brains of patients with Alzheimer’s disease. Thus, the obtaining and study of simple models in the solid state, synthesized in similar conditions to the biological medium, may allow a better understanding of the possible interactions of such metals in this proteic site. The compounds obtained were characterized using the following techniques: elemental analysis, atomic absorption, infrared spectroscopy, Raman spectroscopy, ultraviolet-visible spectroscopy, thermogravimetry, EPR (for the copper complexes) and conductivimetry. For the zinc complexes, quantum-mechanical theoretical calculations were performed to obtain geometrical parameters and infrared spectra. The analysis of the compounds showed that the copper and zinc complexes with dipeptides are coordinated through oxygen and nitrogen atoms. In complexes of dipeptides containing sulfur, coordination trough the sulfur atom occurs too (copper with methionyl-methionine and methionyl-glycine and zinc with cysteinyl-glycine). The compounds obtained for both metals at the metal-ligand ratio (1:1) behave differently from those studied in solution e those obtained in the metal-ligand ratio (1:2) show similar behavior of metal complexes with aminoacids.
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CHINAGLIA, Nicola. "Design, synthesis and biological evaluation of novel nucleoside and oligonucleotide conjugates of bio-medical interest". Doctoral thesis, Università degli studi di Ferrara, 2019. http://hdl.handle.net/11392/2487947.
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Bioconjugation is the process of linking or connecting a biological molecule with another moiety. This moiety may include another biomolecule: in this case a hybrid is formed, in which the properties of the parent molecules are integrated, yielding a single entity with two different functions. With the aim to discover new nucleoside-based compounds of bio-medical interest, we consider bioconjugation as a powerful approach.
In light of the well-known therapeutic potential of nucleosides as antitumorals and antivirals, in the first work reported in this thesis a conjugate between 2'-deoxyadenosine and a molecule called "photocage" was synthesized: the latter is in fact able to release under irradiation nitric oxide, whose activity in various bioregulatory systems has been proven in recent studies. Furthermore, two other bioconjugates were synthesized between the same photocage and the ursodeoxycholic and chenodeoxycholic bile acids, using click chemistry reactions. The novel bioconjugates were subjected to cytotoxicity tests and subsequently to photobiological studies that confirmed the combination of chemo- and phototherapeutic effects.
In the second work the amphiphilic nature of bile acids was considered, which makes them suitable carriers for poorly lipophilic molecules, as in our case the nucleosides, increasing their cellular uptake. Therefore, new bioconjugates were made using CuAAC reactions between 2'-deoxyadenosine, 2'-deoxyguanosine, 2'-deoxyuridine, adenosine and guanosine alkyne derivatives, and azide derivatives of cheno-, urso-, nor-cheno-, nor-urso- and taurourso-deoxycholic acids. Biological and structure-activity relationship tests on new hybrids have shown that cytoselectivity is mainly driven by the nature of the bile acid and can be fine-tuned by the nature of the nucleoside.
The ability of bile acids as carrier molecules has also been exploited in the third work: here the ursodeoxycholic acid and other lipophilic molecules have been conjugated to an antisense oligonucleotide able to associate with the exon of the human dystrophin gene which is more frequently responsible for Duchenne Muscular Dystrophy, in order to improve exon skipping approach. For the synthesis of the oligonucleotide the classic phosphoramidite chemistry in solid phase was used, using the oligosyntesizer "Äkta Oligopilot Plus". By inserting suitable amino linkers to the 3'- and 5'-ends of the oligonucleotide and by the activation of the carboxylic groups present on the lipophilic molecules as N-succinimide esters, it was possible to carry out the bioconjugation by means of amide bonds. Following the tests performed in vitro and in vivo, an increase in the amount of dystrophin in the muscle cells treated with the oligonucleotide conjugated with ursodeoxycholic acid has emerged compared to those treated with the unconjugated oligonucleotide.
In the last work of this thesis, bioconjugation was used to synthesize biomimetic compounds of UDP-GlcNAc, a natural substrate of glycosyltransferases, in which the β-phosphate was replaced by an alkyl chain or a triazole ring. These new compounds were then studied as glycosyltransferase inhibitors, as the dysregulation of these enzymes is related to various diseases, including cancer and neurodegenerative syndromes. Uridine monophosphate was conjugated with glucose, N-acetylglucosamine or a pyrrolidine ring substituted in various ways. Enzymatic, spectroscopic and computational studies were in agreement, highlighting how the absence of β-phosphate should be adequately counterbalanced in glycomimetics to have inhibition at micromolar concentrations.La bioconiugazione è il processo di collegamento di una molecola biologica con un'altra entità chimica. Quest’ultima può includere un'altra biomolecola: in questo caso si forma un ibrido, nel quale le proprietà delle molecole genitrici si integrano, producendo una singola entità con due differenti funzioni. Allo scopo di scoprire nuovi composti di interesse bio-medico a base di nucleosidi, abbiamo considerato la bioconiugazione una valida strategia. Alla luce del ben noto potenziale terapeutico dei nucleosidi come antitumorali e antivirali, nel primo lavoro riportato in questa tesi è stato sintetizzato un coniugato tra 2'-deossiadenosina e una molecola definita “fotogabbia”: quest’ultima è infatti in grado di rilasciare sotto stimolo luminoso ossido nitrico, la cui attività in vari sistemi bioregolatori è stata provata in recenti studi. Sono stati inoltre sintetizzati altri due bioconiugati tra la stessa fotogabbia e gli acidi biliari ursodesossicolico e chenodesossicolico, utilizzando reazioni di click chemistry. I nuovi bioconiugati sono stati sottoposti a test di citotossicità e successivamente a studi fotobiologici che ne hanno confermato la combinazione di effetti chemo- e fototerapeutici. Nel secondo lavoro è stata considerata la natura anfifilica degli acidi biliari, che li rende adeguati carrier per molecole scarsamente lipofiliche, come nel nostro caso i nucleosidi, aumentandone l’uptake cellulare. Sono quindi stati realizzati nuovi bioconiugati utilizzando reazioni CuAAC tra derivati alchinici di 2'-deossiadenosina, 2'-deossiguanosina, 2'-deossiuridina, adenosina e guanosina, e derivati azidici degli acidi cheno-, urso-, nor-cheno-, nor-urso- e taurourso-desossicolico. Test biologici e di relazione struttura-attività sui nuovi ibridi hanno mostrato come la citoselettività sia guidata principalmente dalla natura dell'acido biliare e possa essere affinata dalla natura del nucleoside. L’abilità degli acidi biliari come molecole carrier è stata sfruttata anche nel terzo lavoro: qui l’acido ursodesossicolico e altre molecole lipofiliche sono stati coniugati ad un oligonucleotide antisenso in grado di associarsi all’esone del gene della distrofina umana che è più di frequente responsabile della Distrofia Muscolare di Duchenne, in modo da migliorarne l’exon skipping. Per la sintesi dell'oligonucleotide è stata utilizzata la chimica classica del fosforoammidito in fase solida, impiegando l'oligosintetizzatore "Äkta Oligopilot Plus". Attraverso l’inserimento di adeguati linker amminici alle estremità 3' e 5' dell’oligonucleotide e all’attivazione dei gruppi carbossilici presenti sulle molecole lipofiliche come esteri N-succinimmidici, è stato possibile realizzare la bioconiugazione per mezzo di legami ammidici. In seguito ai test eseguiti in vitro e in vivo, è emerso un effettivo aumento della quantità di distrofina nelle cellule muscolari trattate con l’oligonucleotide coniugato con l’acido ursodesossicolico rispetto a quelle trattate con l’oligonucleotide non coniugato. Nell’ultimo lavoro di questa tesi, la bioconiugazione è stata utilizzata per realizzare composti biomimetici di UDP-GlcNAc, substrato naturale di glicosiltransferasi, nei quali il β-fosfato è stato rimpiazzato da una catena alchilica o da un anello triazolico. Questi nuovi composti sono poi stati studiati come inibitori di glicosiltransferasi, in quanto la disregolazione di questi enzimi è connessa a vari disturbi, tra cui cancro e malattie neurodegenerative. L’uridina monofosfato è stata coniugata con glucosio, N-acetilglucosammina o con un anello pirrolidinico sostituito in vari modi. Test enzimatici, spettroscopici e computazionali sono risultati in accordo, evidenziando come l’assenza del β-fosfato debba essere adeguatamente controbilanciata nei glicomimetici per avere inibizione a concentrazioni micromolari.
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Mansour, Ali Taher. "New enantioselective transformations induced by cyclodextrins : applications in the preparation of molecular building blocks of biological interest". Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS186/document.
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Le but de ce travail était la préparation de dérivés cyclobutaniques du GABA optiquement purs et leur utilisation dans la préparation de γ/α-peptides pouvant adopter une structure tridimensionnelle bien définie. Pour cela, deux stratégies ont été développées. La première consistait en l’utilisation de la β-Cyclodextrine comme hôte supramoléculaire chirale lors de cyclizations photochimiques énantiosélectives. La tentative de cyclisation [2+2] intramoléculaire du N-allyl-N-(4-methoxyphenyl)acrylamide n’a conduit qu’à un δ-lactame issu d’une électrocyclisation 6π. L’électrocyclisation de la 1,3-dihydro-2H-azepin-2-one nous a permis d’obtenir le γ-latame bicyclique précurseur du (+)-cis-3,4CB-GABA avec un excès énantiomérique de 45%. La deuxième stratégie était basée sur une synthèse racémique du N-Boc-cis-3,4CB-GABA suivi d’une séparation des deux énantiomères par CLHP semi-préparative avec une colonne chirale. Les (-) et (+)-cis-3,4CB-GABA optiquement purs ont ainsi été obtenu à l’échelle du gramme. Ces deux énantiomères (-) et (+)-cis-3,4CB-GABA ont ensuite été utilisés pour la préparation de deux séries de peptides mixtes γ/α, diastéréoisomères [(S,S/R) et (R,R/R)] à courtes chaines contenant alternativement le cis-3,4CB-GABA et le D-Alanine. L'analyse des conformations des dipeptides des deux séries par Diffraction des Rayons X, n'a montré aucune interaction intramoléculaire mais plutôt un assemblage de liaisons d'hydrogène intermoléculaires entre les molécules du dipeptide. D'autre part, les études RMN 1D et 2D (en solution) ont montré que le tétrapeptide des séries (S,S/R) pourraient avoir une structure hélicoïdale 12/10, tandis que son analogue diastéréoisomères des séries (R,R/R), a montré, en solution, une nouvelle structure sous forme de ruban 7/9This work revolves around the synthesis of ennatiomerically pure cyclobutane derivatives of GABA, and their use in the preparation of hybrid γ/α-peptides that could adopt a well-defined three dimensional secondary structure. In this aim we developed two strategies. The first one employed native β-Cyclodextrin as a supramolecular chiral host to achieve enantiodifferentiating photochemical cyclizations. Attempting to perform an intramolecular [2+2] cyclization of N-allyl-N-(4-methoxyphenyl)acrylamide, we only obtained a δ-lactam resulting from a 6π electrocyclization, whereas the electrocyclization of 1,3-Dihydro‑2H‑azepin-2-one allowed access to a 45% enantiomerically enriched bicyclic γ-lactam precursor of (+)-cis-3,4CB-GABA. The second strategy was based on a racemic synthesis of N-Boc-cis-3,4CB-GABA followed by a separation of the two enantiomers using a semi-preparative HPLC fitted with a chiral column. This allowed access to optically pure (-) and (+)-cis-3,4CB-GABA, on a gram scale. Furthermore, the enantiomerically pure (-) and (+)-cis-3,4CB-GABA, were used to synthesize, and fully characterize two series [the (S,S/R) and the (R,R/R)] of short diasteriomeric hybrid γ/α-peptides composed of alternating cis-3,4CB-GABA and D-Alanine. Analysis of the conformational behavior of the dipeptides from both series by X-Ray diffraction on a single crystal, showed no intramolecular interactions but rather an array of intermolecular hydrogen bonding between the dipeptide molecules. On the other hand, a series of 1D and 2D NMR experiments showed that the tetrapeptide of the (S,S/R)-series could attain a 12/10 helical structuration, whereas its diasteriomeric analog of the (R,R/R)-series, displayed evidence of an unprecedented 7/9 folding pattern in solution
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Mukherjee, A. "Computational studies on the effect of charge and electric fields on systems of chemical and biological interest". Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2021. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/6002.
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Electric field is a phenomenon that encompasses every area of science on account of its sheer importance in every area of scientific research. External field is closely intertwined to charged species and is a useful tool to understand electrostatic interaction in such systems. Understanding the interaction between an electric field and chemical/biological systems of interest is an emerging area of research. In this chapter, we will provide a brief introduction to the concept of electric field, its relation to charge and its widespread applicability in our daily life. Also, we shall shed light on the instances of recent theoretical and experimental studies directed towards unraveling the role of external and internal electric field in relevant systems.AcSIR
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Magro, Alexandra Marques dos Santos. "Os coccinelídeos dos citrinos: estudo comparativo do seu interesse em luta biológica". Doctoral thesis, Universidade de Évora, 1997. http://hdl.handle.net/10174/11522.
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Vivemos, hoje, num mundo de estranhos paradoxos: 800 milhões de seres humanos sofrem de subnutrição (Lehman, 1996) enquanto os mercados dos países industrializados se debatem com excessos de produção; a população mundial triplica nos últimos 60 anos mas o solo arável diminui 17 % desde 1945 (Tickell, 1996). A este temível cenário aliam-se a poluição da água, do solo e da atmosfera e a extinção de milhares de espécies. Admirável mundo novo...
Primeira geração consciente (sempre? totalmente?) da fragilidade do planeta, procuramos definir políticas de solução em cimeiras como a Conferência das Nações Unidas sobre o Ambiente e o Desenvolvimento, também designada Cimeira do planeta Terra (em Junho de 1992 no Rio de Janeiro), ou a Cimeira Mundial da Alimentação, organizada pela FAO - Food and Agricultura Organization (em Novembro de 1996 em Roma). Infelizmente, as decisões finais destes encontros vêem fortemente diminuídas as suas vias de acção. face a' acordos do comércio mundial que se desenvolvem paralelamente e que, não tendo em conta preocupações ecológicas, são dominados por visões de Curto prazo.
Pouco a pouco, porém, a opinião pública ganha, para este problema essencial, uma crescente consciência, sensibiliza-se e manifesta-se; os grupos de pressão surgem, as medidas, a vários níveis, procuram despontar. 'Desenvolvimento sustentável" é uma expressão que está cada vez mais presente no discurso daqueles que se preocupam com o destino da Terra e dos
1
que nela vivem. Segundo a definição da World Conservation Union, do United Nations Environment Programme e do World Wide Fund for Nature (IUCNXTNEP/WWF, 1991), uma actividade é sustentável, em termos práticos, se pode desenvolver-se para sempre. Tickell (1996) acrescenta: "mudança durável para melhor, protegendo a terra que herdámos e que deixamos em herança'.
Mudanças que implicam intervenções a vários níveis - de actividade, de poder - que interferem na própria base da sociedade e da sua organização, pois requerem novos valores...
A agricultura está no centro das atenções, com principais consequências nos países desenvolvidos do Norte do globo. Estes países mantêm políticas agrícolas que fomentam sobretudo a produção.. Consequentemente, esta baseia-se na utilização de enormes doses de fertilizantes e pesticidas e elevados investimentos de energias não-renováveis; que conduzem a desequilíbrios ecológicos e empobrecimento dos solos. Como, de maneira elegante, afirma Pisam (1994), a produção alimentar é progressivamente desviada das leis da natureza para ser submetida às leis do mercado, operação rentável, sem dúvida, pois que encontra capital de investimento disponível, mas prática da qual ninguém sabe quais serão, a longo prazo, os efeitos e custos. ### / Abstract /- The present work aims to contribute to our knowledge of the biological control of citrus pests in Portugal, using coccinellids. Field studies were developed in order to evaluate the more interesting species (Chapters 1 and 2) and they were followed by analysis of life history strategies of two coccinellids (Chapter 3).
39 species of coccinellids were identified, 36 of which are predators. Nephus fuerschi Plaza is refered for the first time to Portugal.
Maps of species distributions are presented: 5 seem to have an aggregated distribution. Nephus reunioni Fürsch and Nephus includens (Kirsch) separate themselves from these 5 by being very abundant. Previous studies about these two coccinellids distributions are confirmed: N. reunioni is limited to a region of about 80 Km diameter around Lisbon and N. includens appeared only m Algarve. In those regions they are both more abundant: than the other mealybugs predator, Cryptolaemus montrouzieri Mulsant.
A 69 % correlation is observed between the degree of dispersion and dominance values. Scymnus mediterraneus Khnzorian e Scymnus interruptus (Goeze) occupy the first places for both parameters.
Coccidiphagous species and a group of Scymnus sp. And Nephus sp., with unknown prey habits, are the most important in terms of richness and abundance.
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Santos, Figueroa Luis Enrique. "New approaches for the development of chromo-fluorogenic sensors for chemical species of biological, industrial and environmental interest". Doctoral thesis, Universitat Politècnica de València, 2015. http://hdl.handle.net/10251/43216.
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El presente proyecto de investigación está enfocado al desarrollo de sensores químicos fluoro-cromogénicos, para la detección y determinación de especies químicas de interés biológico, industrial y medioambiental de forma selectiva y con alta sensibilidad.
En forma general, se busca el diseñar nuevos sistemas sensores basados en compuestos (receptores) formados por dos unidades: una unidad coordinante que interacciona con el anión a determinar y una unidad generadora de señal que alerta del reconocimiento molecular efectuado.
Durante este estudio se están preparando diversas moléculas receptoras funcionalizandas con grupos modificadores de estructura para evaluar su influencia sobre las capacidades de detección y selectividad como receptores de especies específicas en diferentes condiciones y medios.
Las diferentes aproximaciones en prueba implican a su vez el diseño y síntesis molecular, así como el análisis de las diferentes señales ópticas producidas en el reconocimiento, con el fin de diseñar sistemas de alta eficacia y eficiencia, y con posibilidades reales de aplicación.Santos Figueroa, LE. (2014). New approaches for the development of chromo-fluorogenic sensors for chemical species of biological, industrial and environmental interest [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/43216
TESIS
Premiado
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Fernandes, João Roberto. "Metodologias analiticas enzimaticas para analise de oxalato em amostras de interesse biologico". [s.n.], 1996. http://repositorio.unicamp.br/jspui/handle/REPOSIP/250393.
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Orientadores: Graciliano de Oliveira Neto, Matthieu TubinoTese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica
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Doutorado
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Conti, Irene <1976>. "Fotofisica e fotochimica di sistemi organici coniugati di interesse biologico e tecnologico". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amsdottorato.unibo.it/1039/1/Tesi_Conti_Irene.pdf.
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Conti, Irene <1976>. "Fotofisica e fotochimica di sistemi organici coniugati di interesse biologico e tecnologico". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amsdottorato.unibo.it/1039/.
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Sousa, Thiago Machado Mello de. "Produção de proteínas de interesse terapêutico em células de mamíferos em cultura". reponame:Repositório Institucional da UnB, 2006. http://repositorio.unb.br/handle/10482/3228.
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Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Biologia Celular, 2006.Submitted by wesley oliveira leite (leite.wesley@yahoo.com.br) on 2009-11-25T16:14:58Z No. of bitstreams: 1 Dissert Thiago Machado Mello de Sousa.pdf: 1918195 bytes, checksum: 76ffa4fe871a3a0f8ce3aff26c2c0b09 (MD5)
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As proteínas recombinantes de interesse terapêutico vêm ganhando cada vez mais espaço na indústria farmacêutica e atualmente já movimentam um mercado anual de cerca de 50 a 60 bilhões de dólares em todo o mundo. As células de mamíferos são as hospedeiras de expressão preferencialmente escolhidas no caso de proteínas que requerem um grau sofisticado de processamento pós-traducional, sendo crescente a iniciativa de identificação de novas linhagens de células, especialmente humanas, como sistemas alternativos de expressão às células utilizadas. Nosso grupo de pesquisa tem interesse na produção de antígenos para seleção de anticorpos com potencial neutralizante, especialmente os antígenos de superfície do envelope viral de HIV-1, agente etiológico da pandemia mundial de AIDS, que atualmente apresenta mais de 40 milhões de infectados. O presente trabalho teve por objetivo a avaliação preliminar das células de ducto de glândula submandibular humana (HSG) como sistema de expressão heteróloga alternativo às células de ovário de hamster chinês (CHO-K1). Comparativamente, foi avaliada a eficiência de transfecção, assim como a de expressão transiente do anticorpo quimérico anti-Z-DNA Z22, na forma recombinante de fragmento FvFc pelas duas linhagens celulares. Outro objetivo foi a produção de versões recombinantes das glicoproteínas virais de HIV-1. Os resultados apontaram as células HSG como um bom sistema alternativo para a produção de proteínas heterólogas secretadas, especialmente quando transfectadas por co-precipitação com fosfato de cálcio, sendo ainda necessários alguns ajustes, uma vez que os choques osmóticos com glicerol e DMSO, considerados pontencializadores da transfecção, mostraram-se tóxicos da forma como foram executados. Foram amplificados e clonados em vetor de expressão para células de mamíferos os segmentos gênicos correspondentes a quatro versões recombinantes das glicoproteínas do envelope viral de HIV-1 (gp160, gp140, gp120 e gp41+PS), subtipo C que, de acordo com as nossas análises, utiliza CCR5 como co-receptor. Até o presente momento, não foi possível a detecção das glicoproteínas recombinantes, expressas de forma transiente em células CHO-K1, sendo necessários ajustes, principalmente na etapa de transfecção. _______________________________________________________________________________ ABSTRACT
Recombinant therapeutic proteins have become more and more important in the pharmaceutical industry, and nowadays they are responsible for an injection of about 50 to 60 million dollar a year into the worldwide market. Animal cell cultures are the preferential expression systems for those proteins which require extensive posttranslational modifications. In this view, the identification of alternative expression systems is an issue of increasing concern, specially considering human cell lines. Our research group has been interested in the production of antigens to be used for the selection of neutralizing antibodies, particularly those antigens derived from the envelope surface of HIV-1, the etiologic agent of the pandemic infection of AIDS, which nowadays affects more than 40 million people. This work aimed the preliminary evaluation of the human salivary gland duct cells (HSG) as a heterologous expression system alternative to the Chinese hamster ovary cells (CHO-K1). The transfection efficiency for both cell lines was comparatively evaluated, as well as the transient expression of the anti-Z-DNA Z22 chimeric antibody, as a recombinant FvFc fragment. Another objective was the production of recombinant versions of HIV-1 glycoproteins. Our results pointed out to the HSG cells as a good alternative system for the production of secreted heterologous proteins, specially when transfected by co-precipitation with calcium phosphate. Some adjusts are still needed, considering that the glycerol and DMSO osmotic shocks, generally considered as transfection pontentializers, proved to be toxic in the employed protocol. The genic fragments corresponding to four recombinant versions of the HIV-1 envelope glycoproteins (gp160, gp140 gp120 and gp41+PS), subtype C, were amplified and cloned in a mammal cells expression vector. According to our analysis, this virus subtype uses CCR5 as co-receptor. So far, it was not possible to detect the recombinant glycoproteins expressed in a transient form in the CHO-K1 cells. In order to achieve this objective, some adjustments are still necessary, specially concerning the transfection protocol.
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Pinto, Ines Mendes. "O interesse de professores pelo estudo da Biologia: manifestações atuais e memórias". Universidade Federal de Minas Gerais, 2009. http://hdl.handle.net/1843/BUOS-9M2MBV.
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In this research, we seek lo understand the relationship between personal interests for the study of the different Biology themes and experiences in the learning of Science over the life of Biology and Science teachers. To this end, wc carried out theoretical and empirical studies
that integrate qualitative and quantitative methods about; a) translation and adaptation of the Study Interest Questionnaire (SIQ) to the Interest for the Study of Biology fhemes Questionnaire (Questionário dc Interesse Pelo Estudo de Temas de Biologia - QlB fB) and the profile of current personal interests for the study of Biology themes; b) individual and
situational aspects in the reminded episodes on Science learning over the life; c) individual and situational structures in reminded episodes on Biology learning; d) correlation between the current personal interests for the study of Biology themes and the individual and situational structures in the reminded episodes on Biology learning over the life, 'fhe participants of the research currently work as Science and Biology teachers in elementary and high school, in public schools of various cities of Minas Gerais state (Brazil), fhe study themes of great interest for teachers are, in descending order: Ecology, Genetics/Evolution, Living Beings, Anatomy/Physiology and Cytology/Histology. The interest in the study of different Biology themes has got very similar distribution among Science and Biology teachers. The strong correlations between the interests indicate the existence of a general interest for the study of Biology that captures what it has in common to all interests and represents teachers' interest for the area of Biological Sciences. The questionnaire for the identification and measurement of personal interests for the Biology themes, used in this research, might be refined to be used in future in international comparative studies, fhe teachers' reminded episodes were analyzed, considering the personal affective-emotional aspects and the situational aspects related to time, place and characteristics of the learning environment. In the structure of the episodes, the dimensions called: Motivation, Selfefficacy,
Ecology, Lack of Motivation and Embarrassment are identified, fhe importance of the activities developed in elementary school, which were reminded in the episodes, points to the need of improvement in the Science activities, at school early years. The correlations between the structures of the current interests and the individual and situational structures in the episodes are analyzed, in defined groups, taking into account the area of professional activity, gender and time of teaching. The strong correlations between personal interests for the study of Biology themes and Ecological dimension suggest great approach between scientific knowledge and life. Although the Ecology is, in the results of our research, a family dimension, it provides guidance for school interventions that might promote the origin and development of interests for the study of Biology curricula themes, fhe study of correlation
shows a symmetrical relationship between the structures of the interests and the dimensions of the episodes, however it does not establish a How of causality, which might be further investigated in future, in an intra-individual longitudinal investigation.Nesta pesquisa, buscamos compreender as relações entre os interesses pessoais pelo estudo de diferentes temas de Biologia c as experiências vivcnciadas na aprendizagem de Ciências ao longo da vida de professores de Ciências e dc Biologia. Com esse propósito, realizamos estudos teóricos e empíricos que integram métodos qualitativos e quantitativos sobre: a) tradução e adaptação do Study Interest Questionnaire (SIQ) para o Questionário dc Interesse Pelo Estudo de Temas de Biologia (QIETB) e o perfil de interesses de professores pelo estudo de temas dc Biologia; b) aspectos individuais e situacionais de episódios rememorados sobre aprendizagem dc Ciências ao longo da vida; c) estruturas individuais c situacionais nos episódios rememorados sobre aprendizagem de Biologia; d) correlações entre os interesses pessoais atuais pelo estudo dc temas de Biologia c as estruturas individuais c situacionais nos episódios rememorados sobre aprendizagem de Biologia. Os participantes da pesquisa atualmente atuam como professores dc Ciências c Biologia no ensino fundamental e médio, em escolas públicas dc várias cidades do estado de Minas Gerais. Os temas de estudo de maior interesse dos professores são, em ordem decrescente: Ecologia, Genética/Evolução, Seres Vivos, Anatomia/Fisiologia c Citologia/1 listologia. O interesse pelo estudo de diferentes temas de Biologia tem distribuição muito parecida entre professores de Ciências c de Biologia. As fortes correlações entre os interesses indicam a existência de um interesse geral pelo estudo de Biologia, que captura o que tem de comum em todos os interesses e representa o interesse dos professores pela área dc Ciências Biológicas. O questionário de identiíicação c de mcnsuração de interesses pessoais pelos temas de Biologia, utilizado nesta pesquisa, pode ser aprimorado para ser utilizado futuramente em estudos comparativos internacionais. Os episódios rememorados pelos professores foram analisados, considerando os aspectos pessoais afctivo-emocionais c os aspectos situacionais relativos ao tempo, local c características do ambiente de aprendizagem. Na estrutura dos episódios, são identillcadas as dimensões denominadas de Motivação, Autocficácia, Ecologismo, Dcsmotivação e Constrangimento. A importância das atividades desenvolvidas no ensino fundamental, rememoradas nos episódios, aponta para a necessidade de aprimoramento das atividades de Ciências nos primeiros anos escolares. As correlações entre as estruturas dos interesses atuais e as estruturas individuais e situacionais nos episódios são analisadas nos grupos definidos por área dc atuação profissional, gênero e tempo de magistério. As fortes correlações entre interesses pessoais pelo estudo de temas de Biologia e a dimensão lícologismo sugerem maior aproximação entre o conhecimento científico e a vida. Apesar de iicologismo ser, no resultado de nossas pesquisas, uma dimensão familiar, ela fornece orientação para intervenções escolares que podem favorecer a origem e o desenvolvimento de interesses pelo estudo de temas curriculares de Biologia. O estudo de correlações que realizamos indica uma relação simétrica entre as estruturas dos interesses e as dimensões dos episódios, entretanto não estabelece obrigatoriamente um lluxo de causalidade, o qual poderá ser investigado futuramente numa investigação intraindividual longitudinal mais detalhada.
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TOLOZA, CARLOS ALBERTO TOLOZA. "SPECTROANALYTICAL METHODS USING GRAPHENE QUANTUM DOTS AS PHOTOLUMINESCENT PROBES FOR THE DETERMINATION OF ANALYTES OF BIOLOGICAL AND PHARMACOLOGICAL INTEREST". PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2018. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=35904@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
FUNDAÇÃO DE APOIO À PESQUISA DO ESTADO DO RIO DE JANEIRO
PROGRAMA DE SUPORTE À PÓS-GRADUAÇÃO DE INSTS. DE ENSINO
BOLSA NOTA 10
O presente trabalho teve como objetivo o desenvolvimento de métodos espectroanalíticos capazes de determinar indiretamente analitos de interesse biológico e farmacológico que possuem fraca atividade óptica no UV-vis (no caso, captopril, histamina e sulfato de canamicina). Embora muitos métodos para quantificar esses analitos estejam reportados, muitos dependem da derivatização química do analito, procedimento considerado complexo e trabalhoso para fazer tais analitos absorverem e emitirem no UV-vis. Por isso, a proposta de uso de pontos quânticos fotoluminescentes é interessante, pois permitem, em condições ajustadas, respostas analíticas que proporcionam a determinação indireta dos analitos de interesse em concentrações da ordem de até 10-8 mol L-1. A determinação do captopril foi proposta utilizando pontos quânticos de grafeno aminofuncionalizados com uso de glutationa (GQDs-amino). O captopril induziu a supressão e o deslocamento espectral (para o vermelho) da fotoluminescência da dispersão aquosa dos GQDs-amino. Por outro lado, quando Fe3+ foi usado como um mediador que gera uma supressão da fotoluminescência da dispersão de GQDs-amino, a adição de captopril restabelece a fotoluminescência original dos pontos quânticos. Em condições experimentais ajustadas, a magnitude da supressão ou de deslocamento espectral da fotoluminescência dos GQDs-amino pode ser relacionada com a concentração de captopril. Em ambos os casos, a resposta linearizada abrangeu três ordens de grandeza (10-6 a 10-4 mol L-1). Em contrapartida, a abordagem de restauração do sinal da sonda, previamente suprimida com Fe3+, também se mostrou útil do ponto de vista analítico. As abordagens propostas foram testadas com a determinação de captopril em amostras simuladas e em formulações farmacêuticas comerciais. O deslocamento 10 espectral a partir da sonda GQDs-amino e ativação/desativação da fotoluminescência utilizando GQDs-amino-Fe3+ resultou em recuperações satisfatórias, mostrando o potencial de detecção quantitativo do método. No estudo com a histamina, avaliou-se o comportamento fotoluminescente da dispersão aquosa de GQDs-amino na presença de histamina com interação mediada por diferentes íons metálicos. Os resultados revelaram que uma interação mais forte e seletiva existia na presença de Eu3+, Fe3+ e Cu2+. A sensibilidade das curvas de supressão de fotoluminescência normalizada (Ks) indicou uma interação dez vezes mais forte da histamina com a superfície dos GQDs na presença de Fe3+. A resposta linear observada nos GQDs-amino-Fe3+ (luminescência medida a 345/435 nm) abrangeu a concentração de histamina de 4,3 × 10-7 mol L-1 (limite de quantificação) até 3,2 × 10-5 mol L-1. A dispersão de GQDs-amino-Fe3+ foi usada como sonda na análise de amostras de atum após extração do analito em cartucho fase sólida catiônica. Os resultados analíticos foram estatisticamente semelhantes aos obtidos com um método baseado na cromatografia líquida com detecção fluorimétrica (após derivatização química da histamina). A determinação do sulfato de canamicina foi feita medindoo efeito que ela exerce sobre a fotoluminescência dos GQDs-amino associados às nanopartículas de ouro (AuNPs), que foram produzidas pela redução de AuCl4 com NaBH4 em uma dispersão aquosa de GQDs-amino (obtido pela pirólise de ácido cítrico e glutationa) contendo também o agente tensoativo catiônico CTAB. O sistema AuNPs-GQDs-amino-CTAB apresentou fotoluminescência suprimida, que foi amplificada na presença de canamicina. Sob condições experimentais ajustadas, a ampliação da fotoluminescência do nanomaterial em função da concentração de analito se mostrou linear e abrangeu três ordens de grandeza (10-7 a 10-5 mol L-1). O uso de extração em fase sólida com um cartucho empacotado com um polímero molecularmente impresso (seletivo para aminoglicosídeos) assegurou a seletividade nas determinações de sulfato de canamicina feitas em vacina da febre amarela e em formula�
The objective of the present work was the development of spectroanalytical methods capable of indirectly determining analytes of biological and pharmacological interest that present inherent weak optical activity in UV-vis (in this case, captopril, histamine and kanamycin sulfate). Although many methods to quantify these analytes are reported, many of these depend on chemical derivatization, a procedure considered complex and laborious to promote UV-vis absorption and luminescence. Therefore, the proposed use of photoluminescent quantum dots is interesting since they allow, under adjusted conditions, analytical responses that allow the indirect determination of the analytes of interest in concentrations of the order of down to 10-8 mol L-1. The determination of captopril was proposed using graphene quantum dots aminofunctionalized using glutathione as a precursor (GQDs-amino). Captopril induced photoluminescence suppression and spectral red-shift from the aqueous dispersion of GQDs-amino. In contrast, when Fe3+ is used as a mediator, it generates a suppression of the photoluminescence of the GQD-amino dispersion and the addition of captopril restored the original photoluminescence of the quantum dots. In adjusted experimental conditions, photoluminescence suppression of the GQDs-amino, as a function of the captopril concentration, can be related both to the magnitude of the suppression and to the spectral shift. In both cases, the linearized response covered three orders of magnitude (10-6 to 10-4 mol L-1). In contrast, the probe signal restoration of the previously Fe3+ suppressed photoluminescent GQDs, also proved to be analytically useful. The proposed approaches were tested by the determination of captopril in simulated samples and in commercial pharmaceutical formulations. Spectral shift from the GQDs-amino probe and the photoluminescence on/off approach (using GQDs-amino-Fe3+ probe) resulted in satisfactory recoveries, showing the quantitative capability of the method. In the work concerning histamine, the photoluminescent behavior of the aqueous dispersion of GQDs-amino in the presence of this amino acid was studied in function of different interaction mediators (metal ions). The results revealed that strong and selective interaction existed in the presence of Eu3+, Fe3+ and Cu2+. The sensitivity of normalized photoluminescence (Ks) suppression curves indicated a ten-fold stronger interaction of histamine with the surface of GQDs in the presence of Fe3+. The linear response observed in the GQDs-amino-Fe3+ (luminescence measured at 345/435 nm) covered the histamine concentration of 4.3 × 10-7 mol L-1 (quantification limit) to 3.2 × 10-5 mol L-1. The GQDs-amino-Fe3+ was applied as a probe in the analysis of tuna fish samples after solid phase extraction (SPE) of the analyte using a cationic solid phase. The analytical results were statistically similar to those obtained with a method based on liquid chromatography with fluorimetric detection (after chemical derivatization of histamine). The determination of kanamycin sulfate was made by measuring the effect it exerts on the photoluminescence of gold nanoparticles (AuNPs) associated GQDs, that were produced by the reduction of AuCl4 with NaBH4 in an aqueous dispersion of GQDs-amino (obtained by pyrolysis of citric acid and glutathione) also containing the cationic surfactant CTAB. The AuNPs-GQDs-amino-CTAB system showed a suppressed photoluminescence, which was amplified in the presence of kanamycin. Under adjusted experimental conditions, the magnification of the photoluminescence of the nanomaterial as a function of the analyte concentration was linear and covered three orders of magnitude (10-7 to 10-5 mol L-1). The use of solid phase extraction with a cartridge packed with a molecularly imprinted polymer (selective for aminoglycosides) ensured selectivity in the determinations made in yellow fever vaccine and in veterinary pharmaceutical formulations. The analytical results were statistically similar to those obtained with an HPLC based method with fluorimetri
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Ferlizza, Enea <1985>. "Urine proteome in animals of veterinary interest: species comparison and new biomarkers of nephropathy". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/6817/1/Ferlizza_Enea_Tesi.pdf.
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Urine is considered an ideal source of biomarkers, however in veterinary medicine a complete study on the urine proteome is still lacking. The present work aimed to apply proteomic techniques to the separation of the urine proteome in dogs, cats, horses, cows and some non-conventional species. High resolution electrophoresis (HRE) was also validated for the quantification of albuminuria in dogs and cats.
In healthy cats, applying SDS-PAGE and 2DE coupled to mass spectrometry (MS), was produced a reference map of the urine proteome. Moreover, 13 differentially represented urine proteins were linked with CKD, suggesting uromodulin, cauxin, CFAD, Apo-H, RBP and CYSM as candidate biomarkers to be investigated further.
In dogs, applying SDS-PAGE coupled to MS, was highlighted a specific pattern in healthy animals showing important differences in patients affected by leishmaniasis. In particular, uromodulin could be a putative biomarker of tubular damage while arginine esterase and low MW proteins needs to be investigated further.
In cows, applying SDS-PAGE, were highlighted different patterns between heifers and cows showing some interesting changes during pregnancy. In particular, putative alpha-fetoprotein and b-PAP needs to be further investigated.
In horses, applying SDS-PAGE, was produced a reference profile characterized by 13±4 protein bands and the most represented one was the putative uromodulin. Proteinuric horses showed the decrease of the putative uromodulin band and the appearance of 2 to 4 protein bands at higher MW and a greater variability in the range of MW between 49 and 17 kDa.
In felids and giraffes was quantified proteinuria reporting the first data for UTP and UPC. Moreover, by means of SDS-PAGE, were highlighted species-specific electrophoretic patterns in big felids and giraffes.