This dissertation explores the innovative integration of optical trapping (OT) with advanced laser spectroscopy techniques to investigate the physicochemical properties of single particles from a variety of atmospheric aerosols, such as bioaerosols, terrestrial dust, and extraterrestrial dust. Each technique offers unique insights, significantly enhancing our understanding of these critical atmospheric components. The first work focuses on employing OT in conjunction with cavity ringdown spectroscopy (OT-CRDS) to measure the single-particle extinction of interplanetary dust particles at ultraviolet wavelengths (~308 nm). This method allows for the stable trapping of individual dust particles in air, facilitating precise characterization with minimal external interference. Our findings illustrate that the integration of OT with cavity ringdown spectroscopy serves as a novel tool for obtaining multimodal information on IDPs, thus providing new avenues for understanding planetary phenomena and their implications for atmospheric science. In the second work of the dissertation, we investigate the capabilities of optical trapping-Raman spectroscopy (OT-RS) for the characterization, identification, and detection of aerosol particles in their native atmospheric states. We constructed a comprehensive library of OT-RS fingerprints from various aerosol categories, including bioaerosols, terrestrial dust, and extraterrestrial dust. This library addresses significant challenges in particle identification and serves as a crucial reference for future atmospheric studies. The advantages of single-particle characterization through OT-RS are highlighted, demonstrating its potential for advancing our understanding of aerosol behavior in the atmosphere. The third study integrates optical trapping with circular intensity differential scattering (OT-CIDS) to analyze single biological particles, highlighting its potential for detecting chiral structures like DNA and RNA. Using a custom-designed elliptical reflector, we achieve optical levitation to measure angle-dependent scattering without interference from surrounding equipment. Our results demonstrate the feasibility of capturing two-dimensional angular optical scattering (TAOS) patterns, revealing distinct angular responses from various levitated particles. In summary, this dissertation presents a groundbreaking interaction between optical trapping and advanced spectroscopic techniques, offering innovative methodologies for studying the intricate properties of single particles in atmospheric science and beyond. The insights gained from this research contribute significantly to our understanding of atmospheric phenomena and open new avenues for particle characterization and environmental monitoring across diverse contexts.

Opioid use disorder (OUD) is chronic relapse neurological disorder, best characterized by profound drug-induced neuroadaptations which drive drug-seeking phenotypes and persist in the absence of drug. In this dissertation we will examine circular RNA (circRNA) dysregulation following a rodent model of heroin self-administration and characterize a novel circRNA pathway regulating opioid induced neuroadaptations. We identified 76 circRNAs regulated by heroin self-administration, of these we selected circGrin2b_011731 (circGrin2b) for further characterization. circGrin2b is derived from exon 3 of linear Grin2b, which encodes the regulatory subunit of the NMDA receptor, GluN2b, a protein essential for opioid learning and memory paradigms. First, using a custom small-interfering RNA (siRNA) targeting the backsplice junction of circGrin2b, we show that knock-down of orbitofrontal cortex (OFC) circGrin2b significantly reduces heroin intake during self-administration, while only non-significantly reducing heroin-seeking phenotypes. This suggests that OFC circGrin2b is functionally relevant to heroin self-administration phenotypes. Next, we utilized an in vitro primary cortical culture morphine exposure model to interrogate putative upstream biogenesis mechanisms and examine expression of potential circGrin2b microRNA (miRNA)-sponge targets. We validated circGrin2b interactions with miR-26b-3p and miR-100-3p utilizing a luciferase binding assay. Sponging of these 2 miRNA targets can have extensive impact of translation of miRNA-repressed genes, as both miRNAs are involved in regulation of messenger RNAs involved in opioid signaling. Taken together, this dissertation characterized the behavioral and molecular role of a novel circRNA species in mediating opioid-induced neuroadaptations and expands upon the current understanding of the role of circRNAs in regulating synaptic plasticity. / Biomedical Sciences

Die schnelle Urbanisierung weltweit treibt die Expansion, Erneuerung und Modernisierung der gebauten Umwelt, die als Raum für menschliches Wohnen und gesellschaftliches Handeln dient, voran. Dieses Wachstum hat zu einem erheblichen Ressourcenverbrauch und Emissionen geführt, die die globale Ressourcengewinnung und den Klimawandel beeinflussen. Daher ist das Verständnis der Ressourcendynamik innerhalb der gebauten Umwelt von entscheidender Bedeutung. Auf Grundlage dieses Verständnisses kann die Entwicklung von Aktivitäten der Kreislaufwirtschaft (CE) den Ressourcenaufwand und Umweltprobleme mindern, eine effiziente Ressourcennutzung fördern und den Übergang zur CE in der gebauten Umwelt erleichtern. Die Zirkularität von Baumaterialien variiert aufgrund der Unterschiede in den räumlichen Kontexten im geografischen Sinne erheblich, sodass identische CE-Strategien und sie antreibende technische Innovationen (TIs) nicht in allen Regionen anwendbar sind. Die aktuelle Forschung liefert oft fragmentierte und teilweise unvollständige Einblicke in die räumlichen Auswirkungen und Anwendungen von TIs innerhalb der zirkulären gebauten Umwelt; beispielsweise werden oft nur einzelne CE-Strategien untersucht, lokale räumliche Kontexte häufig vernachlässigt und es fehlt an dynamischen Bewertungen von TIs. Folglich bleibt es eine Herausforderung, die Dynamik von Baumaterialien systematisch zu verstehen und zu analysieren sowie geeignete Strategien und TIs anzuwenden, um ihrer Zirkularität zu verbessern. Diese Dissertation zielt darauf ab, den Einfluss von TIs in unterschiedlichen räumlichen Kontexten hinsichtlich der Materialdynamik in der gebauten Umwelt zu untersuchen und die Frage zu beantworten: „Wie wirken sich TIs und räumliche Merkmale auf die Zirkularität der gebauten Umwelt aus?“ Basierend darauf wird die Hypothese aufgestellt, dass die Anpassung von TIs an lokale Kontexte den Beitrag von CE-Strategien zur Ressourceneffizienz in der gebauten Umwelt verbessern kann. Zu diesem Zweck wird ein methodologischer Rahmen gesetzt, der sich auf die Materialflussanalyse (MFA) stützt und Bibliometrie, Systemdynamik, dynamische MFA (dMFA), kontinuierliche MFA (cMFA) sowie Lebenszyklusbewertung (LCA) integriert. Dieser Rahmen wird verwendet, um die linearen und zirkulären Dynamiken von Baumaterialien zu analysieren. Der auf dem MFA-Konzept basierende CE-Rahmen wird in drei Studien eingesetzt, um die Auswirkungen von räumlichen Merkmalen, TIs und Fall-TI auf die Zirkularität von Baumaterialien zu erforschen. Ausgehend von diesen Ergebnissen werden kontextspezifische CE-Strategien und entsprechende TIs vorgeschlagen, um die Materialzirkularität zu verbessern und Rohstoffe zu schonen. Darüber hinaus wird die Anwendung von Fall-TI in verschiedenen Regionen untersucht, um die Bedeutung der räumlichen Merkmale für die Zirkularität von Materialien und deren Einfluss auf die Reduzierung des globalen Erwärmungspotentials herauszuarbeiten. Erstens wurde eine Literaturrecherche durchgeführt, um Publikationen zur gebauten Umwelt und CE zu sammeln und die fragmentierten und impliziten räumlichen Informationen zu extrahieren. Diese Informationen wurden dann mithilfe des Closing-Slowing-Narrowing (CSN)-Ansatzes systematisiert. Die Ergebnisse zeigen, dass unterschiedliche räumliche Merkmale die Zirkularität von Materialien in der gebauten Umwelt durch drei Hauptstrategien beeinflussen können (CSN-Ansatz): Schließen (Schaffung geschlossener Kreisläufe zwischen Endnutzung und Produktion), Verlangsamen (Verlängerung der Lebensdauer von Produkten) und Verengen (Reduzierung des Materialverbrauchs). Die effektive Nutzung räumlicher Informationen in Regionen mit unterschiedlichen Urbanisierungsgraden kann dazu beitragen, kontextspezifische CE-Strategien zu entwerfen und so den Wert von Baumaterialien zu maximieren. Zweitens wurde mithilfe eines Systemdynamikmodells der cMFA der Einfluss von TIs unter verschiedenen CE-Strategien bezüglich der linearen und zirkulären Dynamiken von Beton, dem am meisten verwendeten Baumaterial der gebauten Umwelt, untersucht. Die Ergebnisse zeigen, dass verschiedene TIs die Systemzirkularität und Ressourceneffizienz verbessern können, indem sie die vier zirkulären Flüsse beeinflussen: Reduzieren, Wiederverwenden, Recyceln und Reparieren. Unter stabilen Bestandsbedingungen kann die kombinierte Anwendung ausgewählter TIs im Vergleich zu einem Referenzszenario (ohne TI) den Zufluss um bis zu 71 % reduzieren und den Verlust von 65 % der natürlichen Ressourcen verhindern. Dabei zeigen die Untersuchungen auch, dass die Szenarien, die mit den höchsten zirkulären Flüssen verbunden sind, nicht notwendigerweise die größten Ressourceneinsparungen erzielen. In der Praxis sollten daher die Wirkungen der zirkulären Flüsse über die bloße Maximierung der Flüsse selbst gestellt werden. Drittens und letztens zielt diese Studie darauf ab, die Ergebnisse der ersten und zweiten Schritte am Beispiel der aufstrebenden Technik der Karbonatisierung von recyceltem Betonzuschlag, die derzeit im Rahmen des CE einer ersten industriellen Anwendung unterzogen wird, zu bewerten und zu validieren. Diese Analyse bewertet Ressourcenschonungen, CO2-Emissionsreduktionen und wirtschaftliche Vorteile in verschiedenen Regionen und zeigt, dass die Verfeinerung lokalisierter technischer und räumlicher Parameter den Beitrag der TIs zu Umwelt- und Wirtschaftsziele verbessern kann. Dieses Beispiel dient als Referenz für die Bewertung der Anwendung anderer TIs in räumlichen Kontexten. In dieser Doktorarbeit wird die Integration von Systemdynamik in dMFA und cMFA Methoden innerhalb der industriellen Ökologieforschung für die gebaute Umwelt untersucht. Die Ergebnisse liefern wertvolle Erkenntnisse für die Entwicklung und Gestaltung von CE-Strategien sowie die Bewertung technischer Parameter, insbesondere für sich verstädternde Gebiete, mit dem Fokus, den Übergang der gebauten Umwelt hin zur Zirkularität aus der Lebenszyklusperspektive von Baumaterialien voranzutreiben. / Rapid urbanization worldwide is driving the expansion, renewal, and modernization of the built environment, which serves as the space for human habitation and societal operation. This growth has led to substantial resource consumption and emissions, influencing global resource extraction and climate change. Therefore, understanding resource dynamics within the built environment is essential. Developing circular economy (CE) activities based on this understanding can mitigate resource pressure and environmental issues, promote efficient resource utilization, and facilitate the transition towards a CE in the built environment. The circularity of construction materials varies significantly due to the difference in spatial contexts in the geographical sense, making identical CE strategies and the technical innovations (TIs) driving them inapplicable across all regions. Current research often provides fragmented and partial insights into the spatial impacts and applications of TIs within the circular built environment, e.g. they have typically focused on single CE strategy, frequently neglected local spatial contexts, and lacked dynamic evaluations of TIs. Consequently, it remains challenging to systematically understand and analyze the dynamics of construction materials and apply suitable strategies and TIs to enhance their circularity. This thesis aims to investigate the influence of TIs applied in different spatial contexts on material dynamics in the built environment, addressing the question: 'How do TIs and spatial characteristics impact circularity in the built environment?' Based on this, the study hypothesizes that adopting TIs according to local contexts can enhance the contribution of CE strategies to resource efficiency in the built environment. To this end, the study establishes a methodological framework centered on Material Flow Analysis (MFA), integrating bibliometrics, dynamic MFA (dMFA), continuous MFA (cMFA), and Life Cycle Assessment (LCA). This framework is used to analyze the linear and circular dynamics of construction materials. The CE framework, based on the MFA concept, is employed across three studies to explore the impact of spatial characteristics, TIs, and case TI on the circularity of construction materials. From these findings, the research proposes context-specific CE strategies and corresponding TIs to improve material circularity and conserve raw materials. Additionally, the research examines the application of case TI in different regions to underscore the importance of spatial characteristics in the materials’ circularity and its impact on reducing Global Warming Potential. Firstly, a literature review was conducted to gather publications on the built environment and CE, extracting the fragmented and implicit spatial information addressed. This information was then systematized using Closing-Slowing-Narrowing (CSN) approach. The results indicate that different spatial characteristics can influence the circularity of materials in the built environment through three main strategies (CSN approach): closing (creating closed loops between end-use and production), slowing (extending product lifespan), and narrowing (reducing material consumption). Effectively utilizing spatial information in regions with varying urbanization levels can help design context-specific CE strategies, thereby maximizing the value of construction materials. Secondly, leveraging a System Dynamics model of cMFA, the study examined the impact of TIs under different CE strategies on the linear and circular dynamics of concrete, the most consumed material in the built environment. The findings reveal that various TIs can enhance system circularity and resource efficiency by influencing the four circular flows: Reduce, Reuse, Recycle, and Repair. Under stable stock conditions, the combined application of selected TIs can reduce inflow by up to 71% and prevent the loss of 65% of natural resources compared to a reference scenario lacking such initiatives. Importantly, the study also reveals that scenarios contributing the highest circular flows do not necessarily yield the greatest resource savings. Therefore, in practical applications, the impact of circular flows should be prioritized over merely maximizing the flows themselves. Lastly, using the emerging technique of recycled concrete aggregate carbonation, which is currently undergoing preliminary industrial application within the CE framework, this study aims to evaluate the results obtained from the first and second steps. The analysis assesses resource savings, CO2 emission reductions, and economic benefits in different regions, demonstrating that refining localized technical and spatial parameters can enhance the contribution of the TIs to environmental and economic goals. This example provides a reference for evaluating the application of other TIs in spatial contexts. This doctoral thesis offers an exploration of dMFA and cMFA methodologies within industrial ecology research for the built environment. The findings provide valuable insights for designing CE strategies and evaluating technical parameters, particularly for urbanizing areas, with a focus on advancing the transition of the built environment towards circularity from a lifecycle perspective of materials.

The main objective of this thesis is the development of a nonparametric sequential estimation technique for the off-pulse interval(s) of a source function originating from a pulsar. It is important to identify the off-pulse interval of each pulsar accurately, since the properties of the off-pulse emissions are further researched by astrophysicists in an attempt to detect potential emissions from the associated pulsar wind nebula (PWN). The identification technique currently used in the literature is subjective in nature, since it is based on the visual inspection of the histogram estimate of the pulsar light curve. The developed nonparametric estimation technique is not only objective in nature, but also accurate in the estimation of the off-pulse interval of a pulsar, as evident from the simulation study and the application of the developed technique to observed pulsar data. The first two chapters of this thesis are devoted to a literature study that provides background information on the pulsar environment and -ray astronomy, together with an explanation of the on-pulse and off-pulse interval of a pulsar and the importance thereof for the present study. This is followed by a discussion on some fundamental circular statistical ideas, as well as an overview of kernel density estimation techniques. These two statistical topics are then united in order to illustrate kernel density estimation techniques applied to circular data, since this concept is the starting point of the developed nonparametric sequential estimation technique. Once the basic theoretical background of the pulsar environment and circular kernel density estimation has been established, the new sequential off-pulse interval estimator is formulated. The estimation technique will be referred to as `SOPIE'. A number of tuning parameters form part of SOPIE, and therefore the performed simulation study not only serves as an evaluation of the performance of SOPIE, but also as a mechanism to establish which tuning parameter configurations consistently perform better than some other configurations. In conclusion, the optimal parameter configurations are utilised in the application of SOPIE to pulsar data. For several pulsars, the sequential off-pulse interval estimators are compared to the off-pulse intervals published in research papers, which were identified with the subjective \eye-ball" technique. It is found that the sequential off-pulse interval estimators are closely related to the off-pulse intervals identified with subjective visual inspection, with the benefit that the estimated intervals are objectively obtained with a nonparametric estimation technique. / PhD (Statistics), North-West University, Potchefstroom Campus, 2014

The main objective of this thesis is the development of a nonparametric sequential estimation technique for the off-pulse interval(s) of a source function originating from a pulsar. It is important to identify the off-pulse interval of each pulsar accurately, since the properties of the off-pulse emissions are further researched by astrophysicists in an attempt to detect potential emissions from the associated pulsar wind nebula (PWN). The identification technique currently used in the literature is subjective in nature, since it is based on the visual inspection of the histogram estimate of the pulsar light curve. The developed nonparametric estimation technique is not only objective in nature, but also accurate in the estimation of the off-pulse interval of a pulsar, as evident from the simulation study and the application of the developed technique to observed pulsar data. The first two chapters of this thesis are devoted to a literature study that provides background information on the pulsar environment and -ray astronomy, together with an explanation of the on-pulse and off-pulse interval of a pulsar and the importance thereof for the present study. This is followed by a discussion on some fundamental circular statistical ideas, as well as an overview of kernel density estimation techniques. These two statistical topics are then united in order to illustrate kernel density estimation techniques applied to circular data, since this concept is the starting point of the developed nonparametric sequential estimation technique. Once the basic theoretical background of the pulsar environment and circular kernel density estimation has been established, the new sequential off-pulse interval estimator is formulated. The estimation technique will be referred to as `SOPIE'. A number of tuning parameters form part of SOPIE, and therefore the performed simulation study not only serves as an evaluation of the performance of SOPIE, but also as a mechanism to establish which tuning parameter configurations consistently perform better than some other configurations. In conclusion, the optimal parameter configurations are utilised in the application of SOPIE to pulsar data. For several pulsars, the sequential off-pulse interval estimators are compared to the off-pulse intervals published in research papers, which were identified with the subjective \eye-ball" technique. It is found that the sequential off-pulse interval estimators are closely related to the off-pulse intervals identified with subjective visual inspection, with the benefit that the estimated intervals are objectively obtained with a nonparametric estimation technique. / PhD (Statistics), North-West University, Potchefstroom Campus, 2014

O nadolol é um agente bloqueador de receptores β-adrenérgicos empregado principalmente, na \"angina pectoris\", hipertensão, certas arritmias cardíacas e no tratamento do glaucoma (SING, 2006). A ivermectina e a abamectina são fármacos que apresentam ação antiparasitária (SHOOP, 1995). Na presente pesquisa, a cromatografia em fase líquida de alta eficiência foi uma das técnicas estudadas para a quantificação dos enantiômeros do nadolol e dos homólogos presentes na abamectina e ivermectina. A versatilidade desta técnica reside no grande número de fases estacionárias existentes, as quais possibilitam análises, separações e determinações quantitativas de uma ampla gama de compostos com alta eficiência (Aquino Neto e Nunes, 2003). Para identificação dos enantiômeros do nadolol foi utilizado o dicroísmo circular que permite a determinação da configuração absoluta de enantiômeros (LIMA, 1997). Para os enantiômeros do nadolol e dos homólogos presentes na abamectina e na ivermectina também foram realizados testes para desenvolvimento de uma metodologia de quantificação por meio de uma técnica relativamente recente chamada de eletroforese capilar (EC), a qual tem alcançado desde sua introdução um rápido desenvolvimento e ampla aplicação na análise de fármacos em medicamentos (SANTORO, 2000). Para a comprovação da qualidade e segurança dos sistemas computadorizados dos equipamentos de cromatografia em fase líquida de alta eficiência (CLAE) e de eletroforese capilar (EC) foram efetuadas, neste trabalho, as respectivas validações. Após esta validação, pode-se confirmar o correto funcionamento de um software, e suas interações com o hardware, onde devem ser levados em consideração, dentre outros, os aspectos relacionados à infra-estrutura, segurança e manutenção de dados (AGÊNCIA NACIONAL DE VIGILÂNIA SANITÁRIA, 2010). As metodologias analíticas desenvolvidas a para quantificação do nadolol, abamectina e ivermectina por cromatografia em fase líquida de alta eficiência foram validadas. A validação analítica deve garantir, por meio de estudos experimentais, que o método atenda às exigências das aplicações analíticas, assegurando a confiabilidade dos resultados. Para tanto, o método deve apresentar especificidade, linearidade, intervalo, precisão, sensibilidade, limite de quantificação e detecção, exatidão, adequados à análise (AGÊNCIA NACIONAL DE VIGILÂNIA SANITÁRIA, 2003). Portanto, o objetivo proposto nesta pesquisa é primeiramente a validação dos sistemas computadorizados dos equipamentos de cromatografia em fase líquida de alta eficiência (CLAE) e de eletroforese capilar (EC). Para isto, serão desenvolvidos e validados os métodos analíticos de separação, identificação e quantificação dos enantiômeros do nadolol e dos homólogos presentes na abamectina e na ivermectina, em medicamentos, empregando as técnicas analíticas selecionadas. / Nadolol is a blocking agent with activity in the β -adrenergic receptors. It is mainly used in angina, hypertension, certain heart arrhythmias and in the treatment of glaucoma (SING, 2006). Ivermectin and abamectin are drugs with antiparasitic activity (SHOOP, 1995). In the present research, high performance liquid chromatography is one of the techniques used in the quantification of the enantiomers of nadolol and homologues present in abamectin and ivermectin. The versatility of this technique and the large number of existing stationary phases, enables the separation and quantitative determination of a wide range of compounds with high efficiency (Aquino Neto e Nunes, 2003). For identification of the nadolol enantiomers, circular dichroism was used which allows the determination of the absolute configuration of the enantiomers (LIMA, 1997). Nadolol enantiomers and the homologues present in abamectin and ivermectin will be also quantified by capillary zone electrophoresis (CE), a separation technique relatively recent, which has achieved, since its introduction, a wide application in the analysis of drugs in pharmaceutical preparations (SANTORO, 2000). In order to assure the quality of the analytical results, the computer systems of the liquid chromatograph and capillary electrophoresis equipments, must be validated prior to the analytical methods validation. Computer systems validation is used to verify and confirm the proper operation of softwares, and their interactions with the hardwares, besides the infrastructure, safety and storage of data (AGÊNCIA NACIONAL DE VIGILÂNIA SANITÁRIA, 2010). The analytical methodologies developed for quantification of nadolol, abamectin, ivermectin by using high efficiency liquid chromatography and capillary electrophoresis were validated. The analytical methods validation should ensure, through experimental studies, that the method meets the requirements for analytical applications, ensuring the reliability of the results. Parameters like, specificity, linearity, range, accuracy, sensitivity, limits of detection and quantification and accuracy, must be determined (AGÊNCIA NACIONAL DE VIGILÂNIA SANITÁRIA, 2003). The objective of this study is to validate the computer systems of the high performance liquid chromatograph and capillary electrophoresis equipments and then to develop and validate analytical methods for separation, identification and quantification of nadolol enantiomers and the homologues of abamectin and ivermectin.

As ligações de hidrogênio (LH), fundamentais na determinação da estrutura da água, proteínas, etc., são muito importantes no reconhecimento molecular e nos mecanismos de reações enzimáticas. A determinação da energia das LHs intramoleculares em proteínas e intermoleculares entre uma proteína e o solvente água, porque fornece informações sobre a estrutura secundária, terciária e quaternária das proteínas. Um método para quantificar e qualificar as LHs foi desenvolvido utilizando critérios de distância, geométricos e energéticos a partir das trajetórias obtidas por simulações de dinâmica molecular. O método foi testado com o monômero de uma fosfolipase A2 homodimérica, sem atividade catalítica, isolada do veneno da Bothrops asper(BaspMT-II). No dímero, a análise das LHs mostrou que elas são também essenciais na manutenção da estrutura quaternária. Essa análise permitiu identificar movimentos do tipo dobradiça acompanhados da formação transitória, na interface dimérica, de LHs controladas pelo triptofano na posição 77. Esses movimentos podem estar associados à ação danosa às membranas, uma vez que podem promover a inserção da região C-terminal na membrana. Estudos prévios mostraram que o peptídeo sintético (3Y codificado pelos aminoácidos 115-129 da BaspMT-II) apresenta atividade bactericida e citolítica. Um outro peptídeo (3W), mutante de 3Y, no qual três resíduos tirosina são substituidos por triptofano, apresenta um aumento do dano às membranas e do efeito miotóxico. Os mecanismos de ação desses peptídeos e as suas estruturas foram estudados por dinâmica molecular, dicroísmo circular (DC), microscopia de fluorescência e monocamadas de Langmuir (Mlang). As adsorções dos peptídeos em monocamadas de ácido dimiristoil fosfatídico (DMPA) e dimiristoilfosfatidilcolina (DMPC) se processam por mecanismos diferentes ocasionados pelas diferentes naturezas físico-químicas dos resíduos tirosina e triptofano. A microscopia de fluorescência acoplada a Mlang de DMPA com 3W adsorvido mostra um aumento da fluidez da monocamada, enquanto que o 3Y modifica os domínios do DMPA para pequenas estruturas circulares. Foram realizadas simulações dos peptídeos 3Y e 3W em meio aquoso e nas regiões interfaciais água/n-hexano e água/bicamadas de DMPC. Os resultados confirmam os obtidos por Mlang, demonstrando que os peptídeos interagem diferentemente com as membranas por adotar conformações alternativas definidas previamente. Essas conformações, diferentes das observadas em meio aquoso, dependem da natureza da interface. As estruturas encontradas no final das simulaçoes corroboram o mecanismo proposto por Mlang, assim como as estruturas sugeridas por DC. Isso sugere que a atividade biológica reduzida do peptídeo 3Y ocorre porque os seus dois resíduos Leu se adsorvem na interface sem penetrá-la. Ao contrário de 3W, os resíduos carregados do peptídeo 3Y não estão localizados corretamente para promover uma interação suficientemente atrativa para permitir a sua inserção na membrana celular. / Hydrogen bonds (HB) are highly important in the determination of the structure of the water and proteins. They also play a important role in molecular recognition and in enzyme reaction mechanisms. The determination of protein/water intermolecular and protein intramolecular HB energies provide information with respect to the formation and stabilization of secondary, tertiary and quaternary protein structure. A method that quantifies and qualifies the properties of HB was developed using distance, geometric and energy criteria as applied to data obtained from the atomic trajectories generated by molecular dynamics simulations. The method was tested with a monomer of a catalytically inactive homodimeric phospholipase A2 from Bothrops asper(BaspMT-II) venom. HBs at dimmer interface are essential for maintaining the quaternary structure, and are highly conserved during hinge-like movements of the dimmer. HB formed by tryptophan residue at position 77 controls this movement. These motions can be associated to the membrane damaging action since they facilitate the insertion of the C-terminus into the cellular membrane. Previous studies have shown that synthetic peptide (3Y, coding the amino acids 115-129 of BaspMT-II ) presents bactericidal and cytolitic activities. A peptide variant ( 3W ), in which tyrosine residues were substituted by tryptophan residues, presents an enhanced membrane damaging activity increased miotoxic effect. The mechanism of action of the peptides and their structures were studied by molecular dynamics simulations, circular dichroism (CD), fluorescence microscopy and Langmuir monolayers (Mlang). The adsorption of the peptides on a monolayer composed of dimiristoyl phosphatidic acid (DMPA) and dimiristoylphosphatidyl choline (DMPC) occurs through different processes due to the differences in the physic-chemical nature of the tyrosine and tryptophan residues. Fluorescence microscopy together with Mlang of DMPA with adsorbed 3W indicates an increase of the membrane fluidity while small circular domains are formed with DMPA. Simulations were conducted with the 3Y and 3W peptides in aqueous media, is a water/n-hexane and water/DMPC bilayers. The results confirm the Mlang results, showing that the peptides interact differently with the membranes by adopting alternative previously defined conformations. These two conformations, both of which are different to those observed in water, are dependent of the nature of the interfaces. The final simulated configurations confirm the mechanism proposed by Mlang and the structures proposed by CD. It is suggest that the reduced biological activity of the 3Y peptide is due to the two Leu residues that only adsorb to the cellular membrane without penetrating the bilayer. In contrast to the 3W peptide, no charged residue is correctly located to promote the interaction and insertion of the 3Y peptide into the membrane.

Os temas economia circular e gestão do ciclo de vida de produtos vem ganhando cada vez mais importância nos meios acadêmico e empresarial. Isso se deve a diversos fatores, como o risco de esgotamento de recursos naturais, o aumento do preço de commodities e um maior rigor das legislações. Fica cada vez mais evidente a necessidade de mudança do modelo linear para modelos circulares. Entretanto, a literatura carece de referências que auxiliem as organizações modificarem a gestão para atender essa necessidade. Apesar disso, são poucos os trabalhos que sistematizam as práticas e técnicas em modelos de referência para a gestão, fazendo com que as organizações não saibam por onde começar sua jornada rumo à economia circular. Assim, esta pesquisa tem como objetivo propor um modelo de gestão orientado à economia circular e à melhoria ambiental do ciclo de vida de produtos. O modelo em questão foi desenvolvido a partir de uma extensa revisão da literatura sobre os temas gestão do ciclo de vida, economia circular, sistemas de medição de desempenho e gestão ambiental. Os princípios, práticas e técnicas encontrados foram sistematizados na estrutura da ISO 14001:2015, resultando na primeira versão do modelo. Em seguida, o modelo foi avaliado por especialistas e profissionais da área de gestão ambiental, gestão do ciclo de vida e economia circular. Adicionalmente, foram realizados estudos de casos em empresas que adotam práticas de gestão do ciclo de vida e economia circular, com o intuito de se identificar novas práticas, instrumentos, além das barreiras que essas empresas enfrentam. Por fim, o modelo foi revisado e melhorado, resultado na versão final. O resultado desta pesquisa contribui para a teoria e prática de gestão organizacional, ao propor um modelo com práticas e técnicas, com base científica, ao passo que apresenta um guia para empresas inserirem práticas de gestão que suporte a transição para economia circular. / Circular economy and life cycle management have been have increasingly gained attention of researchers and practitioners. The risk of depletion of natural resources, the higher prices of commodities and strict laws are pushing companies towards a new way of doing business. The current linear model is no more suitable, but question like where and how to start this change have not yet been answered. There is a lack of studies that attempt to answer this question, especially regarding organizational management. This thesis aims to fill this gap by developing a management model oriented to circular economy and improvement of environmental performance of life cycle of products. The model was developed throughout an extensive literature review on life cycle management, circular economy, performance measurement and environmental management. The circular economy and life cycle management principles, practices and techniques were systemized into ISO 14001:2015 framework. Then, experts and practitioners evaluated the model answering a questionnaire. Next, cases studies were carried out in companies that adopt life cycle management and circular economy practices. The main purpose of cases studies was to identify circular economy and life cycle management practices and the main barriers to its implementation. Finally, the model were revised and improved. The management model contributes to literature, by framing practices and tools in phases and steps, while it presents a guide for companies to include circular economy and life cycle approach into business management.

Muitas espécies do gênero Aristolochia (Familia Aristolochiaceae) têm sido usadas na medicina tradicional e folclórica como medicamentos e tônicos, as quais demonstravam atividades farmacológicas de interesse clínica e medica como anti-hemorrágica, anti-parasita, antibacteriano, antifúngico, analgésico, antitumoral entre outras. Visando a obtenção de mais informações sobre essas plantas e na procura por substâncias com efeitos antiofídicos, neste trabalho avaliou-se à ação de extratos aquoso, metanólico e de acetato de etila de folhas e caule contra as ações tóxicas da peçonha de Bothrops asper, ambos procedentes do Panamá e contra o efeito miotóxico da peçonha de Bothrops jararacussu e das miotoxinas BthTX-I (isolada de B. jararacussu) e Mtx-II (isolada de B. asper). O extrato das folhas em acetato de etila apresentou a melhor inibição da atividade fosfolipásica da peçonha de B. asper, demonstrando inibição de 45%, 35% e 33% nas proporções de 1:5, 1:10 e 1:30 (m/m), respectivamente. Enquanto que, o extrato de caule em acetato de etila demonstrou maior eficácia na neutralização da atividade coagulante, e, além disso, inibiu 96%, 92% e 87% do edema, da miotoxicidade e hemorragia induzidas pela peçonha de B. asper, respectivamente. Os percentuais diferenciados na neutralização das ações tóxicas da peçonha de Bothrops asper, revelam diferentes perfis do potencial antiofídico de Aristolochia sprucei. Um dos componentes bioativos foi isolado do extrato de caule desta planta por CLAE, e a caracterização química, por ressonância magnética nuclear, demonstrou ser o ácido aristolóquio que inibiu a atividade miotóxica das peçonhas de B. jararacussu e de B. asper em 80% e 85% e assim como a atividade miotóxica da BthTX-I e Mtx-II em 64% e 60%, respectivamente. A atividade hemolítica indireta da peçonha de B. asper foi inibida em 43% pelo o ácido aristolóquio. A análise dos espectros de dicroísmo circular e os estudos de interação por modelagem molecular sugerem que o ácido aristolóquio forma um complexo com a Mtx-II de B. asper inibindo sua atividade. A ligação do ácido aristoloquio com as miotoxinas (MjTX-1, BthTX-II) modificou a forma e a intensidade dos espectros de dicroísmo circular da miotoxina e induziu alterações na porcentagem dos diversos domínios que constituem a estrutura secundária desta miotoxina. Os resultados obtidos confirmam que os extratos de A. sprucei possuem propriedades antiofídicas e sugerem a necessidade de aprofundar estudos que permitam utilizar com segurança os extratos e o principio ativo isolado como suplementos dos antisoros para aumentar a eficácia na neutralização dos efeitos tóxicos locais da peçonha das serpentes. / A lot of species of genus Aristolochia (Familia Aristolochiacheae) have been used in traditional medicine and folk, such as medicaments and tonics, which show pharmacological activities of clinic and medical interest, like antihemorragic, antiparasitic, antibacterial, antifungic, analgesic, antitumoral between others. Expecting to get more information about these plants and in the search by substances with antiophidic effects, in this work was evaluated the action of aqueous, metanolic and ethyl acetate extracts from leaves and stems of Aristolochia sprucei against the toxic action of Bothrops asper venom, both native from Panamá and against the myotoxic effect of Bothrops jararacussu venom and BthTX1 (isolated from B. jararacussu) and Mtx-II (isolated from Bothorps asper). The leaves extracts in ethyl acetate showed the best inhibition registered of PLA2 activity of venom de B. asper showing inhibition of 45 %, 35 % and 33 %, in proportion (m/m) of 1:5, 1:10 and 1:30 respectively. As regards to stem extract in ethyl acetate, it showed high efficacy in neutralization of coagulant activity, besides It inhibited 96 %, 92 % and 87 % of edema, myotoxicity and hemorrhage induced by B. asper venom, respectively. One of bioactives components was isolated from stem extract of this plant by CLAE and the chemical characterization by nuclear magnetic resonance, this showed that the compound is the aristolochic acid. This compound inhibited the myotoxic activity of B. jararacussu and B. asper venom in 80 % and 85 %, so like myotoxic activity of BthTx-I and MTx-II in 64 % and 60 % respectively. The indirect hemolytic activity of B. asper venom was inhibited in 43 % by the aristolochic acid. The analyze of spectrum of circular dichroism and the studies of interaction by molecular modelagem suggest that the aristolochic acid forms a complex 1:1 with the miotoxin inhibiting their activity. The joint of aristolochic acid with the miotoxins (MjTX-1, BthTx-II) changes the way and the intensity of spectra from dichroism circular of miotoxin and It induced alteration in percentage of several domains that constitute a secondary structure from this toxin. The results obtained confirm that the extracts of A. sprucei have antiophidic properties and it suggest the necessity of deepen studies that allow to use with safety the extracts and the isolated active principle, like antiserum supplements to increase the efficacy in the neutralization of local toxics effects of snakes venoms.

O nadolol é um agente bloqueador de receptores β-adrenérgicos empregado principalmente, na \"angina pectoris\", hipertensão, certas arritmias cardíacas e no tratamento do glaucoma (SING, 2006). A ivermectina e a abamectina são fármacos que apresentam ação antiparasitária (SHOOP, 1995). Na presente pesquisa, a cromatografia em fase líquida de alta eficiência foi uma das técnicas estudadas para a quantificação dos enantiômeros do nadolol e dos homólogos presentes na abamectina e ivermectina. A versatilidade desta técnica reside no grande número de fases estacionárias existentes, as quais possibilitam análises, separações e determinações quantitativas de uma ampla gama de compostos com alta eficiência (Aquino Neto e Nunes, 2003). Para identificação dos enantiômeros do nadolol foi utilizado o dicroísmo circular que permite a determinação da configuração absoluta de enantiômeros (LIMA, 1997). Para os enantiômeros do nadolol e dos homólogos presentes na abamectina e na ivermectina também foram realizados testes para desenvolvimento de uma metodologia de quantificação por meio de uma técnica relativamente recente chamada de eletroforese capilar (EC), a qual tem alcançado desde sua introdução um rápido desenvolvimento e ampla aplicação na análise de fármacos em medicamentos (SANTORO, 2000). Para a comprovação da qualidade e segurança dos sistemas computadorizados dos equipamentos de cromatografia em fase líquida de alta eficiência (CLAE) e de eletroforese capilar (EC) foram efetuadas, neste trabalho, as respectivas validações. Após esta validação, pode-se confirmar o correto funcionamento de um software, e suas interações com o hardware, onde devem ser levados em consideração, dentre outros, os aspectos relacionados à infra-estrutura, segurança e manutenção de dados (AGÊNCIA NACIONAL DE VIGILÂNIA SANITÁRIA, 2010). As metodologias analíticas desenvolvidas a para quantificação do nadolol, abamectina e ivermectina por cromatografia em fase líquida de alta eficiência foram validadas. A validação analítica deve garantir, por meio de estudos experimentais, que o método atenda às exigências das aplicações analíticas, assegurando a confiabilidade dos resultados. Para tanto, o método deve apresentar especificidade, linearidade, intervalo, precisão, sensibilidade, limite de quantificação e detecção, exatidão, adequados à análise (AGÊNCIA NACIONAL DE VIGILÂNIA SANITÁRIA, 2003). Portanto, o objetivo proposto nesta pesquisa é primeiramente a validação dos sistemas computadorizados dos equipamentos de cromatografia em fase líquida de alta eficiência (CLAE) e de eletroforese capilar (EC). Para isto, serão desenvolvidos e validados os métodos analíticos de separação, identificação e quantificação dos enantiômeros do nadolol e dos homólogos presentes na abamectina e na ivermectina, em medicamentos, empregando as técnicas analíticas selecionadas. / Nadolol is a blocking agent with activity in the β -adrenergic receptors. It is mainly used in angina, hypertension, certain heart arrhythmias and in the treatment of glaucoma (SING, 2006). Ivermectin and abamectin are drugs with antiparasitic activity (SHOOP, 1995). In the present research, high performance liquid chromatography is one of the techniques used in the quantification of the enantiomers of nadolol and homologues present in abamectin and ivermectin. The versatility of this technique and the large number of existing stationary phases, enables the separation and quantitative determination of a wide range of compounds with high efficiency (Aquino Neto e Nunes, 2003). For identification of the nadolol enantiomers, circular dichroism was used which allows the determination of the absolute configuration of the enantiomers (LIMA, 1997). Nadolol enantiomers and the homologues present in abamectin and ivermectin will be also quantified by capillary zone electrophoresis (CE), a separation technique relatively recent, which has achieved, since its introduction, a wide application in the analysis of drugs in pharmaceutical preparations (SANTORO, 2000). In order to assure the quality of the analytical results, the computer systems of the liquid chromatograph and capillary electrophoresis equipments, must be validated prior to the analytical methods validation. Computer systems validation is used to verify and confirm the proper operation of softwares, and their interactions with the hardwares, besides the infrastructure, safety and storage of data (AGÊNCIA NACIONAL DE VIGILÂNIA SANITÁRIA, 2010). The analytical methodologies developed for quantification of nadolol, abamectin, ivermectin by using high efficiency liquid chromatography and capillary electrophoresis were validated. The analytical methods validation should ensure, through experimental studies, that the method meets the requirements for analytical applications, ensuring the reliability of the results. Parameters like, specificity, linearity, range, accuracy, sensitivity, limits of detection and quantification and accuracy, must be determined (AGÊNCIA NACIONAL DE VIGILÂNIA SANITÁRIA, 2003). The objective of this study is to validate the computer systems of the high performance liquid chromatograph and capillary electrophoresis equipments and then to develop and validate analytical methods for separation, identification and quantification of nadolol enantiomers and the homologues of abamectin and ivermectin.